GOLF CLUB HEADS COMPRISING A VARIABLE FACE THICKNESS

Abstract

Described herein are embodiments of a variable face thickness strike face for a golf club. The golf club comprises a first transition region wherein the first transition region tapers the strike face thickness from a central region to either an intermediate region or an outer region. The first transition region may extend more in the high heel quadrant of the strike face than other sections to create constant CT across the face. In other embodiments, the first transition region can extend less into a sole portion than other sections to create constant CT across the face. In other embodiments, the first transition region can extend more into a desired quadrant or less into a desired quadrant to create constant CT across the face.

Description

TECHNICAL FIELD

This disclosure relates generally to strike faces of golf club heads and, more particularly, relates to strike faces having variable face thicknesses.

BACKGROUND

Characteristic time (CT) is a performance characteristic of a golf club that quantifies energy transfer from the golf club to a golf ball. A higher CT equates to more energy transfer and more distance. Consequently, golf's governing bodies limit CT to a predetermined upper limit. Golf clubs often have local areas of higher CT response, colloquially referred to as “hot spots,” that may cause a club to exceed the limit on CT. Accordingly, it is desirable for a club to have a more uniform or normalized CT response across the entire strike face. Further, a golf club with consistent CT across the face will perform similarly on miss hits and center strikes, thus allowing the golfer to more accurately predict distance. Varying the thickness of the face can alter CT response at various face locations. Generally, thicker regions of the strike face reduce CT and energy transfer, while thinner regions increase CT and energy transfer. Accordingly, it would be advantageous to provide a golf club head having a strike face with a variable face thickness that produced a more uniform CT response across the entire face.

BRIEF DESCRIPTION OF THE DRAWINGS

To facilitate further description of the embodiments, the following drawings are provided in which:

FIG. 1 illustrates a front perspective view of a golf club head.

FIG. 2 illustrates a bottom perspective view of the golf club head of FIG. 1.

FIG. 3A illustrates a front perspective view of the golf club head of FIG. 1.

FIG. 3B illustrates a front perspective view of the golf club head of FIG. 1.

FIG. 4 illustrates a front perspective view of the golf club head of FIG. 1.

FIG. 5 illustrates a toe-side perspective view of the golf club head of FIG. 1.

FIG. 6 illustrates a rear cross-sectional view, taken in a heel to toe direction of the golf club head of FIG. 1.

FIG. 7 illustrates a rear cross-sectional view, taken in a heel to toe direction of the golf club head of FIG. 1.

FIG. 8 illustrates a rear cross-sectional view, taken in a heel to toe direction of a golf club head according to another embodiment.

FIG. 9 illustrates a rear cross-sectional view, taken in a heel to toe direction of the golf club head of FIG. 1.

FIG. 10 illustrates a cross-sectional view, taken along a theta value of a portion of the strike face of the golf club head of FIG. 1, wherein the strike face is shown having a substantially linear contour to more clearly depict the thickness of the different regions.

FIG. 11 illustrates a cross-sectional view, taken along a different theta value of a portion of the strike face of the golf club head of FIG. 1, wherein the strike face is shown having a substantially linear contour to more clearly depict the thickness of the different regions.

FIG. 12 illustrates a cross-sectional view, taken along a different theta value of a portion of the strike face of the golf club head of FIG. 1, wherein the strike face is shown having a substantially linear contour to more clearly depict the thickness of the different regions.

FIG. 13 illustrates a cross-sectional view, taken along a different theta value of a portion of the strike face of the golf club head of FIG. 1, wherein the strike face is shown having a substantially linear contour to more clearly depict the thickness of the different regions.

FIG. 14 illustrates a cross-sectional view, taken along a different theta value of the strike face of the golf club head of FIG. 1, wherein the strike face is shown having a substantially linear contour to more clearly depict the thickness of the different regions.

FIG. 15 illustrates a cross-sectional view, taken along a different theta value of the strike face of the golf club head of FIG. 1, wherein the strike face is shown having a substantially linear contour to more clearly depict the thickness of the different regions.

FIG. 16 illustrates a cross-sectional view, taken along a different theta value of the strike face of the golf club head of FIG. 1, wherein the strike face is shown having a substantially linear contour to more clearly depict the thickness of the different regions.

FIG. 17 illustrates a cross-sectional view, taken along a different theta value of the strike face of the golf club head of FIG. 1, wherein the strike face is shown having a substantially linear contour to more clearly depict the thickness of the different regions.

FIG. 18 illustrates a cross-sectional view, taken along a different theta value of the strike face of the golf club head of FIG. 1, wherein the strike face is shown having a substantially linear contour to more clearly depict the thickness of the different regions.

FIG. 19 illustrates a cross-sectional view, taken along a different theta value of the strike face of the golf club head of FIG. 1, wherein the strike face is shown having a substantially linear contour to more clearly depict the thickness of the different regions.

FIG. 20 illustrates a cross-sectional view, taken along a different theta value of the strike face of the golf club head of FIG. 1.

FIG. 21 illustrates a cross-sectional view, taken along a different theta value of the strike face of the golf club head of FIG. 1.

FIG. 22 illustrates a rear cross-sectional view, taken in a heel to toe direction of the golf club head according to another embodiment.

FIG. 23 illustrates a CT map across an exemplary golf club.

FIG. 24 illustrates a rear cross-sectional view, taken in a heel to toe direction of prior art.

FIG. 25 illustrates a CT map across a control golf club.

FIG. 26 illustrates a CT map across an exemplary golf club.

FIG. 27 illustrates a CT map across an exemplary golf club.

FIG. 28 illustrates a cross-sectional view, taken in a heel to toe direction, a portion of the strike face of the golf club head of FIG. 1.

FIG. 29 illustrates a cross-sectional view, taken in a heel to toe direction, a portion of the strike face of the golf club head of FIG. 1.

FIG. 30 illustrates a rear cross-sectional view, taken in a heel to toe direction of the golf club head of FIG. 1.

FIG. 31 illustrates a rear cross-sectional view, taken in a heel to toe direction of the golf club head of FIG. 22.

FIG. 32 illustrates a rear perspective view of a golf club head comprising a crown insert and a sole insert.

FIG. 33 illustrates a rear perspective view of the golf club head of FIG. 32 comprising a crown opening and a sole opening.

FIG. 34 illustrates a rear perspective view of a golf club head comprising a central insert.

FIG. 35 illustrates a rear perspective view of the golf club head of FIG. 32 comprising a central opening.

FIG. 36 illustrates a cross-sectional view of a golf club head comprising a lightweight shaft-receiving structure.

FIG. 37 illustrates a cross-sectional view of the golf club head of FIG. 34 devoid of the shaft sleeve.

FIG. 38 illustrates a golf club head comprising a hosel mass zone.

FIG. 39 illustrates a golf club head comprising a mass pad.

DEFINITIONS

Described herein are golf club heads comprising a variable face thickness having more uniform CT across the face. The variable face thickness comprises a central region, a transition region, an intermediate region, a second transition region, and an outer region. Face thicknesses of these regions are selected to normalize CT across the strike face. The central region, the intermediate region, and the outer region may comprise the same or different constant thicknesses. The first transition region has a varying thickness extending from the central region to the intermediate region. In some embodiments, portions of the first transition region directly abut the second transition region. The second transition region has a varying thickness extending from the central region and/or the first transition region to the outer region.

For simplicity and clarity of illustration, the drawing figures illustrate the general manner of construction, and descriptions and details of well-known features and techniques may be omitted to avoid unnecessarily obscuring the invention. Additionally, elements in the drawing figures are not necessarily drawn to scale. For example, the dimensions of some of the elements in the figures may be exaggerated relative to other elements to help improve understanding of embodiments of the present invention. Additionally, in some figures the strike face is shown having a substantially linear contour to more clearly depict the thickness of the different regions. Other figures show the strike face with a generally arcuate contour to depict the bulge and roll curvature of the strike face. The same reference numerals in different figures denote the same elements.

The terms “first,” “second,” “third,” “fourth,” and the like in the description and in the claims, if any, are used for distinguishing between similar elements and not necessarily for describing a particular sequential or chronological order. It is to be understood that the terms so used are interchangeable under appropriate circumstances such that the embodiments described herein are, for example, capable of operation in sequences other than those illustrated or otherwise described herein. Furthermore, the terms “include,” and “have,” and any variations thereof, are intended to cover a non-exclusive inclusion, such that a process, method, system, article, device, or apparatus that comprises a list of elements is not necessarily limited to those elements but may include other elements not expressly listed or inherent to such process, method, system, article, device, or apparatus.

The terms “left,” “right,” “front,” “back,” “top,” “bottom,” “over,” “under,” and the like in the description and in the claims, if any, are used for descriptive purposes and not necessarily for describing permanent relative positions. It is to be understood that the terms so used are interchangeable under appropriate circumstances such that the embodiments of the invention described herein are, for example, capable of operation in other orientations than those illustrated or otherwise described herein.

The term “strike face,” as used herein, refers to the front of the golf club head comprising a variable thickness. The term strike face can be used interchangeably with the term “face.”

The term “strike face outer surface,” as used herein, refers to a club head front surface that is configured to strike a golf ball. The strike face outer surface terminates where the strike face outer surface curvature deviates from a bulge and/or roll of the strike face.

The term “strike face inner surface,” as used herein, refers to a club head rear surface that is on the inside of the interior cavity. The strike face inner surface terminates where the strike face inner surface curvature deviates from a bulge and/or roll of the strike face.

The term “thickness,” as used herein, refers to the thickness of the strike face, measured perpendicularly at any given point of the strike face, as the shortest distance between the strike face outer surface and the strike face inner surface, and measured tangential to strike face outer surface.

The term “strike face outer perimeter,” as used herein, can refer to an edge of the strike face outer surface. The strike face outer perimeter can be located along an outer edge of the strike face outer surface where the curvature deviates from a bulge and/or roll of the strike face. In embodiments where the strike face does not comprise bulge and roll (i.e., in an iron-type golf club head) the strike face outer perimeter can be defined as where the planar strike face outer surface deviates to a curved surface.

The term “strike face inner perimeter,” as used herein, can refer to an edge of the strike face inner surface. The strike face inner perimeter can be located along an outer edge of the strike face inner surface where the curvature deviates from a bulge and/or roll of the strike face. In embodiments where the strike face does not comprise bulge and roll (i.e., in an iron-type golf club head) the strike face inner perimeter can be defined as where the strike face inner surface, comprising a variable face thickness, deviates to a curved surface in the top rail, the sole, the heel and/or the toe.

The term “transition distance,” as used herein, can refer to the length of the first transition region surface along a given imaginary ray at a given theta (θ) value.

The term “theoretical first transition region perimeter,” as used herein, can refer to the shape the theoretical first transition length creates as it is swept radially about the central region perimeter. The theoretical transition region perimeter is the shape the first transition region would create if it were to extend all the way to the intermediate region thickness.

The term “first transition run,” as used herein, can refer to the distance between a point on the central perimeter and a point on the first transition perimeter on a given imaginary ray at a given theta (θ) value projected onto the loft plane and taken along the imaginary ray.

The term “thickness slope,” as used herein can refer to the slope of the first transition calculated by taking the difference in thickness between a point on the central perimeter and a point on the first transition perimeter, illustrated in FIG. 28 (first transition thickness change 139), on a given imaginary ray at a given theta (θ) value. and dividing it by the run.

The term “theoretical transition distance,” as used herein, can refer to the length of the first transition region surface along a given imaginary ray at a given theta (θ) value where the first transition region directly abuts the second transition region, and therefore does not actually reach the thickness of the intermediate region. The theoretical transition distance is the distance the first transition region would extend along the imaginary ray at a given theta (θ) value, at the same thickness slope, if it were to actually reach the intermediate region thickness.

The term “first transition rise,” as used herein refers to the difference in distance from the loft plane (measured perpendicular to the loft plane) between a point on the central perimeter and a point on the first transition perimeter illustrated in FIG. 29 (first transition rise 137), on a given imaginary ray at a given theta (θ) value.

The term “loft plane slope,” as used herein refers to the first transition rise divided by the run.

The term “high,” as used herein, refers to a crownward direction.

The term “low,” as used herein, refers to a soleward direction.

The term “geometric centerpoint,” or “geometric center” of the strike face, as used herein, can refer to a geometric centerpoint of the strike face perimeter, and at a midpoint of the face height of the strike face. In the same or other examples, the geometric centerpoint also can be centered with respect to an engineered impact zone, which can be defined by a region of grooves on the strike face. As another approach, the geometric centerpoint of the strike face can be located in accordance with the definition of a golf governing body such as the United States Golf Association (USGA).

The term “ground plane,” as used herein, can refer to a reference plane associated with the surface on which a golf ball is placed. The ground plane can be a horizontal plane tangent to the sole at an address position.

The term “loft plane,” as used herein, can refer to a reference plane that is tangent to the geometric centerpoint of the strike face.

The term “loft angle,” as used herein, can refer to an angle measured between the loft plane and the XY plane (defined below).

The term “face height,” as used herein, can refer to a distance measured parallel to loft plane between a top end of the strikeface perimeter and a bottom end of the strikeface perimeter.

The term “lie angle,” as used herein, can refer to an angle between a hosel axis, extending through the hosel, and the ground plane. The lie angle is measured from a front view.

The “depth” of the golf club head, as used herein, can be defined as a front-to-rear dimension of the golf club head.

The “height” of the golf club head, as used herein, can be defined as a crown-to-sole or top rail-to sole (pick one for iron or wood specific) dimension of the golf club head. In many embodiments, the height of the club head can be measured according to a golf governing body such as the United States Golf Association (USGA).

The “length” of the golf club head, as used herein, can be defined as a heel-to-toe dimension of the golf club head. In many embodiments, the length of the club head can be measured according to a golf governing body such as the United States Golf Association (USGA).

The “face height” of the golf club head, as used herein, can be defined as a height measured parallel to loft plane between a top end of the strike face perimeter near the crown or top rail (pick one for iron or wood specific) and a bottom end of the strike face perimeter near the sole.

The “geometric center height” of the fairway-type golf club head, as used herein, is a height measured perpendicular from the ground plane to the geometric center point of the golf club head.

The “leading edge” of the club head, as used herein, can be identified as the most sole-ward portion of the strike face perimeter.

An “XYZ” coordinate system of the golf club head, as described herein, is based upon the geometric center of the strike face. The golf club head dimensions as described herein can be measured based on a coordinate system as defined below. The geometric center of the strike face defines a coordinate system having an origin located at the geometric center of the strike face. The coordinate system defines an X axis 60, a Y axis 50, and a Z axis 70. The X axis extends through the geometric center of the strike face in a direction from the heel to the toe of the fairway-type club head. The Y axis extends through the geometric center of the strike face in a direction from the crown to the sole of golf club head. The Y axis is perpendicular to the X axis. The Z axis extends through the geometric center of the strike face in a direction from the front end to the rear end of the golf club head. The Z axis is perpendicular to both the X axis and the Y axis.

An “X′Y′Z′” coordinate system of the golf club head, as described herein, is based upon the central region geometric center. The VFT dimensions as described herein can be measured based on a coordinate system as defined below. The X′Y′Z′ coordinate system has an origin located at the central region geometric center. Further the X′Y′Z′ coordinate system is offset at an angle equal to the loft angle, such that the X′Y′ plane is parallel to the loft plane. The coordinate system defines an X′ axis 86, a Y′ axis 84, and a Z′ axis. The X′ axis extends through the central region geometric center in a direction from the heel to the toe of the fairway-type club head. The Y′ axis extends through the central region geometric center in a direction from the crown to the sole of golf club head. The Y′ axis is perpendicular to the X′ axis. The Z′ axis extends through the geometric center of the strike face in a direction from the front end to the rear end of the golf club head. The Z′ axis is perpendicular to both the X′ axis and the Y′ axis.

A “driver-type golf club head,” also referred to as a driver, as described herein, can be defined by specific dimensional ranges. In particular, the driver, as described with regard to the invention disclosed herein, includes a loft angle, volume, length, depth, and height within the ranges defined below.

The “loft angle” of the driver can be less than approximately 16 degrees, less than approximately 15 degrees, less than approximately 14 degrees, less than approximately 13 degrees, less than approximately 12 degrees, less than approximately 11 degrees, or less than approximately 10 degrees.

The volume of the driver can be greater than approximately 300 cm³, greater than approximately 350 cm³, greater than approximately 400 cm³, greater than approximately 425 cm³, greater than approximately 450 cm³, greater than approximately 475 cm³, greater than approximately 500 cm³, greater than approximately 525 cm³, greater than approximately 550 cm³, greater than approximately 575 cm³, greater than approximately 600 cm³, greater than approximately 625 cm³, greater than approximately 650 cm³, greater than approximately 675 cm³, or greater than approximately 700 cm³.

The height of the driver can be greater than 2.0 inches (50.8 mm) and less than 3.0 inches (76.2 mm), less than 2.9 inches (73.66 mm), less than 2.8 inches (71.12 mm), less than 2.7 (68.58 mm), or less than 2.6 inches (66.04 mm).

The face height of the driver can be between 1.3 inches (33 mm) and 3.8 inches (71 mm).

The driver can comprise a mass between 185 grams and 225 grams. The mass of the driver can range between 185 grams and 190 grams, between 190 grams and 195 grams, between 195 grams and 200 grams, between 200 grams and 205 grams, between 205 grams and 210 grams, between 210 grams and 215 grams, between 215 grams and 220 grams, or between 220 grams and 225 grams.

A “fairway-type golf club head” as defined herein is a club head having particular lofts, volumes, and dimensions that can be defined by specific dimensional ranges. In particular, the fairway-type club head, as described with regard to the invention disclosed herein, includes a loft angle, volume, length, depth, height, and face height within the ranges defined below. The specified ranges below limit the fairway-type golf club head to a fairway-type club head. In other words, the fairway-type golf club head cannot be a driver type, a hybrid-type, an iron-type, or a putter-type golf club head.

The “loft angle” of the fairway-type club head as defined herein can be less than approximately 35 degrees, less than approximately 34 degrees, less than approximately 33 degrees, less than approximately 32 degrees, less than approximately 31 degrees, or less than approximately 30 degrees. In some embodiments, the loft angle of the fairway-type golf club head can be greater than approximately 12 degrees, greater than approximately 13 degrees, greater than approximately 14 degrees, greater than approximately 15 degrees, greater than approximately 16 degrees, greater than approximately 17 degrees, greater than approximately 18 degrees, greater than approximately 19 degrees, or greater than approximately 20 degrees. For example, in some embodiments, the loft angle of the fairway-type golf club head can be between 14 degrees and 35 degrees, between 15 degrees and 35 degrees, between 20 degrees and 35 degrees, or between 12 degrees and 30 degrees.

The “volume” of the fairway-type club as described herein can be less than approximately 170 cm³, less than approximately 180 cm³, less than approximately 190 cm³, or less than approximately 200 cm³. However, the volume of the fairway-type club cannot be less than 160 cm³. In some embodiments, the volume of the fairway-type club head can be between approximately 150 cm³ to 200 cm³, between approximately 160 cm³ to 170 cm³, between approximately 160 cm³ to 180 cm³, or between approximately 170 cm³ to 190 cm³. The volume of the fairway-type club cannot be greater than 200 cm³. In one exemplary embodiment, the volume of the fairway-type club is 169 cm³.

The “depth” of the fairway-type golf club can be in a range of between 3.00 inches to 4.00 inches (76.2 mm to 101.6 mm). In some embodiments, the depth can be between 3.00 inches to 3.40 inches (76.2 mm to 86.36 mm), between 3.25 inches to 3.40 inches (82.55 mm to 86.36 mm), between 3.30 inches to 3.50 inches (83.82 mm to 88.90 mm), or between 3.50 inches to 4.00 inches (88.90 mm to 101.6 mm). The depth cannot be greater than 4.00 inches.

The “height” of the fairway-type golf club head can be in a range of between 1.25 inches to 2.00 inches (31.75 mm to 50.8 mm). In some embodiments, the height can be between 1.25 inches to 1.50 inches (31.75 mm to 38.10 mm), between 1.30 inches to 1.50 inches (33.02 mm to 38.10 mm), between 1.35 inches to 1.75 inches (34.29 mm to 44.45 mm), between 1.45 inches to 1.80 inches (36.83 mm to 45.72 mm), or between 1.50 inches to 2.00 inches (38.10 mm to 50.80 mm). In one exemplary embodiment, the height is 1.424 inches (36.17 mm). The height is not greater than 2.00 inches (50.80 mm).

The “length” of the fairway-type golf club head can be in a range of between 3.00 inches to 4.60 inches (76.2 mm to 116.84 mm). In some embodiments, the length can be between 3.00 inches to 4.00 inches to 4.40 inches (76.2 mm to 101.6 mm), between 4.25 inches to 4.40 inches (107.95 mm to 111.76 mm), or between 4.30 inches to 4.60 inches (109.22 mm to 116.84 mm). The length is not greater than 4.60 inches (116.84 mm).

The “face height” of the fairway-type golf club head can range from 1.00 inches to 1.50 inches (25.4 mm to 38.1 mm). In some embodiments, the face height can be between 1.00 inches to 1.25 inches (25.4 mm to 31.75 mm), between 1.00 inches to 1.15 inches (25.4 mm to 29.21 mm), between 1.15 inches to 1.35 inches (29.21 mm to 34.29 mm), or between 1.15 inches to 1.50 inches (29.21 mm to 38.1 mm).

The “geometric center height” of the fairway-type golf club head can range from 0.40 inch to 0.75 inch (10.16 mm to 19.05 mm). For example, the geometric center height can be between 0.40 inch to 0.60 inch (10.16 mm to 15.24 mm), between 0.50 inch to 0.70 inch (12.7 mm to 17.78 mm), or between 0.65 inch to 0.75 inch (16.51 mm to 19.05 mm).

The term “iron,” as used herein, can, in some embodiments, refer to an iron-type golf club head having a loft angle that is less than approximately 50 degrees, less than approximately 49 degrees, less than approximately 48 degrees, less than approximately 47 degrees, less than approximately 46 degrees, less than approximately 45 degrees, less than approximately 44 degrees, less than approximately 43 degrees, less than approximately 42 degrees, less than approximately 41 degrees, or less than approximately 40 degrees. Further, in many embodiments, the loft angle of the club head is greater than approximately 16 degrees, greater than approximately 17 degrees, greater than approximately 18 degrees, greater than approximately 19 degrees, greater than approximately 20 degrees, greater than approximately 21 degrees, greater than approximately 22 degrees, greater than approximately 23 degrees, greater than approximately 24 degrees, or greater than approximately 25 degrees.

In many embodiments, such as for “game improvement irons”, the volume of the club head is less than approximately 65 cm³, less than approximately 60 cm³, less than approximately 55 cm³, or less than approximately 50 cm³. In some embodiments, the volume of the club head can be approximately 50 cm³ to 60 cm³, approximately 51 cm³-53 cm³, approximately 53 cm³-55 cm³, approximately 55 cm³-57 cm³, or approximately 57 cm³-59 cm³.

In many embodiments, such as for “player's irons”, the volume of the club head is less than approximately 45 cm³, less than approximately 40 cm³, less than approximately 35 cm³, or less than approximately 30 cm³. In some embodiments, the volume of the club head can be approximately 31 cm³-38 cm³ (1.9 cubic inches to 2.3 cubic inches), approximately 31 cm³-33 cm³, approximately 33 cm³-35 cm³, approximately 35 cm³-37 cm³, or approximately 37 cm³-39 cm³.

In some embodiments, the iron can comprise a total mass ranging between 180 grams and 260 grams, 190 grams and 240 grams, 200 grams and 230 grams, 210 grams and 220 grams, or 215 grams and 220 grams. In some embodiments, the total mass of the club head is 215 grams, 216 grams, 217 grams, 218 grams, 219 grams, or 220 grams.

DESCRIPTION

Described herein are various embodiments of a golf club head comprising a variable face thickness. More specifically, outer peripheries of both a central region, having a relatively larger and constant central region thickness, and a first transition region, having a varying thickness, are located such that a radial distance between the two regions varies around the strike face when considered relative to a polar coordinate system. The first transition region may have different slopes at different angled imaginary rays emanating from a pole that coincides with a geometric center of the central region. The first transition region extends between the central region, comprising a first constant thickness, and an intermediate region, comprising a second constant thickness. The first constant thickness is greater than the second constant thickness. The varying slope of the first transition region and the varying distance between the outer peripheries of the central region and the first transition region normalize CT across the strike face.

In general, a golf club head 100 comprises a toe 102, a heel 104, a crown 106, a sole 108, a strike face 120, a geometric face center FC, and a hosel 111. In some embodiments, the golf club head 100 can comprise a composite portion 110. The composite portion 110 can comprise a portion of the crown 106, and/or the sole 108. In some embodiments, the golf club head 100 comprises a rear weight 190 and a rear weight receptacle 192. The golf club head 100 further comprises a strike face 120 variable thickness. The strike face 120 variable thickness comprises a central region 124, a first transition region 130, an intermediate region 136, a second transition region 140, and an outer region 146. The strike face 120 variable thickness can provide a constant CT across the strike face 120.

I. Central Region

The central region 124 is located proximate to the geometric face center FC. In some embodiments, the central region 124 comprises a central region geometric center 128 that is offset from the geometric face center FC when viewed in the loft plane 15. In other embodiments, the central region geometric center 128 aligns with the geometric face center FC when viewed in the loft plane 15. In some embodiments, the central region geometric center 128 is offset a y-axis distance and/or an x-axis distance from the geometric face center FC. When viewed from a rear of the strike face 120, the central region 124 can comprise symmetrical or non-symmetrical shapes. For example, the central region 124 may have a circular shape, an ovular shape, an ellipsoidal shape, a square shape, a triangular shape, a rectangular shape, or any other suitable shape. The shape of the central region 124 may be selected to normalize CT across the strike face 120.

The central region 124 can be offset−10 mm to 10 mm in the x-axis direction from the geometric face center FC. The central region 124 geometric center can be offset−10 mm to 10 mm in the y-axis direction from the geometric face center FC. The offset helps mitigate CT hotspots in the strike face 120 to normalize CT across the strike face 120.

The central region 124 can be angled relative to the x-axis. A central region offset angle can be measured between the x-axis and a line extending through a central region major axis. In many embodiments, the central region offset angle can range from 0 to 10 degrees. In other embodiments, the central region offset angle can range from 0 to 5 degrees, 5 to 10 degrees, 0 to 8 degrees, 1 to 9 degrees, or 2 to 10 degrees. For example, the central region offset angle can be 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 degrees. The central region offset angle can target specific locations of the strike face 120 to normalize CT.

An areal size of the central region 124 relative to that of the strike face 120 may be selected to normalize CT across the strike face 120. For example, the surface area of the central region 124 can comprise between 3% and 9% of the total surface area of a strike face inner surface 122. The disclosed percentages provide a variable strike face thickness profile that does not overly stiffen the face (i.e., reduce bending), but retains a constant CT across the strike face 120. If the central region 124 is too large, the strike face 120 is vulnerable to inconsistent CT values across the strike face 120. Furthermore, if the central region 124 is too large, the strike face 120 will be too stiff to provide adequate ball speed at impact. Conversely, if the surface area of the central region 124 is too small, the club head may be more prone to having CT hot spots.

Thus, the disclosed percentages provide a balance between thick and thin in turn, creating constant CT across the strike face 120.

In some embodiments, the central region 124 can comprise a surface area between 5 mm² to 305 mm². In some embodiments, the central region 124 can comprise a surface area between 5 mm² to 25 mm², 25 mm² to 45 mm², 45 mm² to 65 mm², 65 mm² to 85 mm², 85 mm² to 105 mm², 105 mm² to 125 mm², 125 mm² to 145 mm², 145 mm² to 165 mm², 165 mm² to 185 mm², 185 mm² to 205 mm², 205 mm² to 225 mm², 225 mm² to 245 mm², 245 mm² to 265 mm², 265 mm² to 285 mm², or 285 mm² to 305 mm². In some embodiments, the central region 124 can comprise a surface area greater than 5 mm², 25 mm², 45 mm², 65 mm², 85 mm², 105 mm², 125 mm², 145 mm², 165 mm², 185 mm², 205 mm², 225 mm², 245 mm², 265 mm², 285 mm², or 305 mm².

The central region 124 further comprises an overall width and height, measured along the X′ and Y′ axes, respectively. The overall width of the central region 124 may be between 12 mm and 26 mm (0.472 inch to 1.024 inches). In other embodiments, the central region 124 width may be between 12 mm and 14 mm (0.472 inch and 0.551 inch), 14 mm and 16 mm (0.551 inch and 0.630 inch), 16 mm and 18 mm (0.630 inch and 0.709 inch), 18 mm and 20 mm (0.709 inch and 0.787 inch), 20 mm and 22 mm (0.787 inch and 0.866 inch), 22 mm and 24 mm (0.866 inch and 0.945 inch), or 24 mm to 26 mm (0.866 inch to 1.024 inches). Further, the central region 124 height may be between 6 mm and 20 mm (0.236 inch and 0.787 inch). In other embodiments, the central region 124 height may be between 6 mm and 8 mm (0.236 inch and 0.315 inch), 8 mm and 10 mm (0.315 inch and 0.394 inch), 10 mm and 12 mm (0.394 inch and 0.472 inch), 12 mm and 14 mm (0.472 inch and 0.551 inch), 14 mm and 16 mm (0.551 inch and 0.630 inch), 16 mm and 18 mm (0.630 inch and 0.709 inch), or 18 mm and 20 mm (0.709 inch and 0.787 inch).

Relative to the face center FC, the width of the central region 124 comprises a heel-ward central region width and a toe-ward central region width. The heel-ward central region width can be between 5 mm and 17 mm (0.197 inch and 0.669 inch). In other embodiments, the heel-ward central region width may be between 5 mm and 7 mm (0.197 inch and 0.276 inch), 7 mm and 9 mm (0.276 in and 0.354 inch), 9 mm and 11 mm (0.354 inch and 0.433 inch), 11 mm and 13 mm (0.433 inch and 0.512 inch), 13 mm and 15 mm (0.512 inch and 0.591 inch), or 15 mm and 17 mm (0.591 inch and 0.669 inch). The toe-ward central region width may also be between 5 mm and 17 mm (0.197 inch and 0.669 inch). In other embodiments, the toe-ward central region width may be between 5 mm and 7 mm (0.197 inch and 0.276 inch), 7 mm and 9 mm (0.276 in and 0.354 inch), 9 mm and 11 mm (0.354 inch and 0.433 inch), 11 mm and 13 mm (0.433 inch and 0.512 inch), 13 mm and 15 mm (0.512 inch and 0.591 inch), or 15 mm and 17 mm (0.591 inch and 0.669 inch).

The height of the central region 124 can also be expressed in crown-ward central region height and a sole-ward central region height, relative to the face center FC. The crown-ward central region height may be between 2 mm and 10 mm (0.079 inch and 0.394 inch). In some embodiments, the crown-ward central region height may be between 2 mm and 4 mm (0.079 inch and 0.157 inch), 4 mm and 6 mm (0.157 inch and 0.236 inch), 6 mm and 8 mm (0.236 inch and 0.315 inch), or 8 mm and 10 mm (0.315 inch and 0.394 inch). Further, the sole-ward central region height may be between 2 mm and 10 mm (0.079 inch and 0.394 inch). In some embodiments, the sole-ward central region height may be between 2 mm and 4 mm (0.079 inch and 0.157 inch), 4 mm and 6 mm (0.157 inch and 0.236 inch), 6 mm and 8 mm (0.236 inch and 0.315 inch), or 8 mm and 10 mm (0.315 inch and 0.394 inch).

The central region 124 can comprise a thickness measured between a strike face outer surface 121 and a central region 124 internal surface (i.e., the strike face inner surface 122 within the central region 124). The central region 124 can comprise a constant thickness. Further, the central region 124 thickness is greater than an intermediate region 136 thickness, a first transition region 130 thickness, a second transition region 140 thickness, and an outer region 146 thickness. In other words, the central region 124 thickness may comprise a maximum face thickness of the strike face 120. Providing the maximum thickness proximate the geometric face center FC increases the stiffness of the strike face 120 within the central region 124, thereby limiting bending of the strike face 120 an reducing CT proximate the geometric face center FC. The central region 124 thickness can be between 2 mm and 4 mm (0.079 inch and 0.157 inch). The central region 124 thickness can be greater than 2.0 mm, 2.2 mm, 2.4 mm, 2.6 mm, 2.8 mm, 3.0 mm, 3.2 mm, 3.4 mm, 3.6 mm, 3.8 mm, or 4.0 mm.

II. Intermediate Region

The intermediate region 136 comprises a minimum thickness of the strike face 120 to increase CT away from the geometric face center FC, thereby normalizing CT across the strike face 120. In conventional thickness strike faces, impacts away from the geometric face center will have a lower CT. The central region 124, which decreases the CT due to a greater thickness, and the intermediate region 136, which increases CT due to a smaller thickness, combine to produce a strike face 120 with a normalized CT throughout the associated regions.

The intermediate region 136 is disposed outside of a first transition region perimeter 132, as illustrated in FIG. 7. The intermediate region 136 comprises a constant thickness, which may be less than the thickness of the central region 124, the first transition region 130, and the second transition region 140. The intermediate region 136 thickness can be between 1 mm and 3 mm (0.039 inch and 0.118 inch). The intermediate region 136 thickness can be greater than 1 mm, 1.2 mm, 1.4 mm, 1.6 mm, 1.8 mm, 2.0 mm, 2.2 mm, 2.4 mm, 2.6 mm, 2.8 mm, or 3.0 mm. The intermediate region 136 surface area can comprise between 7% and 55% of the strike face inner surface 122 surface area. The intermediate region 136 surface area can be selected to maintain a constant CT across the strike face 120. The disclosed percentages provide a strike face 120 variable thickness profile that balances increased bending in certain areas of the strike face 120 but retains a constant CT across the strike face 120. If the intermediate region 136 surface area is too large, the strike face 120 may have inconsistent CT values across the strike face 120, increasing the probability of hot spots on the strike face 120 and/or failure due to the lack of durability.

The intermediate region 136 transitions to an outer region 146 and has the strike face 120 minimum thickness to promote bending. The intermediate region 136 transitions to the outer region 146 via the second transition region 140. Increased bending close to the outer region 146 helps to normalize CT throughout the strike face 120. The golf club head 100 generally has more structural rigidity near the outer region 146, which is proximate a strike face inner perimeter 123b. Consequently, the strike face 120, proximate the strike face inner perimeter 123b, does not bend as much as the geometric face center FC. Hence, reducing thickness in the intermediate region 136 can increase CT in those strike face 120 areas thereby normalizing CT across the strike face 120. The intermediate region 136 can partially or fully surround the first transition region 130. In some embodiments, the intermediate region 136 can surround 50%-95% of the first transition region 130. In some embodiments the intermediate region 136 can surround 100% of the first transition region 130.

III. Angle Definition

The VFT may further be described with reference to a polar coordinate system, in which the strike face 120 may be divided into imaginary radial segments. These segments are formed by angles formed between the Y′ axis and an imaginary ray 82 emanating from the central region geometric center 128 in the X′Y′ plane. The segments may be bounded by rays extending at different angles. In some embodiments, angles (herein “theta (θ)”) of the rays may be 0°-15°, 15°-30°, 30°-45°, 45°-60°, 60°-75°, 75°-90°, 90°-105°, 105°-120°, 120°-135°, 135°-150°, 150°-165°, 165°-180°, 180°-195°, 195°-210°, 210°-225°, 225°-240°, 240°-255°, 255°-270°, 270°-285°, 285°-300°, 300°-315°, 315°-330°, 330°-345°), and 345°-360°. In other embodiments, the segments may be bounded by rays separated by 30 degrees, such that the segments are bounded by rays extending at 0°-30°, 30°-60°, 60°-90°, 90°-120°, 120°-150°, 150°-180°, 180°-210°, 210°-240°, 240°-270°, 270°-300°, 300°-330°), and 330°-360°. In some embodiments, 0°-90° defines the upper toe region of the strike face 120, 90°-180° defines the lower toe region of the strike face 120, 180°-270° defines the lower heel region of the strike face 120, and 270°-360° defines the upper heel region of the strike face 120. In some embodiments, each angle θ between 0° and 360° has an associated value and ranges, the theoretical first transition length 133a value and ranges, the strike face 120 thickness at the first transition region perimeter 132 value and ranges, the first transition included angle α value and ranges, the first transition rise 137 value and ranges, the first transition run value and ranges, the loft plane slope value and ranges, the first transition thickness change value and ranges, and the thickness slope value and ranges.

IV. First Transition Region

The first transition region 130 has a varying thickness that normalizes CT between the central region 124 and the intermediate region 136 illustrated in FIG. 7. The first transition region 130 region surrounds the central region 124. The slope of the first transition region 130, from the thicker central region to the thinner intermediate region, creates a normalized CT throughout the strike face 120. The thickness of the first transition region decreases as it extends further away from the central region 124 to increases CT, thereby offsetting CT loss associated with off-center impacts away from the central region 124.

The first transition region 130 connects the central region 124 to the intermediate region 136. In some embodiments, portions of the first transition region 130 connect directly to the intermediate region 136 and the second transition region 140, as discussed in further detail below. The first transition region 130 connecting to the intermediate region 136 and/or the second transition region 140 is illustrated in FIGS. 10-21. FIGS. 10-19 illustrate the strike face having a substantially linear contour to more clearly depict the thicknesses of the different regions. FIGS. 20 and 21 illustrate the strike face with a generally arcuate contour to depict bilge and roll curvature of the strike face. The first transition region perimeter 132 can be defined at the point where the strike face 120 thickness transitions from a varying thickness to a constant thickness and/or to an increase in thickness. The first transition region 130 thickness can be between 1.0 mm and 29.0 mm (0.039 inch and 1.142 inch).

The first transition region 130 may comprise different constant taper rates extending radially from the central region geometric center 128. The taper rate, in turn dictates an associated first transition region run at which the thickness of the first transition region 130 is equal to the thickness of the intermediate region 136. The first transition run 134 may vary based on the slope at a given angle theta (θ), creating various constant taper rates within the first transition region 130. Varying the first transition run 134 creates various constant taper rates throughout the first transition region 130.

The first transition region 130 has a size that can be described with reference to an overall first transition run 134 (alternatively referred to as first transition width), a first transition rise 137 (alternatively referred to as first transition height), and a first transition thickness change 139. The first transition run 134 and first transition rise 137 are measured along the X and Y axes, respectively. The overall width of the first transition region 130 may be between 55 mm and 80 mm (2.165 inches to 2.953 inches). In other embodiments, the first transition width (synonymous with the run) may be between 55 mm and 60 mm (2.165 inches and 2.362 inch), 60 mm and 65 mm (2.362 inches and 2.559 inch), 65 mm and 70 mm (2.559 inches and 2.756 inches), 70 mm and 75 mm (2.559 inches and 2.953 inches), or 75 mm and 80 mm (2.953 inches and 3.150 inches). Further, the first transition rise 137 may be between 20 mm and 55 mm (0.787 inch and 2.165 inches). In other embodiments, the first transition rise 137 may be between 20 mm and 25 mm (0.787 inch and 0.984 inch), 25 mm and 30 mm (0.984 inch and 1.181 inches), 30 mm and 35 mm (1.181 inches and 1.378 inches), 35 mm and 40 mm (1.378 inches and 1.575 inches), 40 mm and 45 mm (1.575 inches and 1.772 inches), 45 mm and 50 mm (1.772 inches and 1.969 inches), or 50 mm and 55 mm (1.969 inches and 2.165 inch).

The first transition run 134 comprises a heel-ward first transition run and a toe-ward first transition run. The first transition rise 137 comprises a crown-ward first transition rise and a sole-ward first transition rise, again relative to the face center. The heel-ward first transition run can be between 25 mm and 40 mm (0.984 inch and 1.575 inch). In other embodiments, the heel-ward first transition run may be between 25 mm and 28 mm (0.984 inch and 1.102 inches), 28 mm and 31 mm (1.102 inches and 1.220 inches), 31 mm and 34 mm (1.220 inches and 1.339 inches), 34 mm and 37 mm (1.339 inches and 1.457 inches), or 37 mm and 40 mm (1.457 inches and 1.575 inches). The toe-ward first transition run may also be between 25 mm and 40 mm (0.984 inch and 1.575 inch). In other embodiments, the heel-ward first transition run may be between 25 mm and 28 mm (0.984 inch and 1.102 inches), 28 mm and 31 mm (1.102 inches and 1.220 inches), 31 mm and 34 mm (1.220 inches and 1.339 inches), 34 mm and 37 mm (1.339 inches and 1.457 inches), or 37 mm and 40 mm (1.457 inches and 1.575 inches).

The crown-ward first transition rise and a sole-ward first transition rise, are measured from the face center along the Y axes. The crown-ward first transition rise may be between 5 mm and 30 mm (0.197 inch and 1.181 inches). In some embodiments, the crown-ward first transition rise may be between 5 mm and 10 mm (0.197 inch and 0.394 inch), 10 mm and 15 mm (0.394 inch and 0.591 inch), 15 mm and 20 mm (0.591 inch and 0.787 inch), 20 mm and 25 mm (0.787 inch and 0.984 inch), or 25 mm and 30 mm (0.984 inch and 1.181 inches). Further, the sole-ward first transition rise may be between 2 mm and 10 mm (0.079 inch and 0.394 inch). In some embodiments, the sole-ward first transition rise may be between 5 mm and 30 mm (0.197 inch and 1.181 inches). In some embodiments, the sole-ward first transition rise may be between 5 mm and 10 mm (0.197 inch and 0.394 inch), 10 mm and 15 mm (0.394 inch and 0.591 inch), 15 mm and 20 mm (0.591 inch and 0.787 inch), 20 mm and 25 mm (0.787 inch and 0.984 inch), or 25 mm and 30 mm (0.984 inch and 1.181 inches).

A. Slopes of First Transition Region

The taper rate of the first transition region 130 can be characterized by two different methods. In a first methodology for determining taper, a thickness slope is calculated by dividing the difference in thickness between a point on the central perimeter and a point on the first transition perimeter on a given imaginary ray 82 at a given theta (θ) value by the run illustrated in FIG. 28. In a second methodology for determining taper rate, a loft plane slope is calculated by dividing the rise, which is the difference in distance from the loft plane 15 (measured perpendicular to the loft plane 15) between a point on the central perimeter and a point on the first transition perimeter for a given imaginary ray 82 at a given theta (θ), by the run for the given imaginary ray 82 at the given theta (θ). Both methods of calculating the taper rate may be used to define identical structures in different ways. The greater the thickness slope and the loft plane slope, the faster the thickness of the first transition region 130 reaches that of the intermediate region 136 and/or the second transition region 140, thereby reducing the amount of material in the strike face 120 along the given imaginary ray 82 and increasing the CT closer to the geometric CT and normalizing the CT across the strike face 120. The lesser the thickness slope and the loft plane slope, the slower the thickness of the first transition region 130 reaches that of the intermediate region 136 and/or the second transition region 140, thereby increasing the amount of material in the strike face 120 along the given imaginary ray 82 and decreasing the CT closer to the geometric CT.

Each imaginary ray 82 may have a first transition region 130 with a thickness slope that differs from the thickness slope of another imaginary ray 82, thereby to adjust CT response of each ray. The thickness slope is calculated by taking the difference in thickness between a point on the central perimeter and a point on the first transition perimeter on a given imaginary ray 82 at a given theta (θ) value and dividing it by the run for the same given imaginary ray 82 at a given theta (θ). The thickness slope describes the rate at which the thickness of the strike face 120 changes from the central region 124 to the intermediate region 136 and may vary at different imaginary rays 82. The thickness slope at any given imaginary ray 82 may be between 0.03 and 0.30. In some segments, the thickness slope may be between 0.03 and 0.10, between 0.10 and 0.17, between 0.17 and 0.24, or between 0.24 and 0.30. Changing the thickness slope of the transition region at different imaginary rays 82 allows for the variable face thickness to comprise more thickness at different strike face 120 locations thereby normalizing the CT to the CT at geometric face center FC. In some embodiments, from a theta (θ) value of 140° to 220°

In embodiments comprising bulge and roll, each imaginary ray 82 can comprise a first transition region 130 with a loft plane slope that differs from the loft plane slope of another imaginary ray 82, thereby to adjust CT response of each segment. The loft plane slope is calculated taking the rise, which is the difference in distance from the loft plane 15 (measured perpendicular to the loft plane 15) between a point on the central perimeter and a point on the first transition perimeter for a given imaginary ray 82 at a given theta (θ), and dividing it by the run for the given imaginary ray 82 at a given theta (θ). The loft plane slope at any given imaginary ray 82 may be between 0.001 and 0.15. In some embodiments the loft plane slope can be greater than 0.020, 0.040, 0.060, 0.080, 0.100, 0.120, or 0.140 at any given imaginary ray 82.

A. Percent Intermediate Region Surrounds the First Transition Region

In some embodiments, the intermediate region 136 only partially surrounds the first transition region 130, in which case the first transition region 130 abuts both the intermediate region 136 and the second transition region 140. The intermediate region 136 may surround between 25% and 100% of the first transition region 130. In some embodiments, the intermediate region 136 may surround between 25% and 30%, between 30% and 35%, between 35% and 40%, between 40% and 45%, between 45% and 50%, between 45% and 55%, between 50% and 55%, between 55% and 60%, between 60% and 65%, between 65% and 70%, between 70% and 75%, between 75% and 80%, between 80% and 85%, between 85% and 90%, between 90% and 95%, or between 95% and 99.9% of the first transition region 130.

B. First Transition Region Perimeter

The first transition region perimeter 132 can be used to define a first transition run 134, and varying the first transition run 134 radially normalizes CT across the strike face 120. The first transition run 134 can be measured as the distance between the central region perimeter 126 and the first transition region perimeter 132 along an imaginary ray 82 emanating from the central region geometric center 128.

The first transition run 134 is variable around the strike face 120. The first transition run 134 may be between 5 mm and 39 mm (0.2 inch and 1.53 inches). Generally, the transition region distance is between 5 mm and 39 mm (0.2 inch and 1.53 inches) in the 0°-30° segment, between 5 mm and 39 mm (0.2 inch and 1.53 inches) in the 30°-60° segment, between 5 mm and 39 mm (0.2 inch and 1.53 inches) in the 60°-90° segment, between 5 mm and 39 mm (0.2 inch and 1.53 inches) in the 90°-120° segment, between 5 mm and 39 mm (0.2 inch and 1.53 inches) in the 120°-150° segment, between 5 mm and 39 mm (0.2 inch and 1.53 inches) in the 150°-180° segment, between 5 mm and 39 mm (0.2 inch and 1.53 inches) in the 180°-210° segment, between 5 mm and 39 mm (0.2 inch and 1.53 inches) in the 210°-240° segment, between 5 mm and 39 mm (0.2 inch and 1.53 inches) in the 240°-270° segment, between 5 mm and 39 mm (0.2 inch and 1.53 inches) in the 270°-300° segment, between 5 mm and 39 mm (0.2 inch and 1.53 inches) in the 300°-330° segment, and between 5 mm and 39 mm (0.2 inch and 1.53 inches) in the 330°-360° segment. A longer first transition run 134 results in more thickness across the strike face 120, which can be used to lower CT to a desired value. In some embodiments, the first transition run 134 is longest in the 270°-300°, 300°-330°), and the 330°-360° segments. Certain segments require different first transition runs 134 to achieve the optimal CT value.

A first transition length 135 can be measured as the length of the surface of the first transition region 130 along an imaginary ray 82. The first transition length 135 can be between 5 mm to 39 mm (0.197 inch and 1.535 inches). The first transition length 135 can be between 5 mm to 10 mm, 10 mm to 15 mm, 15 mm to 20 mm, 20 mm to 25 mm, 25 mm to 30 mm, 30 mm to 35 mm, or 35 mm to 39 mm.

A theoretical first transition length 133a can be taken as the length of the surface of the first transition region 130 along an imaginary ray 82 extending until the thickness of the first transition region 130 would hypothetically reach the thickness of the intermediate region 136. The theoretical first transition length 133a can be between 5 mm and 39 mm (0.197 inch and 1.535 inches). The theoretical first transition length 133a can be between 5 mm to 10 mm, 10 mm to 15 mm, 15 mm to 20 mm, 20 mm to 25 mm, 25 mm to 30 mm, 30 mm to 35 mm, or 35 mm to 39 mm.

The strike face 120 comprising a variable face thickness is shown in different cross-sectional views taken at different theta (θ) 84 values are illustrated in FIGS. 10-21. FIG. 10 illustrates a cross-sectional view taken at an angle θ of a portion of a strike face 120, and FIG. 11 illustrates a cross-sectional view taken at a different angle θ of a portion the strike face 120. Different angles from the Y′ axis 80 comprise various first transition runs 134, and the first transition runs 134 can be altered to provide different regions of the strike face 120 with the required thickness to maintain a constant CT throughout the strike face 120. In some embodiments, the first transition region 130 directly connects to the intermediate region 136 along a cross section taken along a given theta value (θ), illustrated in FIGS. 10, 11, 14, and 15. In some embodiments, the first transition region 130 directly connects to the intermediate region 136 and the second transition region 140 along a cross section taken along a given theta value (θ), illustrated in FIGS. 12, 13, 16, and 17. In some embodiments, the first transition region 130 directly connects to the second transition region 140 along a cross section taken along a given theta value (θ), as illustrated in FIGS. 18 and 19.

C. Angle Formed Between Transition Region and Central Region

The central region 124 abuts the first transition region 130 at the central region perimeter 126. This creates a first transition included angle α where the central region 124 and the first transition region 130 meet. The first transition included angle α is dependent upon the loft plane slope of the first transition region 130, illustrated in FIG. 10. For instance, a larger loft plane slope corresponds to a larger angle and a smaller loft plane slope corresponds to a smaller angle. The first transition included angle α can be inclusively between 0.1 degrees and 7.0 degrees. The first transition included angle α can be between 0.1 degrees to 0.4 degrees, 0.4 degrees to 0.7 degrees, 0.7 degrees to 1.0 degrees, 1.3 degrees to 1.6 degrees, 1.6 degrees to 1.9 degrees, 1.9 degrees to 2.2 degrees, 2.2 degrees to 2.5 degrees, 2.5 degrees to 2.8 degrees, 2.8 degrees to 3.1 degrees, 3.1 degrees to 3.4 degrees, 3.4 degrees to 3.7 degrees, or 3.7 degrees to 4.0 degrees.

V. Measurements

Described below is an exemplary embodiment comprising various theta (θ) values, associated with polar angles relative to a polar axis Y′, and the measurements associated with the values in one embodiment, as described herein. The first transition length 135 can be measured as the length of the surface of the first transition region 130 along an imaginary ray 82 for any given theta (θ) value. At any given theta (θ) value or theta (θ) range, the first transition length 135 can be between 5 mm and 30 mm. A larger first transition length 135 generally indicates a more gradual decrease in thickness and a similarly more gradual increase in CT response. A smaller first transition length 135, conversely, is associated with a more abrupt decrease in thickness and a similarly more abrupt increase in CT response. The first transition lengths at different polar angles can be selected to normalize CT response across the strike face. For example, at a first theta θ₁ (0°), the first transition length 135 can be between 12.0 mm to 14.0 mm (0.472 inch and 0.551 inch). In some embodiments, at the first theta θ₁ (0°), the first transition length 135 can be greater than 12.0 mm, 12.2 mm, 12.4 mm, 12.6 mm, 12.8 mm, 13.0 mm, 13.2 mm, 13.4 mm, 13.6 mm, 13.8 mm, or 14.0 mm. At a second theta θ₂ (30°), the first transition length 135 can be between 15.0 mm and 17.0 mm (0.590 inch and 0.669 inch). In some embodiments, at the second theta θ₂ (30°), the first transition length 135 can be greater than 15.0 mm, 15.2 mm, 15.4 mm, 15.6 mm, 15.8 mm, 16.0 mm, 16.2 mm, 16.4 mm, 16.6 mm, 16.8 mm, or 17.0 mm. At a third theta θ₃ (60°), the first transition length 135 can be between 17.0 mm to 20.0 mm (0.669 inch and 0.787 inch). In some embodiments, at the third theta θ₃ (60°), the first transition length 135 can be greater than 17.0 mm, 17.3 mm, 17.6 mm, 17.9 mm, 18.2 mm, 18.5 mm, 18.8 mm, 19.1 mm, 19.4 mm, 19.7 mm, or 20.0 mm. At a fourth theta θ₄ (90°), the first transition length 135 can be between 19.0 mm and 21.0 mm (0.75 inch and 0.8 inch). In some embodiments, at the fourth theta θ₄ (90°), the first transition length 135 can be greater than 19.0 mm, 19.2 mm, 19.4 mm, 19.6 mm, 19.8 mm, 20.0 mm, 20.2 mm, 20.4 mm, 20.6 mm, 20.8 mm, or 21.0 mm. At a fifth theta θ₅ (120°), the first transition length 135 can be between 12 mm to 18 mm (0.590 inch and 0.709 inch). In some embodiments, at the fifth theta θ₅ (120°), the first transition length 135 can be between 12.0 mm to 12.5 mm, 12.5 mm to 13.0 mm, 13.0 mm to 13.5 mm, 13.5 mm to 14.0 mm, 14.0 mm to 14.5 mm, 14.5 mm to 15.0 mm, 15.0 mm to 15.5 mm, 15.5 mm to 16.0 mm, 16.0 mm to 16.5 mm, 16.5 mm to 17.0 mm, 17.0 mm to 17.5 mm, or 17.5 mm to 18.0 mm. In some embodiments, at the fifth theta θ₅ (120°), the first transition length 135 can be greater than 12.0 mm, 12.5 mm, 13.0 mm, 13.5 mm, 14.0 mm, 14.5 mm, 15.0 mm, 15.5 mm, 16.0 mm, 16.5 mm, 17.0 mm, 17.5 mm, or 18.0 mm. At a sixth theta θ₆ (150°), the first transition length 135 can be between 8 mm to 16 mm (0.315 inch and 0.630 inch). In some embodiments, at the sixth theta θ₆ (150°), the first transition length 135 can be between 8 mm to 9 mm, 9 mm to 10 mm, 10 mm to 11 mm, 11 mm to 12 mm, 12 mm to 13 mm, 13 mm to 14 mm, 14 mm to 15 mm, or 15 mm to 16 mm. In some embodiments, at the sixth theta θ₆ (150°), the first transition length 135 can be greater than 8 mm, 9 mm, 10 mm, 11 mm, 12 mm, 13 mm, 14 mm, 15 mm, or 16 mm. At a seventh theta θ₇ (180°), the first transition length 135 can be between 7 mm to 14 mm (0.276 inch and 0.551 inch). In some embodiments, at the seventh theta θ₇ (180°), the first transition length 135 can be between 7 mm to 8 mm, 8 mm to 9 mm, 9 mm to 10 mm, 10 mm to 11 mm, 11 mm to 12 mm, 12 mm to 13 mm, or 13 mm to 14 mm. In some embodiments, at the seventh theta θ₇ (180°), the first transition length 135 can be greater than 7 mm, 8 mm, 9 mm, 10 mm, 11 mm, 12 mm, 13 mm, or 14 mm. At an eighth theta θ₈ (210°), the first transition length 135 can be between 8 mm to 16 mm (0.315 inch and 0.630 inch). In some embodiments, at the eighth theta θ₈ (210°), the first transition length 135 can be between 8 mm to 9 mm, 9 mm to 10 mm, 10 mm to 11 mm, 11 mm to 12 mm, 12 mm to 13 mm, 13 mm to 14 mm, 14 mm to 15 mm, or 15 mm to 16 mm. In some embodiments, at the eighth theta θ₈ (210°), the first transition length 135 can be greater than 8 mm, 9 mm, 10 mm, 11 mm, 12 mm, 13 mm, 14 mm, 15 mm, or 16 mm. At a ninth theta θ₉ (240°), the first transition length 135 can be between 15 mm to 19 mm (0.591 inch and 0.748 inch). In some embodiments, at the ninth theta θ₉ (240°), the first transition length 135 can be between 15 mm to 15.5 mm, 15.5 mm to 16 mm, 16 mm to 16.5 mm, 16.5 mm to 17 mm, 17.5 mm to 18 mm, 18 mm to 18.5 mm, or 18.5 mm to 19 mm. In some embodiments, at the ninth theta θ₉ (240°), the first transition length can be greater than 15 mm, 15.5 mm, 16 mm, 16.5 mm, 17 mm, 17.5 mm, 18 mm, 18.5 mm, or 19 mm. At a tenth theta θ₁₀ (270°), the first transition length 135 can be between 22 mm to 26 mm (0.866 inch and 1.024 inch). In some embodiments, at the tenth theta θ₁₀ (270°), the first transition length 135 can be greater than 22 mm, 22.5 mm, 23 mm, 23.5 mm, 24 mm, 24.5 mm, 25 mm, 25.5 mm, or 26 mm. At an eleventh theta θ₁₁ (285°), the first transition length 135 can be between 22 mm to 26 mm (0.866 inch and 1.024 inch). In some embodiments, at the eleventh theta θ₁₁ (285°), the first transition length 135 can be greater than 22 mm, 22.5 mm, 23 mm, 23.5 mm, 24 mm, 24.5 mm, 25 mm, 25.5 mm, or 26 mm. At a twelfth theta θ₁₂ (300°), the first transition length 135 can be between 19 mm to 21 mm (0.748 inch and 0.827 inch). In some embodiments, at the twelfth theta θ₁₂ (300°), the first transition length 135 can be greater than 19 mm, 19.5 mm, 20 mm, 20.5 mm, or 21 mm. At a thirteenth theta @13) (330°), the first transition length 135 can be between 12 mm to 16 mm (0.472 inch and 0.630 inch). In some embodiments, at the thirteenth theta θ₁₃ (330°), the first transition length 135 can be greater than 12 mm, 12.5 mm, 13 mm, 13.5 mm, 14 mm, 14.5 mm, 15 mm, 15.5 mm, or 16 mm.

The theoretical first transition length 133a can be measured when at least a portion of the first transition region 130 is truncated and therefore directly abuts the second transition region 140. As such, the theoretical transition length represents the length at which the thickness of the first transition region 130 along the angle theta (θ) would be equal to the intermediate region assuming the slope (either the loft plane slope or thickness slope) was constant. At any given theta (θ) value or theta (θ) range, the theoretical first transition length 133a can be between 10 mm and 35 mm (0.393 inch and 1.378 inches). A larger theoretical first transition length 133a, generally indicates a more gradual decrease in thickness, resulting in a more gradual increase in CT. A smaller theoretical first transition length 133a, conversely indicates a more abrupt decrease in thickness resulting in a more abrupt increase in CT. For example, at a first theta θ₁ (0°), the theoretical first transition length 133a can be between 13 mm and 15 mm (0.512 inch and 0.590 inch). In some embodiments, at the first theta θ₁ (0°), the theoretical first transition length 133a can be greater than 13 mm, 13.5 mm, 14 mm, 14.5 mm, or 15 mm. At a second theta θ₂ (30°), the theoretical first transition length 133a can be between 15 mm to 17 mm (0.591 inch and 0.669 inch). In some embodiments, at the second theta θ₂ (30°), the theoretical first transition length 133a can be greater than 15 mm, 15.5 mm, 16 mm, 16.5 mm, or 17 mm. At a third theta θ₃ (60°), the theoretical first transition length 133a can be between 17 mm to 20 mm (0.669 inch and 0.787 inch). In some embodiments, at the third theta θ₃ (60°), the theoretical first transition length 133a can be greater than 17 mm, 17.5 mm, 18 mm, 18.5 mm, 19 mm, 19.5 mm, or 20 mm. At a fourth theta θ₄ (90°), the theoretical first transition length 133a can be between 19 mm to 21 mm (0.748 inch and 0.827 inch). In some embodiments, at the fourth theta θ₄ (90°), the theoretical first transition length 133a can be greater than 19 mm, 19.5 mm, 20 mm, 20.5 mm, or 21 mm. At a fifth theta θ₅ (120°), the theoretical first transition length 133a can be between 12 mm to 18 mm (0.590 inch and 0.709 inch). In some embodiments, at the fifth theta θ₅ (120°), the theoretical first transition length 133a can be between 12.0 mm to 12.5 mm, 12.5 mm to 13.0 mm, 13.0 mm to 13.5 mm, 13.5 mm to 14.0 mm, 14.0 mm to 14.5 mm, 14.5 mm to 15.0 mm, 15.0 mm to 15.5 mm, 15.5 mm to 16.0 mm, 16.0 mm to 16.5 mm, 16.5 mm to 17.0 mm, 17.0 mm to 17.5 mm, or 17.5 mm to 18.0 mm. In some embodiments, at the fifth theta θ₅) (120°), the theoretical first transition length 133a can be greater than 12.0 mm, 12.5 mm, 13.0 mm, 13.5 mm, 14.0 mm, 14.5 mm, 15.0 mm, 15.5 mm, 16.0 mm, 16.5 mm, 17.0 mm, 17.5 mm, or 18.0 mm. At a sixth theta θ₆ (150°), the theoretical first transition length 133a can be between 8 mm to 16 mm (0.315 inch and 0.630 inch). In some embodiments, at the sixth theta θ₆ (150°), the theoretical first transition length 133a can be between 8 mm to 9 mm, 9 mm to 10 mm, 10 mm to 11 mm, 11 mm to 12 mm, 12 mm to 13 mm, 13 mm to 14 mm, 14 mm to 15 mm, or 15 mm to 16 mm. In some embodiments, at the sixth theta θ₆ (150°), the theoretical first transition length 133a can be greater than 8 mm, 9 mm, 10 mm, 11 mm, 12 mm, 13 mm, 14 mm, 15 mm, or 16 mm. At a seventh theta θ₇ (180°), the theoretical first transition length 133a can be between 7 mm to 14 mm (0.276 inch and 0.551 inch). In some embodiments, at the seventh theta θ₇ (180°), the theoretical first transition length 133a can be between 7 mm to 8 mm, 8 mm to 9 mm, 9 mm to 10 mm, 10 mm to 11 mm, 11 mm to 12 mm, 12 mm to 13 mm, or 13 mm to 14 mm. In some embodiments, at the seventh theta θ₇ (180°), the theoretical first transition length 133a can be greater than 7 mm, 8 mm, 9 mm, 10 mm, 11 mm, 12 mm, 13 mm, or 14 mm. At an eighth theta θ₈ (210°), the theoretical first transition length 133a can be between 8 mm to 16 mm (0.315 inch and 0.630 inch). In some embodiments, at the eighth theta θ₈ (210°), the theoretical first transition length 133a can be between 8 mm to 9 mm, 9 mm to 10 mm, 10 mm to 11 mm, 11 mm to 12 mm, 12 mm to 13 mm, 13 mm to 14 mm, 14 mm to 15 mm, or 15 mm to 16 mm. In some embodiments, at the eighth theta θ₈ (210°), the theoretical first transition length 133a can be greater than 8 mm, 9 mm, 10 mm, 11 mm, 12 mm, 13 mm, 14 mm, 15 mm, or 16 mm. At a ninth theta θ₉ (240°), the theoretical first transition length 133a can be between 15 mm to 19 mm (0.591 inch and 0.748 inch). In some embodiments, at the ninth theta θ₉ (240°), the theoretical first transition length 133a can be between 15 mm to 15.5 mm, 15.5 mm to 16 mm, 16 mm to 16.5 mm, 16.5 mm to 17 mm, 17.5 mm to 18 mm, 18 mm to 18.5 mm, or 18.5 mm to 19 mm. In some embodiments, at the ninth theta θ₉ (240°), the theoretical first transition length 133a can be greater than 15 mm, 15.5 mm, 16 mm, 16.5 mm, 17 mm, 17.5 mm, 18 mm, 18.5 mm, or 19 mm. At a tenth theta θ₁₀ (270°), the theoretical first transition length 133a can be between 22 mm to 26 mm (0.866 inch and 1.024 inch). In some embodiments, at the tenth theta θ₁₀ (270°), the first transition length 133a can be greater than 22 mm, 22.5 mm, 23 mm, 23.5 mm, 24 mm, 24.5 mm, 25 mm, 25.5 mm, or 26 mm. At an eleventh theta θ₁₁ (285°), the theoretical first transition length 133a can be between 22 mm to 31 mm (0.866 inch and 1.220 inch). In some embodiments, at the eleventh theta θ₁₁ (285°), the theoretical first transition length 133a can be between 22 mm to 23 mm, 23 mm to 24 mm, 24 mm to 25 mm, 25 mm to 26 mm, 26 mm to 27 mm, 27 mm to 28 mm, 28 mm to 29 mm, 29 mm to 30 mm, or 30 mm to 31 mm. In some embodiments, at the eleventh theta @11) (285°), the theoretical first transition length 133a can be greater than 22 mm, 23 mm, 24 mm, 25 mm, 26 mm, 27 mm, 28 mm, 29 mm, 30 mm, or 31 mm. At a twelfth theta θ₁₂ (300°), the theoretical first transition length 133a can be between 19 mm to 26 mm (0.748 inch and 1.024 inch). In some embodiments at the θ₁₂ (300°), the theoretical first transition length 133a can be between 19 mm to 20 mm, 20 mm to 21 mm, 21 mm to 22 mm, 22 mm to 23 mm, 23 mm to 24 mm, 24 mm to 25 mm, or 25 mm to 26 mm. In some embodiments, at the twelfth theta θ₁₂ (300°), the theoretical first transition length 133a can be greater than 19 mm, 20 mm, 21 mm, 22 mm, 23 mm, 24 mm, 25 mm, or 26 mm. At a thirteenth theta θ₁₃ (330°), the theoretical first transition length 133a can be between 12 mm to 17 mm (0.472 inch and 0.669 inch). In some embodiments, at the thirteenth theta θ₁₃ (330°), the theoretical first transition length 133a can be between 12 mm to 13 mm, 13 mm to 14 mm, 14 mm to 15 mm, 15 mm to 16 mm, or 16 mm to 17 mm. In some embodiments, at the thirteenth theta θ₁₃ (330°), the theoretical first transition length 133a can be greater than 12 mm, 13 mm, 14 mm, 15 mm, 16 mm, or 17 mm.

The thickness at the first transition region perimeter 132 can vary in different radial segments, so that thicker segments will reduce CT and thinner segments will increase CT, thereby to normalize CT across the face. At any given theta (θ) value or theta (θ) range, the strike face 120 thickness at the first transition region perimeter 132 can be between 1.5 mm and 3.5 mm (0.059 inch and 0.138 inch). For example, at a first theta θ₁ (0°), the thickness at the first transition region perimeter 132 can be between 2.0 mm and 2.5 mm (0.079 inch and 0.098 inch). In some embodiments, at the first theta θ₁ (0°), the thickness at the first transition region perimeter 132 can be greater than 2.0 mm, 2.1 mm, 2.2 mm, 2.3 mm, 2.4 mm, or 2.5 mm. At a second theta θ₂ (30°), a third theta θ₃ (60°), a fourth theta θ₄ (90°), a fifth theta θ₅ (120°), an eighth theta θ₈ (210°), a ninth theta θ₉ (240°), and/or a tenth theta θ₁₀ (270°), the thickness at the first transition region perimeter 132 can be between 1.7 mm and 2.1 mm (0.067 inch and 0.083 inch). In some embodiments, at the second theta θ₂ (30°), a third theta θ₃ (60°), a fourth theta θ₄ (90°), a fifth theta θ₅ (120°), an eighth theta θ₈ (210°), a ninth theta θ₉ (240°), and/or a tenth theta θ₁₀ (270°), the thickness at the first transition region perimeter 132 can be greater than 1.7 mm, 1.8 mm, 1.9 mm, 2.0 mm, or 2.1 mm. At a sixth theta θ₆ (150° and/or a seventh theta θ₇ (180°), the strike face 120 thickness at the first transition region perimeter 132 can be between 1.7 mm and 2.2 mm (0.067 inch and 0.087 inch). In some embodiments, at the sixth theta θ₆ (150° and/or a seventh theta θ₇ (180°), the strike face 120 thickness at the first transition region perimeter 132 can be greater than 1.7 mm, 1.8 mm, 1.9 mm, 2.0 mm, 2.1 mm, or 2.2 mm. At an eleventh theta θ₁₁ (285°), the thickness at the first transition region perimeter 132 can be between 1.7 mm and 2.3 mm (0.067 inch and 0.091 inch). In some embodiments, at the eleventh theta θ₁₁ (285°), the thickness at the first transition region perimeter 132 can be greater than 1.7 mm, 1.8 mm, 1.9 mm, 2.0 mm, 2.1 mm, 2.2 mm, or 2.3 mm. At a twelfth theta θ₁₂ (300°), strike face 120 thickness at the first transition region perimeter 132 can be between 2.1 mm and 2.5 mm (0.083 inch and 0.098 inch). In some embodiments, at the twelfth theta θ₁₂ (300°), the thickness at the first transition region perimeter 132 can be greater than 2.1 mm, 2.2 mm, 2.3 mm, 2.4 mm, or 2.5 mm. At a thirteenth theta θ₁₃ (330°), the thickness at the first transition region perimeter 132 can be between 2.0 mm and 2.3 mm (0.079 inch and 0.091 inch). In some embodiments, at the thirteenth theta θ₁₃ (330°), the thickness at the first transition region perimeter 132 can be greater than 2.0 mm, 2.1 mm, 2.2 mm, or 2.3 mm.

The first transition included angle α is indicative of slope of the first transition region, with a larger value indicating greater slope and a lower value indicating lesser slope. The first transition included angle α is the angle measured between a plane parallel to the loft plane 15 and intersecting the central region perimeter 126 along an imaginary ray 82 for any given theta (θ) value. Controlling the first transition included angle α to a desired value controls how the first transition region 130 extends outward from the central region 124 and how much material is located in different regions of the strike face 120 thereby normalizing CT across the strike face 120. At any given theta (θ) value or theta (θ) range, the first transition included angle α can be between 0.1° and 8°. At a first theta θ₁ (0°), the first transition included angle α can be between 1.75° and 2.5°. In some embodiments, at the first theta θ₁ (0°), the first transition included angle α can be greater than 1.75°, 2.0°, 2.25°), or 2.5°. At a second theta θ₂ (30°), the first transition included angle α can be between 1.25° and 2.0°. In some embodiments, at the second theta θ₂ (30°), the first transition included angle α can be greater than 1.25°, 1.5°, 1.75°), or 2.0°. At a third theta θ₃ (60°), the first transition included angle α can be between 0.05° and 0.7°. In some embodiments, at the third theta θ₃ (60°), the first transition included angle α can be greater than 0.05°, 0.1°, 0.2°, 0.3°, 0.4°, 0.5°, 0.6°), or 0.7°. At a fourth theta θ₄ (90°), the first transition included angle α can be between 0.05° and 0.15°. In some embodiments, at the fourth theta θ₄) (90°), the first transition included angle α can be greater than 0.05°, 0.1°, 0.2°, 0.3°, 0.4°, 0.5°, 0.6°), or 0.7°. At a fifth theta θ₅ (120°), the first transition included angle α can be between 0.05° and 2.5°. In some embodiments, at the fifth theta θ₅ (120°), the first transition included angle α can be between 1.5° and 2.0° or 2.0° and 2.5°. In some embodiments, at the fifth theta θ₅ (120°), the first transition included angle α can be greater than 1.5°, 2.0°), or 2.5°. At a sixth theta θ₆ (150°), the first transition included angle α can be between 1.25° and 5.5°. In some embodiments, at the sixth theta θ₆ (150°), the first transition included angle α can be between 1.25° and 1.5°, 1.5° and 2.0°, 2.0° and 2.5°, 2.5° and 3.0°, 3.0° and 3.5°, 3.5° and 4.0°, 4.5° and 5.0°), or 5.0° and 5.5°. In some embodiments, at the sixth theta θ₆ (150°), the first transition included angle α can be greater than 1.25°, 1.5°, 2.0°, 2.5°, 3.0°, 3.5°, 4.0°, 4.5°, 5.0°), or 5.5°. At a seventh theta θ₇ (180°), the first transition included angle α can be between 1.25° and 6.5°. In some embodiments, at the seventh theta θ₇ (180°), the first transition included angle α can be between 1.25° and 1.5°, 1.5° and 2.0°, 2.0° and 2.5°, 2.5° and 3.0°, 3.0° and 3.5°, 3.5° and 4.0°, 4.5° and 5.0°, 5.0° and 5.5°, 5.5° and 6.0°), or 6.0° and 6.5°. In some embodiments, at the seventh theta θ₇ (180°), the first transition included angle α can be greater than 1.25°, 1.5°, 2.0°, 2.5°, 3.0°, 3.5°, 4.0°, 4.5°, 5.0°, 5.5°, 6.0°), or 6.2°. At an eighth theta θ₈ (210°), the first transition included angle α can be between 1.25° and 5.0°. In some embodiments, at the eighth theta θ₈ (210°), the first transition included angle α can be between 1.25° and 1.5°, 1.5° and 2.0°, 2.0° and 2.5°, 2.5° and 3.0°, 3.0° and 3.5°, 3.5° and 4.0°), or 4.5° and 5.0°. In some embodiments, at the eighth theta θ₈ (210°), the first transition included angle α can be greater than 1.25°, 1.5°, 2.0°, 2.5°, 3.0°, 3.5°, 4.0°, 4.5°), or 5.0°. At a ninth theta θ₉ (240°), the first transition included angle α can be between 0.5° and 1.5°. In some embodiments, at the ninth theta θ₉ (240°), the first transition included angle first transition included angle α can be greater than 0.5°, 1.0°), or 1.5°. At a tenth theta θ₁₀ (270°), the first transition included angle α can be between 0.75° and 1.75°. In some embodiments, at the tenth theta θ₁₀ (270°), the first transition included angle α can be greater than 0.75°, 1.0°, 1.25°, 1.5°), or 1.75°. At an eleventh theta θ₁₁ (285°), the first transition included angle α can be between 0.5° and 1.5°. In some embodiments, at the eleventh theta θ₁₁ (285°), the first transition included angle α can be greater than 0.5°, 1.0°), or 1.5°. At a twelfth theta θ₁₂ (300°), the first transition included angle α can be between 0.05° and 0.3°. In some embodiments, at the twelfth theta @12) (300°), the first transition included angle α can be greater than 0.05°, 0.1°, 0.2°), or 0.3°. At a thirteenth theta θ₁₃ (330°), the first transition included angle α can be between 1.0° and 2.0°. In some embodiments, at the thirteenth theta θ₁₃ (330°), the first transition included angle α can be greater than 1.0°, 1.5°), or 2.0°.

The first transition rise 137 is the change in distance, measured perpendicular to the loft plane 15, from the first transition region perimeter 132 to the central region perimeter 126. A greater first transition rise 137 value indicates the transition region is increasing more than a lower first transition rise 137 value to provide more thickness in regions of the strike face 120 to normalize CT. At any given theta (θ) value, or theta (θ) range, the first transition rise 137 can be between 0.001 mm and 1.0 mm (0.000039 inch and 0.0393 inch). At a first theta θ₁ (0° or between a theta (θ) value between 345° and 15°), the first transition rise 137 can be between 0.46 mm and 0.58 mm (0.018 inch and 0.023 inch). In some embodiments, at the first theta θ₁ (0°), the run can be greater than 0.46 mm, 0.48 mm, 0.50 mm, 0.52 mm, 0.54 mm, 0.56 mm, or 0.58 mm. At a second theta θ₂ (30°), the first transition rise 137 can be between 0.4 mm and 0.5 mm (0.0157 inch and 0.0197 inch). In some embodiments, at the second theta θ₂ (30°), the first transition rise 137 can be greater than 0.40 mm, 0.42 mm, 0.44 mm, 0.46 mm, 0.48 mm, or 0.50 mm. At a third theta θ₃ (60°), the first transition rise 137 can be between 0.125 mm and 0.225 mm (0.0049 inch and 0.0089 inch). In some embodiments, at the third theta θ₃ (60°), the first transition rise 137 can be greater than 0.125 mm, 0.145 mm, 0.165 mm, 0.185 mm, 0.205 mm, or 0.225 mm. At a fourth theta θ₄ (90°), the first transition rise 137 can be between 0.02 mm and 0.03 mm (0.00079 inch and 0.0012 inch). In some embodiments, at the fourth theta θ₄ (90°), the first transition rise 137 can be greater than 0.020 mm, 0.022 mm, 0.024 mm, 0.026 mm, 0.028 mm, or 0.030 mm. At a fifth theta θ₅ (120°), the first transition rise 137 can be between 0.125 mm and 0.6 mm (0.0049 inch and 0.024 inch). In some embodiments, at the fifth theta θ₅ (120°), the first transition rise 137 can be between, 0.125 mm to 0.250 mm, 0.250 mm to 0.375 mm, 0.375 mm to 0.500 mm, and 0.500 mm to 0.600 mm. In some embodiments, at the fifth theta θ₅) (120°), the first transition rise 137 can be greater than 0.125 mm, 0.250 mm, 0.375 mm, 0.500 mm, or 0.600 mm. At a sixth theta θ₆ (150°), the first transition rise 137 can be between 0.3 mm and 0.9 mm (0.012 inch and 0.035 inch). In some embodiments, at the sixth theta θ₆ (150°), the first transition rise 137 can be between 0.30 mm to 0.40 mm, 0.40 to 0.50 mm, 0.50 to 0.60 mm, 0.60 to 0.70 mm, 0.70 to 0.80 mm, or 0.80 to 0.90 mm. In some embodiments, at the sixth theta θ₆ (150°), the first transition rise 137 can be greater than 0.30 mm, 0.40 mm, 0.50 mm, 0.60 mm, 0.70 mm, 0.80 mm, or 0.90 mm. At a seventh theta θ₇ (180°), the first transition rise 137 can be between 0.35 mm and 0.95 mm (0.014 inch and 0.037 inch). In some embodiments, at the seventh theta θ₇ (180°), the first transition rise 137 can be between 0.35 mm to 0.45 mm, 0.45 to 0.55 mm, 0.55 to 0.65 mm, 0.65 to 0.75 mm, 0.75 to 0.85 mm, or 0.85 to 0.95 mm. In some embodiments, at the seventh theta θ₇ (180°), the first transition rise 137 can be greater than 0.35 mm, 0.45 mm, 0.55 mm, 0.65 mm, 0.75 mm, 0.85 mm, or 0.95 mm. At an eighth theta θ₈ (210°), the first transition rise 137 can be between 0.3 mm and 0.8 mm (0.012 inch and 0.031 inch). In some embodiments, at the eighth theta θ₈ (210°), the first transition rise 137 can be between, 0.30 mm to 0.40 mm, 0.40 to 0.50 mm, 0.50 to 0.60 mm, 0.60 to 0.70 mm, 0.70 to 0.80 mm. In some embodiments, at the eighth theta θ₈ (210°), the first transition rise 137 can be greater than 0.30 mm, 0.40 mm, 0.50 mm, 0.60 mm, 0.70 mm, 0.80 mm. At a ninth theta θ₉ (240°), the first transition rise 137 can be between 0.05 mm and 0.35 mm (0.0019 inch and 0.0138 inch). In some embodiments, at the ninth theta θ₉ (240°), the first transition rise 137 can be between 0.05 mm and 0.15 mm, 0.15 mm and 0.25 mm, or 0.25 mm and 0.35 mm. In some embodiments, at the ninth theta θ₉ (240°), the first transition rise 137 can be greater than 0.05 mm, 0.15 mm, 0.20 mm, 0.25 mm, 0.30 mm, or 0.35 mm. At a tenth theta θ₁₀ (270°), the first transition rise 137 can be between 0.4 mm and 0.7 mm (0.016 inch and 0.028 inch). In some embodiments, at the tenth theta θ₁₀ (270°), the first transition rise 137 can be, 0.40 mm to 0.50 mm, 0.50 to 0.60 mm, or 0.60 to 0.70 mm. In some embodiments, at the tenth theta θ₁₀ (270°), the first transition rise 137 can be greater than 0.40 mm, 0.50 mm, 0.60 mm, or 0.70 mm. At an eleventh theta θ₁₁ (285°), the first transition rise 137 can be between 0.45 mm and 0.85 mm (0.018 inch and 0.033 inch). In some embodiments, at the eleventh theta θ₁₁ (285°), the first transition rise 137 can be between 0.45 m to 0.55 mm, 0.55 mm to 0.65 mm, 0.65 mm to 0.75 mm, or 0.75 mm to 0.85 mm. In some embodiments, at the eleventh theta θ₁₁ (285°), the first transition rise 137 can be greater than 0.45 mm, 0.50 mm, 0.55 mm, 0.60 mm, 0.65 mm, 0.70 mm, 0.75 mm, 0.80 mm, or 0.85 mm. At a twelfth theta θ₁₂ (300°), the first transition rise 137 can be between 0.2 mm and 0.35 mm (0.008 inch and 0.014 inch). In some embodiments, at the twelfth theta θ₁₂ (300°), the first transition rise 137 can be greater than 0.2 mm, 0.25 mm, 0.30 mm, or 0.35 mm. At a thirteenth theta θ₁₃ (330°), the first transition rise 137 can be between 0.25 mm and 0.4 mm (0.009 inch and 0.015 inch). In some embodiments, at the thirteenth theta θ₁₃ (330°), the first transition rise 137 can be greater than 0.25 mm, 0.30 mm, 0.35 mm, or 0.40 mm.

The first transition run 134 is the distance between a point on the central perimeter and a point on the first transition perimeter on a given imaginary ray at a given theta (θ) value projected onto the loft plane 15 and taken along the imaginary ray. At any given theta (θ) value or theta (θ) range, the first transition run 134 can be between 5 mm and 30 mm (0.197 inch and 1.181 inch). At a first theta θ₁ (0°), the first transition run 134 can be between 11 mm and 15 mm (0.433 inch and 0.590 inch). In some embodiments, at the first theta θ₁ (0°), the first transition run 134 can be greater than 11 mm, 12 mm, 13 mm, 14 mm, or 15. At a second theta θ₂ (30°), the first transition run 134 can be between 13 mm and 17 mm (0.512 inch and 0.670 inch). In some embodiments, at the second theta θ₂ (30°), the first transition run 134 can be greater than 13 mm, 14 mm, 15 mm, 16 mm, or 17 mm. At a third theta θ₃ (60°), the first transition run 134 can be between 15 mm and 20 mm (0.590 inch and 0.787 inch). In some embodiments, at the third theta θ₃ (60°), the first transition run 134 can be greater than 15 mm, 16 mm, 17 mm, 18 mm, 19 mm, or 20 mm. At a fourth theta θ₄ (90°), the first transition run 134 can be between 17 mm and 21 mm (0.669 inch and 0.826 inch). In some embodiments, at the fourth theta θ₄ (90°), the first transition run 134 can be greater than 17 mm, 18 mm, 19 mm, 20 mm, or 21 mm. At a fifth theta θ₈ (120°), the first transition run 134 can be between 11 mm and 19 mm (0.433 inch and 0.748 inch). In some embodiments, at the fifth theta θ₅ (120°), the first transition run 134 can be between 11 mm to 12 mm, 12 mm to 13 mm, 13 mm to 14 mm, 14 mm to 15 mm, 15 mm to 16 mm, 16 mm to 17 mm, 17 mm to 18 mm, or 18 mm to 19 mm. In some embodiments, at the fifth theta θ₅ (120°), the first transition run 134 can be greater than 11 mm, 12 mm, 13 mm, 14 mm, 15 mm, 16 mm, 17 mm, 18 mm, or 19 mm. At a sixth theta θ₆ (150°), the first transition run 134 can be between 7 mm and 16 mm (0.276 inch and 0.629 inch). In some embodiments, at the sixth theta θ₆ (150°), the first transition run 134 can be between 7 mm to 8 mm, 8 mm to 9 mm, 9 mm to 10 mm, 10 mm to 11 mm, 11 mm to 12 mm, 12 mm to 13 mm, 13 mm to 14 mm, 14 mm to 15 mm, or 15 mm to 16 mm. In some embodiments, at the sixth theta θ₆ (150°), the first transition run 134 can be greater than 7 mm, 8 mm, 9 mm, 10 mm, 11 mm, 12 mm, 13 mm, 14 mm, 15 mm, or 16 mm. At a seventh theta θ₇ (180°), the first transition run 134 can be between 6 mm and 14 mm (0.236 inch and 0.551 inch). In some embodiments, at the seventh theta θ₇ (180°), the first transition run 134 can be between 6 mm to 7 mm, 7 mm to 8 mm, 8 mm to 9 mm, 9 mm to 10 mm, 10 mm to 11 mm, 11 mm to 12 mm, 12 mm to 13 mm, or 13 mm to 14 mm. In some embodiments, at the seventh theta θ₇ (180°), the first transition run 134 can be greater than 6 mm, 7 mm, 8 mm, 9 mm, 10 mm, 11 mm, 12 mm, 13 mm, or 14 mm. At an eighth theta θ₈ (210°), the first transition run 134 can be between 7 mm and 16 mm (0.276 inch and 0.630 inch). In some embodiments, at the eighth theta θ₈ (210°), the first transition run 134 can be between 7 mm to 8 mm, 8 mm to 9 mm, 9 mm to 10 mm, 10 mm to 11 mm, 11 mm to 12 mm, 12 mm to 13 mm, 13 mm to 14 mm, 14 mm to 15 mm, or 15 mm to 16 mm. In some embodiments, at the eighth theta θ₈ (210°), the first transition run 134 can be greater than 7 mm, 8 mm, 9 mm, 10 mm, 11 mm, 12 mm, 13 mm, 14 mm, 15 mm, or 16 mm. At a ninth theta θ₉ (240°), the first transition run 134 can be between 14 mm and 20 mm (0.551 inch and 0.787 inch). In some embodiments, at the ninth theta θ₉ (240°), the first transition run 134 can be between 14 mm to 15 mm, 15 mm to 16 mm, 16 mm to 17 mm, 17 mm to 18 mm, 18 mm to 19 mm, or 19 mm to 20 mm. In some embodiments, at the ninth theta θ₉ (240°), the first transition run 134 can be greater than 14 mm, 15 mm, 16 mm, 17 mm, 18 mm, 19 mm, or 20 mm. At a tenth theta θ₁₀ (270°), the first transition run 134 can be between 21 mm and 27 mm (0.827 inch and 1.063 inches). In some embodiments, at the tenth theta θ₁₀ (270°), the first transition run 134 can be between 21 mm to 22 mm, 22 mm to 23 mm, 23 mm to 24 mm, 24 mm to 25 mm, 25 mm to 26 mm, or 26 mm to 27 mm. In some embodiments, at the tenth theta θ₁₀) (270°), the first transition run 134 can be greater than 21 mm, 22 mm, 23 mm, 24 mm, 25 mm, 26 mm, or 27 mm. At an eleventh theta θ₁₁ (285°), the first transition run 134 can be between 22 mm and 26 mm (0.866 inch and 1.024 inches). In some embodiments, at the eleventh theta θ₁₁) (285°), the first transition run 134 can be greater than 22 mm, 23 mm, 24 mm, 25 mm, or 26 mm. At a twelfth theta θ₁₂ (300°), the first transition run 134 can be between 18 mm and 22 mm (0.709 inch and 0.866 inch). In some embodiments, at the twelfth theta θ₁₂ (300°), the first transition run 134 can be greater than 18 mm, 19 mm, 20 mm, 21 mm, or 22 mm. At a thirteenth theta θ₁₃ (330°), the first transition run 134 can be between 12 mm and 16 mm (0.472 inch and 0.630 inch). In some embodiments, at the thirteenth theta θ₁₃ (330°), the first transition run 134 can be greater than 12 mm, 13 mm, 14 mm, 15 mm, or 16 mm.

The loft plane slope is the rise divided by the run and therefore reflects the change in distance from the first transition region perimeter 132 to the central region perimeter 126 on a given imaginary ray at a given theta (θ) value. A greater loft plane slope entails the first transition tapers quickly to reduce the amount of material along an imaginary ray thereby increasing the CT closer to the geometric center CT. A lesser loft plane slope entails the first transition tapers slower to increase the amount of material along an imaginary ray thereby decreasing the CT closer to the geometric center CT. Varying the loft plane slope between different imaginary rays normalizes CT across the strike face 120 as different strike face 120 regions can be targeted to have more thickness or less thickness depending on what is needed. At any given theta (θ) value or theta (θ) range, the loft plane slope can be between 0.001 and 0.15. At a first theta θ₁ (0°), the loft plane slope can be between 0.025 and 0.5. In some embodiments, at the first theta θ₁ (0°), the loft plane slope can be greater than X. At a second theta θ₂ (30°), the loft plane slope can be between 0.02 and 0.035 In some embodiments, at the second theta θ₂ (30°), the loft plane slope can be greater than X. At a third theta θ₃ (60°), the loft plane slope can be between 0.006 and 0.013. In some embodiments, at the third theta θ₃ (60°), the loft plane slope can be greater than X. At a fourth theta θ₄ (90°), the loft plane slope can be between 0.0011 and 0.0015 In some embodiments, at the fourth theta θ₄ (90°), the loft plane slope can be greater than X. At a fifth theta θ₈ (120°), the loft plane slope can be between 0.006 and 0.040. In some embodiments, at the fifth theta θ₈ (120°), the loft plane slope can be between 0.006 to 0.010, 0.010 to 0.015, 0.015 to 0.020, 0.020 to 0.025, 0.025 to 0.030, 0.030 to 0.035, or 0.035 to 0.040. In some embodiments, at the fifth theta θ₅ (120°), the loft plane slope can be greater than 0.006, 0.010, 0.015, 0.020, 0.025, 0.030, 0.035, or 0.040. At a sixth theta θ₆ (150°), the loft plane slope can be between 0.01 and 0.11. In some embodiments, at the sixth theta θ₆ (150°), the loft plane slope can be between 0.01 to 0.02, 0.02 to 0.03, 0.03 to 0.04, 0.04 to 0.05, 0.05 to 0.06, 0.06 to 0.07, 0.07 to 0.08, 0.08 to 0.09, 0.09 to 0.10, or 0.10 to 0.11. In some embodiments, at the sixth theta θ₆ (150°), the loft plane slope can be greater than 0.01, 0.02, 0.03, 0.04, 0.05, 0.06, 0.07, 0.08, 0.09, 0.10, or 0.11. At a seventh theta θ₇ (180°), the loft plane slope can be between 0.01 and 0.12. In some embodiments, at the seventh theta θ₇ (180°), the loft plane slope can be between 0.01 to 0.02, 0.02 to 0.03, 0.03 to 0.04, 0.04 to 0.05, 0.05 to 0.06, 0.06 to 0.07, 0.07 to 0.08, 0.08 to 0.09, 0.09 to 0.10, 0.10 to 0.11, or 0.11 to 0.12. In some embodiments, at the seventh theta θ₇ (180°), the loft plane slope can be greater than 0.01, 0.02, 0.03, 0.04, 0.05, 0.06, 0.07, 0.08, 0.09, 0.10, 0.11, or 0.12. At an eighth theta θ₈ (210°), the loft plane slope can be between 0.01 and 0.09. In some embodiments, at the eighth theta θ₈ (210°), the loft plane slope can be between 0.01 to 0.02, 0.02 to 0.03, 0.03 to 0.04, 0.04 to 0.05, 0.05 to 0.06, 0.06 to 0.07, 0.07 to 0.08, or 0.08 to 0.09. In some embodiments, at the eighth theta θ₈ (210°), the loft plane slope can be greater than 0.01, 0.02, 0.03, 0.04, 0.05, 0.06, 0.07, 0.08, or 0.09. At a ninth theta θ₉) (240°), the loft plane slope can be between 0.003 and 0.021. In some embodiments, at the ninth theta θ₉ (240°), the loft plane slope can be between 0.003 to 0.006, 0.006 to 0.009, 0.009 to 0.012, 0.012 to 0.015, 0.015 to 0.018, or 0.018 to 0.021. In some embodiments, at the ninth theta θ₉ (240°), the loft plane slope can be greater than 0.003, 0.006, 0.009, 0.012, 0.015, 0.018, or 0.021. At a tenth theta θ₁₀ (270°), the loft plane slope can be between 0.015 and 0.03. In some embodiments, at the tenth theta θ₁₀ (270°), the loft plane slope can be between 0.015 to 0.018, 0.018 to 0.021, 0.021 to 0.024, 0.024 to 0.027, or 0.027 to 0.030. In some embodiments, at the tenth theta θ₁₀ (270°), the loft plane slope can be greater than 0.015, 0.018, 0.021, 0.024, 0.027, or 0.030. At an eleventh theta θ₁₁ (285°), the loft plane slope can be between 0.015 and 0.040. In some embodiments, at the eleventh theta θ₁₁ (285°), the loft plane slope can be between 0.015 to 0.018, 0.018 to 0.021, 0.021 to 0.024, 0.024 to 0.027, 0.027 to 0.030, 0.030 to 0.033, 0.033 to 0.036, or 0.036 to 0.040. In some embodiments, at the eleventh theta θ₁₁ (285°), the loft plane slope can be greater than 0.015, 0.018, 0.021, 0.024, 0.027, 0.030, 0.033, 0.036, or 0.040. At a twelfth theta θ₁₂ (300°), the loft plane slope can be between 0.010 and 0.020. In some embodiments, at the twelfth theta θ₁₂ (300°), the loft plane slope can be greater than 0.010, 0.011, 0.012, 0.013, 0.014, 0.015, 0.016, 0.017, 0.018, 0.019, or 0.020. At a thirteenth theta θ₁₃) (330°), the loft plane slope can be between 0.015 and 0.03. In some embodiments, at the thirteenth theta θ₁₃ (330°), the loft plane slope can be between 0.015 to 0.018, 0.018 to 0.021, 0.021 to 0.024, 0.024 to 0.027, or 0.027 to 0.030. In some embodiments, at the thirteenth theta θ₁₃ (330°), the loft plane slope can be greater than 0.015, 0.018, 0.021, 0.024, 0.027, or 0.030.

The first transition thickness change 139 is measured tangential to the strike face outer surface 121, from the first transition region perimeter 132 to the central region perimeter 126 on a given imaginary ray at a given theta (θ) value. The first transition thickness change 139 reflects how much thickness is located along the first transition region perimeter 132. A larger first transition thickness change 139 entails there is less thickness at the first transition region perimeter 132 thereby increasing CT closer to the face geometric center FC CT. A smaller first transition thickness change 139 entails there is more thickness at the first transition region perimeter 132 thereby decreasing CT closer to the face geometric center FC CT. At any given theta (θ) value or theta (θ) range, the first transition thickness change 139 can be between 0.75 mm and 1.75 mm (0.029 inch and 0.069 inch). At a first theta θ₁ (0°), the first transition thickness change 139 can be between 0.5 mm and 1.5 mm (0.019 inch and 0.059 inch). In some embodiments, at the first theta θ₁ (0°), the first transition thickness change 139 can be between 0.5 mm to 0.6 mm, 0.6 mm to 0.7 mm, 0.7 mm to 0.8 mm, 0.8 mm to 0.9 mm, 0.9 mm to 1.0 mm, 1.0 mm to 1.1 mm, 1.1 mm to 1.2 mm, 1.2 mm to 1.3 mm, 1.3 mm to 1.4 mm, or 1.4 mm to 1.5 mm. In some embodiments, at the first theta θ₁ (0°), the first transition thickness change 139 can be greater than 0.5 mm, 0.6 mm, 0.7 mm, 0.8 mm, 0.9 mm, 1.0 mm, 1.1 mm, 1.2 mm, 1.3 mm, 1.4 mm, or 1.5 mm. At a second theta θ₂ (30°), a third theta θ₃ (60°), a fourth theta θ₄) (90°), a fifth theta θ₅ (120°), an eighth theta θ₈ (210°), a ninth theta θ₉ (240°), and/or a tenth theta θ₁₀ (270°), the first transition thickness change 139 can be between 1.15 mm and 1.5 mm (0.045 inch and 0.059 inch). In some embodiments, at the second theta θ₂ (30°), the third theta θ₃ (60°), the fourth theta θ₄ (90°), the fifth theta θ₈ (120°), the eighth theta θ₈ (210°), the ninth theta θ₉ (240°), and/or the tenth theta θ₁₀ (270° the first transition thickness change 139 can be greater than 1.15 mm, 1.20 mm, 1.25 mm, 1.30 mm, 1.35 mm, 1.40 mm, 1.45 mm, or 1.50 mm. At a sixth theta θ₆ (150° and/or a seventh theta θ₇ (180°), the first transition thickness change 139 can be between 1.0 mm and 1.3 mm (0.039 inch and 0.051 inch). In some embodiments, at the sixth theta θ₆ (150° and/or the seventh theta θ₇ (180°), the first transition thickness change 139 can be greater than 1.0 mm, 1.1 mm, 1.2 mm, or 1.3 mm. At an eleventh theta θ₁₁ (285°), the first transition thickness change 139 can be between 0.8 mm and 1.3 mm (0.031 inch and 0.051 inch). In some embodiments, at the eleventh theta θ₁₁ (285°), the first transition thickness change 139 can be greater than 0.8 mm, 0.9 mm, 1.0 mm, 1.1 mm, 1.2 mm, or 1.3 mm. At a twelfth theta θ₁₂ (300°), the first transition thickness change 139 can be between 0.7 mm and 1.2 mm (0.028 inch and 0.047 inch). In some embodiments, at the twelfth theta @12) (300°), the first transition thickness change 139 can be between 0.7 mm to 0.8 mm, 0.8 mm to 0.9 mm, 0.9 mm to 1.0 mm, 1.0 mm to 1.1 mm, or 1.1 mm to 1.2 mm. In some embodiments, at the twelfth theta θ₁₂ (300°), the first transition thickness change 139 can be greater than 0.7 mm, 0.8 mm, 0.9 mm, 1.0 mm, 1.1 mm, or 1.2 mm. At a thirteenth theta θ₁₃ (330°), the first transition thickness change 139 can be between 0.8 mm and 1.2 mm (0.031 inch and 0.047 inch). In some embodiments, at the thirteenth theta θ₁₃ (330°), the first transition thickness change 139 can be between 0.8 mm to 0.9 mm, 0.9 mm to 1.0 mm, 1.0 mm to 1.1 mm, or 1.1 mm to 1.2 mm. In some embodiments, at the thirteenth theta θ₁₃ (330°), the first transition thickness change 139 can be greater than 0.8 mm, 0.9 mm, 1.0 mm, 1.1 mm, or 1.2 mm.

The thickness slope is the slope of the first transition calculated by taking the first transition thickness change 139 between a point on the central perimeter and a point on the first transition perimeter on a given imaginary ray at a given theta (θ) value. and dividing it by the run. A greater thickness slope entails the first transition tapers quickly to reduce the amount of material along an imaginary ray thereby increasing the CT closer to the geometric center CT. A lesser 1 thickness slope entails the first transition tapers slower to increase the amount of material along an imaginary ray thereby decreasing the CT closer to the geometric center CT. Varying the thickness slope between different imaginary rays normalizes CT across the strike face 120 as different strike face 120 regions can be targeted to have more thickness or less thickness depending on what is needed. At any given theta (θ) value or theta (θ) range, the thickness slope can be between 0.02 and 17. At a first theta θ₁ (0° and/or a second theta θ₂ (30°), the thickness slope can be between 0.06 and 0.10. In some embodiments, at the first theta θ₁ (0° and/or the second theta θ₂ (30°), the thickness slope can be greater than 0.06, 0.07, 0.08, 0.09, or 0.10. At a third theta θ₃ (60°), the thickness slope can be between 0.05 and 0.08. In some embodiments, at the third theta θ₃ (60°), the thickness slope can be greater than 0.05, 0.06, 0.07, or 0.08. At a fourth theta θ₄ (90°), the thickness slope can be between 0.04 and 0.08. In some embodiments, at the fourth theta θ₄ (90°), the thickness slope can be greater than 0.04, 0.05, 0.06, 0.07, or 0.08. At a fifth theta θ₅ (120°), the thickness slope can be between 0.05 and 0.11. In some embodiments, at the fifth theta θ₅ (120°), the thickness slope can be 0.05 to 0.06, 0.06 to 0.07, 0.07 to 0.08, 0.08 to 0.09, 0.09 to 0.10, or 0.10 to 0.11 In some embodiments, at the fifth theta θ₅) (120°), the thickness slope can be greater than 0.05, 0.06, 0.07, 0.08, 0.09, 0.10, or 0.11. At a sixth theta θ₆ (150°), the thickness slope can be between 0.06 and 0.16. In some embodiments, at the sixth theta θ₆ (150°), the thickness slope can be between 0.06 to 0.07, 0.07 to 0.08, 0.08 to 0.09, 0.09 to 0.10, 0.10 to 0.11, 0.11 to 0.12, 0.12 to 0.13, 0.13 to 0.14, 0.14 to 0.15, or 0.15 to 0.16. In some embodiments, at the sixth theta θ₆ (150°), the thickness slope can be greater than 0.06, 0.07, 0.08, 0.09, 0.10, 0.11, 0.12, 0.13, 0.14, 0.15, or 0.16. At a seventh theta θ₇ (180°), the thickness slope can be between 0.07 and 0.17. In some embodiments, at the seventh theta θ₇) (180°), the thickness slope can be between 0.07 to 0.08, 0.08 to 0.09, 0.09 to 0.10, 0.10 to 0.11, 0.11 to 0.12, 0.12 to 0.13, 0.13 to 0.14, 0.14 to 0.15, 0.15 to 0.16, or 0.16 to 0.17. In some embodiments, at the seventh theta θ₇ (180°), the thickness slope can be greater than 0.07, 0.08, 0.09, 0.10, 0.11, 0.12, 0.13, 0.14, 0.15, 0.16, or 0.17. At an eighth theta θ₈ (210°), the thickness slope can be between 0.06 and 0.16. In some embodiments, at the eighth theta θ₈ (210°), the thickness slope can be between 0.06 to 0.07, 0.07 to 0.08, 0.08 to 0.09, 0.09 to 0.10, 0.10 to 0.11, 0.11 to 0.12, 0.12 to 0.13, 0.13 to 0.14, 0.14 to 0.15, or 0.15 to 0.16. In some embodiments, at the eighth theta θ₈ (210°), the thickness slope can be greater than 0.06, 0.07, 0.08, 0.09, 0.10, 0.11, 0.12, 0.13, 0.14, 0.15, or 0.16. At a ninth theta θ₉ (240°), the thickness slope can be between 0.04 and 0.10. In some embodiments, at the ninth theta θ₉ (240°), the thickness slope can be between 0.04 to 0.05, 0.05 to 0.06, 0.06 to 0.07, 0.07 to 0.08, 0.08 to 0.09, or 0.09 to 0.10. In some embodiments, at the ninth theta θ₉ (240°), the thickness slope can be greater than 0.04, 0.05, 0.06, 0.07, 0.08, 0.09, or 0.10. At a tenth theta θ₁₀ (270°), the thickness slope can be between 0.03 and 0.07. In some embodiments, at the tenth theta θ₁₀ (270°), the thickness slope can be greater than 0.03, 0.04, 0.05, 0.06, or 0.07. At an eleventh theta θ₁₁ (285° and/or a twelfth theta θ₁₂ (300°), the thickness slope can be between 0.02 and 0.07. In some embodiments, at the eleventh theta θ₁₁ (285° and/or the twelfth theta θ₁₂ (300°), the thickness slope can be greater than 0.02, 0.03, 0.04, 0.05, 0.06, or 0.07. At a thirteenth theta θ₁₃ (330°), the thickness slope can be between 0.05 and 0.09. In some embodiments, at the thirteenth theta θ₁₃ (330°), the thickness slope can be greater than 0.05, 0.06, 0.07, 0.08, or 0.09.

Any of the specific theta values disclosed above can be rewritten as a range plus or minus 15°. The first theta θ₁ (0° can alternatively be a theta value between 345° and 15°; the second theta θ₂ (30° can alternatively be a theta value between 15° and 45°; the third theta θ₃ (60° can alternatively be a theta value between 45° and 75°; the fourth theta θ₄ (90° can alternatively be a theta value between 75° and 105°; the fifth theta θ₈ (120° can alternatively be a theta value between 105° and 135°; the sixth theta θ₆ (150° can alternatively be a theta value between 135° and 165°; the seventh theta θ₇ (180° can alternatively be a theta value between 165° and 195°; the eighth theta θ₈ (210° can alternatively be a theta value between 195° and 225°; the ninth theta θ₉ (240° can alternatively be a theta value between 225° and 255°; the tenth theta θ₁₀) (270° can alternatively be a theta value between 255° and 285°; the eleventh theta θ₁₁ (285° can alternatively be a theta value between 270° and 300°; the twelfth theta 12) (300° can alternatively be a theta value between 285° and 315°; and the thirteenth theta θ₁₃ (330° can alternatively be a theta value between 315° and 345°.

VI. Measurement Relationships

In some embodiments the measurements described herein along a first imaginary ray at a first theta (θ) value have relationships with measurements along another imaginary ray at a different theta (θ) value and/or values to provide a normalized CT across the strike face 120. Further, the golf clubs described herein can comprise the following thickness relationships, the central region 124 thickness is greater than an intermediate region 136 thickness, a first transition region 130 thickness, a second transition region 140 thickness, and an outer region 146 thickness. The outer region 146 thickness is greater than the intermediate region 136 thickness. These thickness relationships normalize CT across the strike face.

In an exemplary embodiment, a golf club head 100 can comprise measurements that decrease CT in the upper heel region of the strike face. The golf club head 100 can comprise a thickness slope less than 0.06, a first transition run 134 greater than 20 mm, a theoretical first transition length 133a greater than 21 mm, and a first transition length 135 greater than 20 mm between theta (θ) values of 260° to 310°), as illustrated in FIG. 7. These measurements reflect that the first transition region extends greater into an upper heel region of the strike face, than any other region of the strike face 120. This decreases the CT in the upper heel region of the strike face 120 to normalize CT across the strike face. In some embodiments, the thickness slope between theta (θ) values of 260° to 310° is less than the thickness slope between theta (θ) values of 0° to 259° and 311° to 360°. In some embodiments, the first transition run 134 between theta (θ) values of 260° to 310° is greater than the first transition run between theta (θ) values of 0° to 259° and 311° to 360°. In some embodiments, the theoretical first transition length 133a between theta (θ) values of 260° to 310° is greater than the first theoretical transition length 133a between theta (θ) values of 0° to 259° and 311° to 360°. In some embodiments, the first transition length 135 between theta (θ) values of 260° to 310° is greater than the first transition length 135 between theta (θ) values of 0° to 259° and 311° to 360°.

In another exemplary embodiment, a golf club head 300 can comprise a central region 324, a central region perimeter 326, a first transition region 330, a first transition region perimeter 332, an intermediate region 336, an intermediate region perimeter 338, a second transition region 340, a second transition perimeter 342, an outer region 346, an outer region perimeter 348, an inner strike face surface perimeter 323b, and a theoretical first transition perimeter 333b.

The golf club head 300 can comprise measurements that decrease CT in the upper heel region of the strike face. The golf club head 300 comprises a strike face VFT comprising a thickness slope less than 0.06, a first transition run 134 greater than 20 mm, a theoretical first transition length 133a greater than 21 mm, and a first transition length 135 greater than 20 mm between theta (θ) values of 260 to 310, as illustrated in FIG. 22. These measurements reflect that the first transition region extends greater into an upper heel region of the strike face, than any other region of the strike face 120. This decreases the CT in the upper heel region of the strike face to normalize CT across the strike face 120. In some embodiments, the thickness slope between theta (θ) values of 260° to 310° is less than the thickness slope between theta (θ) values of 0° to 259° and 311° to 360°. In some embodiments, the first transition run 134 between theta (θ) values of 260° to 310° is greater than the first transition run between theta (θ) values of 0° to 259° and 311° to 360°. In some embodiments, the theoretical first transition length 133a between theta (θ) values of 260° to 310° is greater than the first theoretical transition length 133a between theta (θ) values of 0° to 259° and 311° to 360°. In some embodiments, the first transition length 135 between theta (θ) values of 260° to 310° is greater than the first transition length 135 between theta (θ) values of 0° to 259° and 311° to 360°.

The golf club head 300 can comprise measurements that increase CT in the sole region of the strike face. The golf club head 300 can also comprise a thickness slope greater than 0.12, or in some embodiments greater than 0.15, a first transition included angle α greater than 4°), and in some embodiments greater than 6°), a first transition run 134 less than 10 mm, and a first transition length 135 less than 10.5 mm between theta (θ) values of 140° to 220°), or in some embodiments, between theta (θ) values of 160° and 200°. These measurements reflect that the first transition region extends less into the sole region of the strike face, than any other region of the strike face. This increases the CT in the sole region of the strike face by decreasing the strike face thickness, thereby normalizing CT across the strike face. In some embodiments, the thickness slope between theta (0) values of 140° to 220° is greater than thickness slope between theta (θ) values of 0° to 140° and 220° to 360°. In some embodiments, the thickness slope between theta (θ) values of 160° to 200° is greater than the thickness slope between theta (θ) values of 0° to 160° and 200° to 360°. In some embodiments, the first transition included angle between theta (θ) values of 140° to 220° is greater than the first transition included angle α between theta (θ) values of 0° to 140° and 220° to 360°. In some embodiments, the first transition included angle α between theta (θ) values of 160° to 200° is greater than the first transition included angle α between theta (θ) values of 0° to 160° and 200° to 360°. In some embodiments, the first transition run (measured the same as the first transition run 134) between theta (θ) values of 140° to 220° is less than the first transition between theta (θ) values of 0° to 140° and 220° to 360°. In some embodiments, the first transition between theta (θ) values of 160° to 200° is less than the first transition between theta (θ) values of 0° to 160° and 200° to 360°. In some embodiments, the first transition length (measured the same as the first transition length 135) between theta (θ) values of 140° to 220° is less than the first transition length between theta (θ) values of 0° to 140° and 220° to 360°. In some embodiments, the first transition length between theta (θ) values of 160° to 200° is less than the first transition length between theta (θ) values of 0° to 160° and 200° to 360°.

VII. Second Transition Region

The second transition region 140 extends at least partially around perimeters of the intermediate region 136 and the first transition region 130. The second transition region 140 increases in thickness from the first transition region 130 and the intermediate region 136, to the outer region 146. In some embodiments, the second transition region perimeter 142 can define a weld line or an attachment point for a face plate 105. The face plate 105 can be welded to a frame 150. In other embodiments, the face plate 105 can be made from a composite material, such as multiple plies of a fiber reinforced polymer and mechanically attached to the frame 150.

In embodiments wherein the second transition region comprises a weld, the second transition region 140 can comprise a thicker portion as the result of the weld. The thicker portion may provide additional strength at the weld line, better securing the face plate 105 to the frame 150. In some embodiments, the second transition region 140 maximum thickness may be between 1 mm and 31 mm (0.039 inch and 1.220 inches). In other embodiments, the second transition region 140 maximum thickness may be between 1 mm and 4 mm (0.039 inch and 0.157 inch), 4 mm and 7 mm (0.157 inch and 0.276 inch), 7 mm and 10 mm (0.276 inch and 0.394 inch), 10 mm and 13 mm (0.394 inch and 0.512 inch), 13 mm and 16 mm (0.512 inch and 0.630 inch), 16 mm and 19 mm (0.630 inch and 0.748 inch), 19 mm and 22 mm (0.748 inch and 0.866 inch), 22 mm and 25 mm (0.866 inch and 0.984 inch), 25 mm and 28 mm (0.984 inch and 1.102 inches), or 28 mm and 31 mm (1.102 inches and 1.220 inches). In some other instances, the second transition region 140 maximum thickness may be between 0.2 mm and 1.0 mm (0.008 inch and 0.039 inch) thicker than the outer region 146. In other embodiments, the second transition region 140 maximum thickness may be between 0.2 mm and 0.4 mm (0.008 inch and 0.016 inch), 0.4 and 0.6 mm (0.016 inch and 0.024 inch), 0.6 mm and 0.8 mm (0.024 inch and 0.031 inch), or 0.8 mm and 1.0 mm (0.031 inch and 0.039 inch) thicker than the outer region 146.

The second transition region distance 144 is the width of the second transition region 140. This is further defined as the distance between the first transition region perimeter 132 to the beginning of the outer region 146 or the intermediate region perimeter 138 to the beginning of the outer region 146, whichever is applicable. The second transition region distance 144 may be constant length or variable length. In some embodiments, the second transition region distance 144 is between 2 mm and 12 mm (0.079 inch and 0.472 inch). In other embodiments, the second transition region distance 144 is between 2 mm and 4 mm (0.079 inch and 0.157 inch), 4 mm and 6 mm (0.157 inch and 0.236 inch), 6 mm and 8 mm (0.236 inch and 0.315 inch), 8 mm and 10 mm (0.315 inch and 0.394 inch), or 10 mm and 12 mm (0.394 inch and 0.472 inch).

A. Percent Second Transition Region Surrounds the First Transition Region

In some embodiments, the second transition region 140 may partially or fully surround the first transition region 130. The second transition region 140 may surround between 25% and 100% of the first transition region 130. In some embodiments, the second transition region 140 may surround between 25% and 30%, between 30% and 35%, between 35% and 40%, between 40% and 45%, between 45% and 50%, between 50% and 55%, between 55% and 60%, between 60% and 65%, between 65% and 70%, between 70% and 75%, between 75% and 80%, between 80% and 85%, between 85% and 90%, between 90% and 95%, or between 95% and 100% of the first transition region 130.

B. Percent Second Transition Region Surrounds the Intermediate Region

In some embodiments, the second transition region 140 may partially or fully surround the intermediate region 136. The second transition region 140 may surround between 25% and 99% of the intermediate region 136. In some embodiments, the second transition region 140 may surround between 25% and 30%, between 30% and 35%, between 35% and 40%, between 40% and 45%, between 45% and 50%, between 50% and 55%, between 55% and 60%, between 60% and 65%, between 65% and 70%, between 70% and 75%, between 75% and 80%, between 80% and 85%, between 85% and 90%, between 90% and 95%, or between 95% and 99% of the intermediate region 136.

VIII. Intersection Points of Transition Perimeter Intermediate Perimeter and Second Transition

In some embodiments, the first transition region perimeter 132, the intermediate region perimeter 138, and the second transition region 140, can intersect to form an intersection point 180 which can define where the thinnest region of the strike face 120, begins thereby normalizing CT by increasing the CT value at this location closer to the geometric center CT. The first transition region perimeter 132 can form an angle with the intermediate region perimeter 138. In some embodiments the first transition region perimeter 132, the intermediate region perimeter 138, and the second transition region 140 intersect at theta (θ) values between 0° and 360°. In some embodiments the first transition region perimeter 132, the intermediate region perimeter 138, and the second transition region 140 intersect at theta (θ) values between 25° and 35°, 125° and 135°), and/or 275° and 290°. In some embodiments the first transition region perimeter 132, the intermediate region perimeter 138, and the second transition region 140 intersect at theta (θ) values between 10° and 30° and/or 265° and 280°.

IX. Outer Region

The outer region 146 has a constant a constant thickness between the thickness of the intermediate region 136 and thickness of the central region 124 to provide structural support to the thinner regions of the strike face 120. The outer region 146 surrounds the second transition region 140. The outer region 146 extends from the second transition region perimeter 142 to the strike face inner perimeter 123b. The outer region 146 further comprises an outer region perimeter 148 that is the same as the strike face inner perimeter 123b. In some embodiments, the outer region 146 can extend past the strike face outer perimeter 123a as projected onto the XY plane.

X. Open Hosel

In some embodiments, the golf club head 100 can comprise a hosel 111 structure that is open to the interior cavity 114 to save mass and lower the CG of the golf club head 100. Removing the structure from the hosel 111 removes structural support to the strike face compared to a conventional club head comprising a hosel bore extending from the crown 106 to the sole 108. Conventional club heads then have a hosel component that contacts and supports the face in the heel region. This lowers CT in the heel as the face cannot flex as greatly. The lack of support structure to the strike face 120 in the open hosel 111 design increases the CT in the high heel due to the face being able to flex more, compared to the conventional club head. More flexure results in a spring-like effect that can increase CT above conforming values. Therefore, extending the first transition region 130 into the high heel decreases the spring-like effect, and accordingly decreases the CT to a value closer to the CT at the geometric face center FC normalizes the CT across the strike face 120.

XI. Central Region Geometric Center/First Transition Region Geometric Center Relationship to Face Center

Alternatively, the VFT can be characterized by the relationship between the central region geometric center 128 and the first transition region geometric center 131 relative to the face center FC. In these VFT designs, the central region 124 and/or the first transition region 130 may be shifted or extended into various directions, thereby shifting its position relative to the rest of the face. This offset may be compared to the face center to quantify the shifting of these components. Generally, the first transition region geometric center 131 is based on the area contained within the theoretical first transition region perimeter 133b (described above). All aspects of a golf club structure affect CT value. Due to this, shifting the VFT regions aid in reducing “hot spots” and increasing “dead spots” to normalize CT across the face. For instance, in an open hosel 111 design, a “hot spot” in the high heel region may require extending and/or shifting the first transition region 130 further into said region.

The central region 124 may be shifted to encompass the largest CT values near the face center. This shift is quantified by comparing the relative position of the central region geometric center 128 to the face center FC. Generally, the direction that the central region 124 is shifted corresponds to reducing CT in that region. For instance, if a hot spot is found towards the heel 104, the central region 124 may be shifted in the heel-ward direction to reduce CT in the heel 104. This will typically lead to a CT increase towards the toe 102. In some embodiments the central region geometric center 128 may be offset between −10 mm and 10 mm (−0.394 inch and 0.394 inch) from the face center FC in the X-direction. In other embodiments the central region 124 may be offset from the face center in the X-direction between −10 mm and −9 mm (−0.394 inch and −0.354 inch), −9 mm and −8 mm (−0.354 inch and −0.315 inch), −8 mm and −7 mm (−0.315 inch and −0.276 inch), −7 mm and −6 mm (−0.276 inch and −0.236 inch), −6 mm and −5 mm (−0.236 inch and −0.197 inch), −5 mm and −4 mm (−0.197 inch and −0.157 inch), −4 mm and −3 mm (−0.157 inch and −0.118 inch), −3 mm and −2 mm (−0.118 inch and −0.079 inch), −2 mm and −1 mm (−0.079 inch and −0.039 inch), −1 mm and 0 mm (−0.039 inch and 0 inch), 0 mm and 1 mm (0 inch and 0.039 inch), 1 mm and 2 mm (0.039 inch and 0.079 inch), 2 mm and 3 mm (0.079 inch and 0.118 inch), 3 mm and 4 mm (0.118 inch and 0.157 inch), 4 mm and 5 mm (0.157 inch and 0.197 inch), 5 mm and 6 mm (0.197 inch and 0.236 inch), 6 mm and 7 mm (0.236 inch and 0.276 inch), 7 mm and 8 mm (0.276 inch and 0.315 inch), 8 mm and 9 mm (0.315 inch and 0.354 inch), or 9 mm and 10 (0.354 inch and 394 inch).

Additionally, the central region 124 may also be shifted in the Y-direction relative to the face center to in the upper portion of the club face, while increasing CT in the lower portion of the club face. In some embodiments the central region 124 shift in the Y-direction may be between −6 mm and 6 mm (−0.236 inch and 0.236 inch) from the face center. In other embodiments, the central region 124 may may be offset from the face center in the Y-direction between −6 mm and −5 mm (−0.236 inch and −0.197 inch), −5 mm and −4 mm (−0.197 inch and −0.157 inch), −4 mm and −3 mm (−0.157 inch and −0.118 inch), −3 mm and −2 mm (−0.118 inch and −0.079 inch), −2 mm and −1 mm (−0.079 inch and −0.039 inch), −1 mm and 0 mm (−0.039 inch and 0 inch), 0 mm and 1 mm (0 inch and 0.039 inch), 1 mm and 2 mm (0.039 inch and 0.079 inch), 2 mm and 3 mm (0.079 inch and 0.118 inch), 3 mm and 4 mm (0.118 inch and 0.157 inch), 4 mm and 5 mm (0.157 inch and 0.197 inch), or 5 mm and 6 mm (0.197 inch and 0.236 inch).

The first transition region 130 may be extended, truncated, or shifted in various ways to achieve the desired normalized CT across the face. The first transition region shift may be represented by the first transition region geometric center 131 location relative to the face center FC. Similar to the central region 124, shifting the first transition region 130, measured by its geometric center, can reduce CT in the direction it is shifted. In some embodiments, the first transition region geometric center 131 location may be shifted in the X-direction, relative to the face center, between −10 mm and 10 mm (−0.394 inch and 0.394 inch). In other embodiments, the first transition region geometric center 131 may be shifted in the X-direction, relative to the face center, between −10 mm and −9 mm (−0.394 inch and −0.354 inch), −9 mm and −8 mm (−0.354 inch and −0.315 inch), −8 mm and −7 mm (−0.315 inch and −0.276 inch), −7 mm and −6 mm (−0.276 inch and −0.236 inch), −6 mm and −5 mm (−0.236 inch and −0.197 inch), −5 mm and −4 mm (−0.197 inch and −0.157 inch), −4 mm and −3 mm (−0.157 inch and −0.118 inch), −3 mm and −2 mm (−0.118 inch and −0.079 inch), −2 mm and −1 mm (−0.079 inch and −0.039 inch), −1 mm and 0 mm (−0.039 inch and 0 inch), 0 mm and 1 mm (0 inch and 0.039 inch), 1 mm and 2 mm (0.039 inch and 0.079 inch), 2 mm and 3 mm (0.079 inch and 0.118 inch), 3 mm and 4 mm (0.118 inch and 0.157 inch), 4 mm and 5 mm (0.157 inch and 0.197 inch), 5 mm and 6 mm (0.197 inch and 0.236 inch), 6 mm and 7 mm (0.236 inch and 0.276 inch), 7 mm and 8 mm (0.276 inch and 0.315 inch), 8 mm and 9 mm (0.315 inch and 0.354 inch), or 9 mm and 10 (0.354 inch and 394 inch).

Additionally, the first transition region 130 may also be shifted in the Y-direction relative to the face center FC. In some embodiments the first transitional region shift in the Y-direction may be between −10 mm and 10 mm (−0.394 inch and 0.394 inch) from the face center. In other embodiments, the first transition region geometric center 131 may be shifted in the Y-direction, relative to the face center, between −10 mm and −9 mm (−0.394 inch and −0.354 inch), −9 mm and −8 mm (−0.354 inch and −0.315 inch), −8 mm and −7 mm (−0.315 inch and −0.276 inch), −7 mm and −6 mm (−0.276 inch and −0.236 inch), −6 mm and −5 mm (−0.236 inch and −0.197 inch), −5 mm and −4 mm (−0.197 inch and −0.157 inch), −4 mm and −3 mm (−0.157 inch and −0.118 inch), −3 mm and −2 mm (−0.118 inch and −0.079 inch), −2 mm and −1 mm (−0.079 inch and −0.039 inch), −1 mm and 0 mm (−0.039 inch and 0 inch), 0 mm and 1 mm (0 inch and 0.039 inch), 1 mm and 2 mm (0.039 inch and 0.079 inch), 2 mm and 3 mm (0.079 inch and 0.118 inch), 3 mm and 4 mm (0.118 inch and 0.157 inch), 4 mm and 5 mm (0.157 inch and 0.197 inch), 5 mm and 6 mm (0.197 inch and 0.236 inch), 6 mm and 7 mm (0.236 inch and 0.276 inch), 7 mm and 8 mm (0.276 inch and 0.315 inch), 8 mm and 9 mm (0.315 inch and 0.354 inch), or 9 mm and 10 (0.354 inch and 394 inch).

XII. Central Region Geometric Center to First Transition Region Geometric Center

The VFT design may also be represented as the offset of the central region geometric center 128 to the first transition region geometric center 131. This may be offset in both the X and Y-direction and represents the position of the central region 124 related to the first transition region 130. The central region 124 is generally located in a position on the face that would experience the highest CT values, due to a larger spring-like effect near the center of the face. Thus, the central region geometric center 128 will be near the face center. In certain embodiments, first transition region geometric center 131 may be in a similar position as the central region geometric center 128. In other embodiments, the first transition region geometric center 131 being shifted away from the central region geometric center 128 may signify a change in symmetry of the first transition region 130. For instance, in an open hosel 111 design, the sole-ward portion of the face may have a lower CT value and the high heel portion of the face may experience a non-conforming, high CT value. In this case, shortening the length of the first transition region 130 in the sole-ward side and extending the first transition region 130 length in the high heel portion will help normalize CT across the face. This adjustment will result in a first transition region geometric center 131 that is located crown-ward and heel-ward of the central region geometric center 128.

The offset between the central region geometric center 128 and the first transition region geometric center 131 may be measured in the X and Y-direction. In some embodiments the first transition region geometric center 131 may be offset from the central region geometric center 128 in the X-direction by −5 mm to 5 mm (−0.197 inch to 0.197 inch). In other embodiments, the first transition region geometric center 131 may be offset from the central region geometric center 128, in the X-direction, by −5 mm to −4 mm (−0.197 inch to −0.157 inch), −4 mm to −3 mm (−0.157 inch to −0.118 inch), −3 mm to −2 mm (−0.118 inch to −0.079 inch), −2 mm to −1 mm (−0.079 inch to −0.039 inch), −1 mm to 0 mm (−0.039 inch to 0 inch), 0 mm to 1 mm (0 inch to 0.039 inch), 1 mm to 2 mm (0.039 inch to 0.079 inch), 2 mm to 3 mm (0.079 inch to 0.118 inch), 3 mm to 4 mm (0.118 inch to 0.157 inch), or 4 mm to 5 mm (0.157 inch to 0.197 inch).

Additionally, Y-direction shifts may show an extended or shrunk upper or lower first transition region 130. The relationship generally shows how long or short the first transition region 130 extends in a crown-ward or sole-ward direction. The offset between the first transition region geometric center 131 and the central region geometric center 128, in the Y-direction, may be between −6 mm and 6 mm (−0.236 inch and 0.236 inch). In other embodiments, the first transition region geometric center 131 and the central region geometric center 128, in the Y-direction, may be between −6 mm and −5 mm (−0.236 inch and −0.197 inch), −5 mm and −4 mm (−0.197 inch and −0.157 inch), −4 mm and −3 mm (−0.157 inch and −0.118 inch), −3 mm and −2 mm (−0.118 inch and −0.079 inch), −2 mm and −1 mm (−0.079 inch and −0.039 inch), −1 mm and 0 mm (−0.039 inch and 0 inch), 0 mm and 1 mm (0 inch and 0.039 inch), 1 mm and 2 mm (0.039 inch and 0.079 inch), 2 mm and 3 mm (0.079 inch and 0.118 inch), 3 mm and 4 mm (0.118 inch and 0.157 inch), 4 mm and 5 mm (0.157 inch and 0.197 inch), or 5 mm and 6 mm (0.197 inch and 0.236 inch).

XIII. Face plate CG to Face Center

Due to the variable face thickness, the CG of face plate 105 may not line up with the face center. Instead, it may be offset from the face center in an X, Y, and/or Z direction. This generally shows how the VFT can be used to damp out CT hot spots. Generally, the high toe region of a golf club experiences large, non-conforming CT values. A shift in the face plate 105 CG towards the high toe signifies added mass in the high toe region to reduce CT values to a conforming range. Other hot spots may exist on the face, which can be corrected with other VFT geometries, however, the face plate 105 CG to face center relationship addresses known regions of high CT. In other instances, the faceplate CG may be shifted in a direction other than the high toe, if high CT is found to be prevalent in that direction. In some embodiments, the face plate 105 CG to face center may be offset in the X-direction between −5 mm and 3 mm (−0.197 in and 0.118 inch). In other embodiments, the face plate 105 CG to face center may be offset in the X-direction between −5 mm and −4 mm (−0.197 inch and −0.157 inch), −4 mm and −3 mm (−0.157 inch and −0.118 inch), −3 mm and −2 mm (−0.118 inch and −0.079 inch), −2 mm and −1 mm (−0.079 inch and −0.039 inch), −1 mm and 0 mm (−0.039 inch and 0 inch), 0 mm and 1 mm (0 inch and 0.039 inch), 1 mm and 2 mm (0.039 inch and 0.079 inch), or 2 mm and 3 mm (0.079 inch and 0.118 inch).

As stated above, the face plate 105 CG to face center may also be offset in the Y-direction. In some embodiments, the face plate 105 CG to face center may be offset in the Y-direction between 3 mm and −3 mm (0.118 inch and −0.118 inch). In other embodiments, the face plate 105 CG to face center may be offset in the Y-direction between 3 mm and 2 mm (0.118 inch and 0.079 inch), 2 mm and 1 mm (0.079 inch and 0.039 inch), 1 mm and 0 mm (0.039 inch and 0 inch), 0 mm and −1 mm (0 inch and −0.039 inch), −1 mm and −2 mm (−0.039 inch and −0.079 inch), or −2 mm and −3 mm (−0.079 inch and −0.118 inch).

Further, the face plate 105 CG to face center may also be offset in the Z-direction. In some embodiments, the face plate 105 CG to face center may be offset in the Z-direction between 0 mm and 5 mm (0 inch and 0.197 inch). In other embodiments, the face plate 105 CG to face center may be offset in the Y-direction between 0 mm and 1 mm (0 inch and 0.039 inch), 1 mm and 2 mm (0.039 inch and 0.079 inch), 2 mm and 3 mm (0.079 inch and 0.118 inch), 3 mm and 4 mm (0.118 inch and 0.157 inch), or 4 mm and 5 mm (0.157 inch and 0.197 inch).

XIV. Face plate CG to Central Region Geometric Center

The face plate 105 CG may be in a different location than the central region geometric center 128. Similar to what is stated above, there are typically known hot spots in the high toe region of a golf club. The central region 124 location, which may be simply viewed as the central region geometric center 128, provides the most damping when compared to the rest of the face plate VFT, due to it being thick. Thus a similar shift towards the high toe region is made in most embodiments to account for the CT hot spots in this region. Generally, while the face plate 105 CG and central region geometric center 128 may not directly line up, the face plate 105 CG will reflect the placement of the central region geometric center 128. The face plate 105 CG may be offset from the central region geometric center 128 in an X, Y, and/or Z direction. In some embodiments, the face plate 105 CG to central region geometric center 128 may be offset in the X-direction between −5 mm and 3 mm (−0.197 in and 0.118 inch). In other embodiments, the face plate 105 CG to central region geometric center 128 may be offset in the X-direction between −5 mm and −4 mm (−0.197 inch and −0.157 inch), −4 mm and −3 mm (−0.157 inch and −0.118 inch), −3 mm and −2 mm (−0.118 inch and −0.079 inch), −2 mm and −1 mm (−0.079 inch and −0.039 inch), −1 mm and 0 mm (−0.039 inch and 0 inch), 0 mm and 1 mm (0 inch and 0.039 inch), 1 mm and 2 mm (0.039 inch and 0.079 inch), or 2 mm and 3 mm (0.079 inch and 0.118 inch).

As mentioned above, the face plate 105 CG to central region geometric center 128 may also be offset in the Y-direction. In some embodiments, the face plate 105 CG to central region geometric center 128 may be offset in the Y-direction between −4 mm and 4 mm (−0.197 inch and 0.197 inch). In other embodiments, the face plate 105 CG to central region geometric center 128 may be offset in the Y-direction between −4 mm and −3 mm (−0.157 inch and −0.118 inch), −3 mm and −2 mm (−0.118 inch and −0.079 inch), −2 mm and −1 mm (−0.079 inch and −0.039 inch), −1 mm and 0 mm (−0.039 inch and 0 inch), 0 mm and 1 mm (0 inch and 0.039 inch), 1 mm and 2 mm (0.039 inch and 0.079 inch), 2 mm and 3 mm (0.079 inch and 0.118 inch), or 3 mm and 4 mm (0.118 inch and 0.157 inch)

Further, the face plate 105 CG to central region geometric center 128 may also be offset in the Z-direction. In some embodiments, the face plate 105 CG to central region geometric center 128 may be offset in the Z-direction between −3 mm and 6 mm (−0.118 inch and 0.236 inch). In other embodiments, the face plate 105 CG to central region geometric center 128 may be offset in the Z-direction between −3 mm and −2 mm (−0.118 inch and −0.079 inch), −2 mm and −1 mm (−0.079 inch and −0.039 inch), −1 mm and 0 mm (−0.039 inch and 0 inch), 0 mm and 1 mm (0 inch and 0.039 inch), 1 mm and 2 mm (0.039 inch and 0.079 inch), 2 mm and 3 mm (0.079 inch and 0.118 inch), 3 mm and 4 mm (0.118 inch and 0.157 inch), 4 mm and 5 mm (0.157 inch and 0.197 inch), or 5 mm and 6 mm (0.197 inch and 0.236 inch).

A. VFT Fully surrounded by Intermediate Region

In an exemplary embodiment, a golf club head 200, can be a fairway-type golf club head. The golf club head 200 can comprise a variable face thickness comprising a central region 224, a central perimeter 226, a first transition region 230, and a first transition region perimeter 232. The first transition region 230 can extend into the high heel (i.e., towards the heel 204 and crown 206 of the strike face) and can further have any variable radial transition distances, with reference to FIG. 8. The first transition region 230 is surrounded by an intermediate region 236 comprising a constant thickness and extending to a strike face inner perimeter 223b. In this embodiment, the intermediate region 236 entirely surrounds the first transition region 230.

XV. Rounds

In some embodiments, rounds provide smooth transitions between any combination of the previously mentioned regions to facilitate the manufacture of the VFT. The use of rounds allows the strike face 120 to vary the thickness without seams or abrupt changes in thickness between the various regions disclosed herein.

XVI. Additional Features

FIGS. 32-39 schematically illustrate various embodiments of a golf club head 100 in various views. For ease of discussion, the features shown on the golf club head 100 are applicable to various embodiments of the golf club head 100 according to the present invention. Any one or more of the features described in the various embodiments below can be used in combination with one another.

The golf club head 100 comprises a body 101 that defines an interior cavity 114 that is substantially closed/hollow. The body 101 defines a front 116, a rear 118 opposite the front 116, a heel 104, and a toe 102 opposite the heel 104. The body 101 comprises a strike face 120 near the front 116, a crown 106 near an upper portion of the golf club head 100, and a sole 108 near a lower portion of the golf club head 100. The body 101 further comprises a hosel 111 near the heel 104 for receiving a shaft or an adjustable hosel feature 178.

XVII. Multi-Material Construction

In some embodiments, the golf club head 100 is formed of multiple different materials, referred to herein as a “multi-material construction”. More specifically, one or more low-density materials, such as composite, replace metal materials in selected areas of the golf club head 100 to increase discretionary mass, which can be redeployed to increase MOI and/or locate CG as desired. The golf club head 100 body 101 comprises a frame 150 and one or more lightweight inserts. The frame 150 is formed from a metallic material to provide a durable structure that receives the one or more inserts. The frame 150 surrounds or forms one or more openings configured to receive one or more inserts. The frame 150 can surround or form a crown opening 161, a sole opening 163, a central opening 165, or various combinations thereof. The inserts can be crown inserts 152, sole inserts 153, central inserts 154 that continuously wrap around the crown 106, the sole 108, the heel 104, the toe 102, or various combinations thereof. The one or more inserts are secured to the frame 150 to define the body 101.

The frame 150 can comprise one or more materials such as steel, stainless steel, tungsten, aluminum, titanium, vanadium, chromium, cobalt, nickel, other metals, or metal alloys. In some embodiments, the frame 150 material can comprise a Ti-8Al-1Mo-1V alloy, or a 17-4 stainless steel. In some embodiments, the frame 150 material can be formed from C300, C350, Ni (Nickel)—Co(Cobalt)—Cr(Chromium)-Steel Alloy, 565 Steel, AISI type 304 or AISI type 630 stainless steel, 17-4 stainless steel, a titanium alloy, for example, but not limited to Ti-6-4, Ti-3-8-6-4-4, Ti-10-2-3, Ti 15-3-3-3, Ti 15-5-3, Ti185, Ti 6-6-2, Ti-7s, Ti-9s, Ti-92, or Ti-8-1-1 titanium alloy, an amorphous metal alloy, or other similar metals.

The one or more inserts are formed from a lightweight composite material, which increases discretionary mass by replacing portions of the body 101 that would otherwise be formed by the frame 150 material. In some embodiments, the one or more inserts can comprise a composite formed from a polymer resin and reinforcing fiber. The polymer resin can comprise a thermoset or a thermoplastic resin. In some embodiments, the one or more composite inserts can comprise a carbon fiber composite material having multiple layers of unidirectional carbon fibers formed as a single, continuous piece. In some embodiments, the one or more composite inserts may comprise a bi-directional woven carbon fiber composite material having a single layer formed as a single, continuous piece. In some embodiments, the one or more composite inserts can comprise a fiber reinforced thermo-plastic material. The one or more composite inserts can be extruded, compression molded, injection molded, blow molded or bladder molded, 3-D printed, or otherwise formed by any other appropriate forming means.

A golf club head 100 having a body 101 that comprises one or more discrete composite inserts is illustrated in FIGS. 32 and 33. Embodiments comprising one or more discrete composite inserts can include a crown insert 152, a sole insert 153, or a combination thereof. The golf club head 100 can comprise any number of crown inserts 152 and any number of sole inserts 153. Referring to FIG. 4, the crown insert 152 wraps around the heel 104 and the toe 102 and forms a portion of the sole 108. The one or more composite inserts are secured to the frame 150 to define the body 101. Each of the one or more discrete inserts is received within a corresponding opening located on the frame 150. Each opening is distinct and defined by one or more portions of the frame 150. As discussed above, the frame 150 is formed from a metallic material to provide a sturdy structure for receiving the inserts, and the inserts are formed from a lightweight composite material to create discretionary mass.

A golf club head 100 having a body 101 that comprises a continuous, central insert 154 (referred to as a “central insert 124”) is illustrated in FIGS. 34 and 35. The central insert 154 is secured to the frame 150 to define the body 101. The central insert 154 wraps continuously around the body 101 and forms at least a portion of the crown 106, at least a portion of the sole 108, and at least a portion of the body 101 perimeter near both the heel 104 and the toe 102. The central insert 154 can be a single component or multiple components. The central insert 154 is received within a central opening 165 located between a forward frame 150A and rearward frame 150B. As discussed above, the frame 150 is formed from a metallic material to provide a sturdy structure for receiving the inserts, and the central insert 154 is formed from a lightweight composite material, to create discretionary mass.

In some embodiments, the golf club head 100 can comprise an adjustable shaft-receiving mechanism to adjust the loft angle 20 and/or lie angle for a particular player, as best shown in FIG. 65A. The adjustable shaft-receiving mechanism can be similar to those described in U.S. patent application Ser. No. 15/003,494, filed on Jan. 21, 2016, now U.S. Pat. No. 9,868,035, granted on Jan. 16, 2018; and U.S. patent application Ser. No. 17/304,836, filed on Jan. 25, 2021, now U.S. Pat. No. 11,607,590, granted on Mar. 21, 2023; which are both incorporated fully herein by reference.

In the illustrated embodiment, the adjustable shaft-receiving mechanism comprises a shaft sleeve 1126 configured to receive a golf club shaft and retained within the hosel 111 by a fastener 1127. The shaft sleeve 1126 and the hosel 111 comprise complementary geometries that allow the shaft sleeve 1126 to be removably rotated into a plurality of different configurations. Rotating the shaft sleeve 1126 between different configurations will adjust a loft angle 20 and/or a lie angle 25 of the golf club head 100.

In some embodiments, as best shown in FIGS. 36-38 the golf club head 100 can comprise a lightweight shaft-receiving structure 1125 which creates discretionary mass. Referring to FIG. 36-38, the shaft-receiving structure 1125 has a reduced amount of structural mass. At least a portion of the shaft sleeve 1126 is exposed to the interior cavity 114. In the present embodiment, rather than being retained by an internal structure such as an interior hosel tube or hosel wall, the shaft sleeve 1126 is retained and supported in the golf club head 100 by structures that also form at least a portion of the exterior of the body 101. In many embodiments, the lightweight shaft-receiving structure 1125 comprises an upper end 1128A and a lower end 1128B. In the present embodiment, the shaft sleeve 1126 is secured only at the upper end 1128A and the lower end 1128B. A gap 1130 is formed between the upper end 1128A and lower end 1128B such that the gap 1130 opens into the interior cavity 114. The shaft sleeve 1126 is inserted through a hosel bore opening 1129 and retained at the upper end 1128A by the hosel 111. The shaft sleeve 1126 can be secured to the golf club head 100 by a fastener 1127.

The magnitude of discretionary mass created by the lightweight shaft-receiving structure 1125 can be quantified with reference to a hosel mass zone (HMZ) formed about a hosel axis 30, as shown in FIG. 66. The hosel axis 30 extends longitudinally through the hosel 111. In particular, the hosel mass zone (HMZ) can be formed as an imaginary cylinder centered about the hosel axis 30 and extending from the hosel bore opening 1129 toward the ground plane 10. The hosel mass zone (HMZ) may have a hosel mass zone radius RHMZ. The radius RHMZ can have a value of 2 times the outer radius (RH) of the hosel 111.

The hosel mass zone (HMZ) may contain a small amount of the total golf club head mass. For example, the golf club head mass within the hosel mass zone (HMZ) can be between 5 grams and 35 grams. In some embodiments, the golf club head mass within the hosel mass zone (HMZ) can be less than 35 grams, 30 grams, 25 grams, 20 grams, 15 grams, or less than 10 grams. A hosel mass zone (HMZ) containing a small amount of the golf club head mass is indicative of a lightweight shaft-receiving structure 1125, which effectively removes mass from the heel 104 of the golf club head 100.

The golf club head mass within the hosel mass zone (HMZ) can be described relative to the total golf club head mass. In many embodiments, the golf club head mass within the hosel mass zone (HMZ) can be between 1% and 15% of the total golf club head mass. In some embodiments, the golf club head mass within the hosel mass zone (HMZ) can be less than 15%, 14%, 13%, 12%, 11%, 10%, 9%, 8%, 7%, 6%, 5%, 4%, 3%, 2%, or less than 1% of the total golf club head mass. A hosel mass zone (HMZ) containing a small percentage of the golf club head mass is indicative of a lightweight shaft-receiving structure 1125, which effectively removes mass from the heel 104 of the golf club head 100.

The lightweight shaft-receiving structure 1125 can create between 3 grams and 12 grams of discretionary mass in comparison to a conventional shaft-receiving structure wherein, the shaft sleeve is concealed from the interior cavity 114 by a supporting structure such as a hosel tube or an interior hosel wall. In some embodiments, the lightweight shaft-receiving structure 1125 can create between 3 grams and 5 grams, 4 grams and 6 grams, 5 grams and 7 grams, 6 grams and 8 grams, 7 grams and 9 grams, 8 grams and 10 grams, 9 grams and 11 grams, or between 10 grams and 12 grams of discretionary mass in comparison to a prior-art shaft receiving structure. In some embodiments, the lightweight shaft-receiving structure 1125 can create greater than 3 grams, 4 grams, 5 grams, 6 grams, 7 grams, 8 grams, 9 grams, or greater than 10 grams of discretionary mass in comparison to a conventional shaft receiving structure. Reducing the mass of the lightweight shaft-receiving structure 1125 by eliminating redundant supporting structures increases discretionary mass to be re-allocated to other areas of the golf club head 100.

In some embodiments, the golf club head 100 can include one or more weight system(s) 170 comprising one or more removable weight(s) 172. In many embodiments, the weight system can be located in the sole 108 and/or in the rear 118. In some embodiments, the one or more weight system(s) 170 and/or the one or more removable weight(s) 172 can be located towards the sole 108 and the rear 118, thereby locating CG lower and further back on the golf club head 100. In many embodiments, the one or more weight system(s) 170 removably receive the one or more removable weight(s) 172. In these embodiments, the one or more removable weight(s) 172 can be coupled to the one or more weight system(s) 170 using any suitable method, such as a threaded fastener, an adhesive, a magnet, a snap fit, or any other mechanism capable of securing the one or more removable weight(s) 172 to the one or more weight system(s) 170. The one or more removable weight(s) 172 can adjust the moment of inertia (MOI) properties and center of gravity (CG) location.

The frame 150 can further comprise one or more mass pad(s) 174, as illustrated in FIG. 39. The one or more mass pad(s) 174 distribute weight around the golf club head 100 to achieve desired performance characteristics, such as increasing MOI or locating CG in a desirable position. The one or more mass pad(s) 174 comprise fixed concentrations of material in locations that can alter MOI, CG, or other parameters associated with the golf club head 100. The frame 150 can comprise one or more mass pad(s) 174 located along a desired portion of the frame 150. In many embodiments, discretionary mass can be distributed to the one or more mass pad(s) 174. In some embodiments, the one or more mass pad(s) 174 can be formed integrally with the frame 150. In other embodiments, the one or more mass pad(s) 174 can be formed separately and attached to the frame 150 via a coupling mechanism such as welding, brazing, mechanical coupling, adhesive coupling, or any other suitable means. In many embodiments, the one or more mass pad(s) 174 can contact a portion of the one or more composite inserts.

The golf club head 100 can include external features that produce aerodynamic effects, such as one or more turbulator(s) 176 as described in U.S. patent application Ser. No. 13/536,753, filed on Jun. 28, 2021, now U.S. Pat. No. 8,608,587, granted on Dec. 17, 2013, entitled “Golf Club Heads with Turbulators and Methods to Manufacture Golf Club Heads with Turbulators,” which is fully incorporated herein by reference. Turbulators alter the aerodynamic crown profile by disrupting and delaying flow separation, thereby reducing drag produced by the golf club head 100 during a swing.

The plurality of turbulators 176 can project from an outer surface of the crown 106 and include a length, extending between the front 116 and the rear 118 of the golf club head 100, and a width, extending from the heel 104 to the toe 102 of the golf club head 100 as illustrated in FIG. 31. In many embodiments, the length of each turbulator (in a front-to-rear direction) is greater than its width (in a heel-to-toe direction). In some embodiments, each the plurality of turbulators 176 comprises the same width. In some embodiments, one or more of the plurality of turbulators 176 can vary in height relative to the native contour of the golf club head 100 outer surface. In some embodiments, one or more of the plurality of turbulators 176 can have a greater height toward the apex of the crown 106 than near the front of the crown 106. In other embodiments, the plurality of turbulators 176 can have a greater height toward the front of the crown 106 and lower in height toward the apex of the crown 106. In other embodiments, the plurality of turbulators 176 can comprise a constant height profile. Further, in some embodiments, at least a portion of at least one turbulator 176 is located between the strike face 120 and an apex of the crown 106, and the spacing between adjacent turbulators 176 is greater than the width of each of the adjacent turbulators 176.

The wood type golf club heads disclosed herein can be a driver type golf club head, a fairway type golf club head, or a hybrid type golf club head. The various variable face thickness profiles and the features described herein can be used with an iron-type golf club head, including a hollow body iron-type golf club head and a cavity back iron-type golf club head.

XVIII. EXAMPLES

A. Exemplary Club Heads

Three driver-type golf club heads comprising varying VFT designs were manufactured and used for testing. All three golf club heads comprised an open hosel design. The three golf club heads are further referred to as Control Club Head, Exemplary Club Head 1, and Exemplary Club Head 2 and are further described below. Table 1 provides specific measurements and dimensions that describe the structure of each golf club head.

The Control Golf Club is similar to club head 4000 illustrated in FIG. 24, wherein it comprises a thickened central region near the club head face center. The first transition region extends outward from the central region in a symmetric manner into either the intermediate region or the second transition region. The intermediate region then extends into the second transition region. The first transition region abuts the second transition region (leaving no intermediate region) in the crown-ward and sole-ward portion of the VFT. Lastly, the second transition region extends into the outer region, which surrounds the entire VFT. The symmetry in the first transition region, coupled with the open hosel design is susceptible to CT values in the high heel region, due to the lack of support provided by the hosel and thin intermediate region in this area.

Exemplary Golf Club 1 is similar to FIG. 7, wherein it comprises a thickened central region near the club head face center. The first transition region extends outward from the central region in an asymmetrical manner by comprising a further extension into the high heel portion. The first transition region still extends into either the intermediate region or second transition region, however, the area of the intermediate region in the heel portion is reduced compared to the Control Golf Club. The area of the first transition region is thereby also increased. The first transition region abuts the second transition region (leaving no intermediate region) in the sole-ward, crown-ward, and heel-side crown-ward portion of the VFT. Similar to the Control Golf Club, the second transition region extends into the outer region, which entirely surrounds the VFT. The extension of the first transition region into the high heel acts as a method of reducing CT in a region of high CT response due to the lack of support provided by the open hosel design.

Exemplary Golf Club 2 is similar to FIG. 22, wherein it comprises a thickened central region near the club head face center. The first transition region extends outward from the central region in an asymmetrical manner by comprising a further extension into the high heel portion. Additionally, the first transition region is shortened in the sole-ward direction, such that the first transition region does not abut the second transition region in the sole-ward portion of the VFT (unlike the Control Golf Club and Exemplary Golf Club 1). Therefore, the first transition region extends into intermediate region in the crown-ward, toe-ward, sole-ward, and low heel-ward portion of the VFT. The first transition region abuts the second transition region in the high heel portion of the VFT. Similar to the Control Golf Club and Exemplary Golf Club 1, the second transition region extends into the outer region, which entirely surrounds the VFT. The extension of the first transition region into the high heel acts as a method of reducing CT in a region of high CT response due to the lack of support provided by the open hosel design. Further, shortening the first transition region in the sole-ward direction increases CT in the sole portion of the VFT, which is traditionally known as an area of low CT response.

Additionally, the VFT designs of the three test clubs may further be described based on how the central region geometric center and the first transition region geometric center is shifted relative to the geometric face center. This provides insight to how the first transition region may be shaped, such as extending or shortening in different portions of the face. The different shapes are used to correct for high or low CT regions. In these measurements, the origin is the geometric face center, wherein the positive X-direction is towards the heel of the golf club head and the positive Y-direction is towards the crown of the golf club head. In the Control Golf Club, the central region geometric center is offset from the face geometric center by 0.150 inch toe-ward, with no shift in the Y-direction. The first transition region geometric center is offset 0.150 inch toe-ward and 0.021 inch towards the crown. Exemplary Club Head 1 had a central region geometric center offset from the face geometric center by 0.075 inch toe-ward, with a no shift in the Y direction. The first transition region geometric center is offset 0.008 inch heel-ward and 0.039 inch towards the crown. Exemplary Club Head 2 had a central region geometric center offset from the face geometric center by 0.075 inch toe-ward and no shift in the Y direction. The first transition region geometric center is offset 0.065 inch heel-ward and 0.111 inch towards the crown. These measurements may be seen in Table 2 below. It should be noticed that the first transition region geometric center is progressively shifted in the high heel direction in the test clubs. Specifically, Exemplary Club Head 2 comprises the highest and most heel-ward shift in the first transition region geometric center. This can be attributed to the extension of the first transition region into the high heel region and the sole-ward first transition region being shortened. This is used to address the high heel hot spots (due to the open hosel design) and the low CT values nearer the sole.

As mentioned above, Tables 1 and 2 below provide specific measurements and dimensions related to the quantifying and describing the structure of each golf club head. These three golf club heads are used in the remaining examples, as well, and will be recalled.

TABLE 1
		Control	Exemplary	Exemplary
Angle (Θ)		Club	Club Head	Club Head
[degrees]	Measurement	Head	1	2
Θ1 (0°)	First transition length	0.527	0.521	0.524
	[inch]
	Theoretical First	0.590	0.583	0.530
	transition length [inch]
	Thickness @ Transition	0.082	0.085	0.082
	Region Perimeter [inch]
	Angle [degrees]	2.1	2.1	2.3
	Rise [inch]	0.019	0.019	0.021
	Run [inch]	0.527	0.520	0.524
	Loft Plane Slope	0.0360	0.0370	0.0401
	First transition thickness	0.044	0.043	0.044
	change [inch]
	Thickness Slope	0.083	0.083	0.083
Θ2 (30°)	First transition length	0.621	0.616	0.606
	[inch]
	Theoretical First	0.640	N/A	N/A
	transition length [inch]
	Thickness @ Transition	0.078	0.078	0.076
	Region Perimeter [inch]
	Angle [degrees]	1.6	1.6	1.8
	Rise [inch]	0.017	0.017	0.019
	Run [inch]	0.621	0.616	0.606
	Loft Plane Slope	0.0270	0.0280	0.0314
	First transition thickness	0.048	0.050	0.050
	change[inch]
	Thickness Slope	0.077	0.081	0.083
Θ3 (60°)	First transition length	0.746	0.730	0.709
	[inch]
	Theoretical First	N/A	N/A	N/A
	transition length [inch]
	Thickness @ Transition	0.076	0.078	0.076
	Region Perimeter [inch]
	Angle [degrees]	0.1	0.7	0.1
	Rise [inch]	0.004	0.006	0.008
	Run [inch]	0.746	0.730	0.710
	Loft Plane Slope	0.0050	0.0080	0.0113
	First transition thickness	0.050	0.050	0.050
	change[inch]
	Thickness Slope	0.067	0.680	0.070
Θ4 (90°)	First transition length
	[inch]
	Theoretical First	N/A	N/A	N/A
	transition length [inch]
	Thickness @ Transition	0.076	0.078	0.076
	Region Perimeter [inch]
	Angle [degrees]	0.1	0.1	0.1
	Rise [inch]	0.001	0.001	0.001
	Run [inch]	0.728	0.759	0.760
	Loft Plane Slope	0.0010	0.0010	0.0013
	First transition thickness	0.050	0.050	0.050
	change[inch]
	Thickness Slope	0.069	0.066	0.066
Θ5 (120°)	First transition length	0.683	0.689	0.539
	[inch]
	Theoretical First	N/A	N/A	N/A
	transition length [inch]
	Thickness @ Transition	0.076	0.078	0.076
	Region Perimeter [inch]
	Angle [degrees]	0.1	0.7	2.1
	Rise [inch]	0.005	0.006	0.020
	Run [inch]	0.683	0.689	0.539
	Loft Plane Slope	0.0070	0.0090	0.0371
	First transition thickness	0.050	0.050	0.050
	change[inch]
	Thickness Slope	0.073	0.073	0.093
Θ6 (150°)	First transition length	0.555	0.560	0.359
	[inch]
	Theoretical First	0.593	0.585	N/A
	transition length [inch]
	Thickness @ Transition	0.081	0.081	0.076
	Region Perimeter [inch]
	Angle [degrees]	1.3	1.4	5.3
	Rise [inch]	0.013	0.014	0.033
	Run [inch]	0.555	0.560	0.357
	Loft Plane Slope	0.0230	0.0250	0.0924
	First transition thickness	0.045	0.047	0.050
	change[inch]
	Thickness Slope	0.081	0.084	0.140
Θ7 (180°)	First transition length	0.520	0.512	0.327
	[inch]
	Theoretical First	0.546	0.542	N/A
	transition length [inch]
	Thickness @ Transition	0.080	0.081	0.076
	Region Perimeter [inch]
	Angle [degrees]	1.8	1.8	6.0
	Rise [inch]	0.016	0.016	0.035
	Run [inch]	0.520	0.511	0.324
	Loft Plane Slope	0.0310	0.0310	0.1080
	First transition thickness	0.046	0.047	0.050
	change[inch]
	Thickness Slope	0.089	0.092	0.154
Θ8 (210°)	First transition length	0.575	0.571	0.394
	[inch]
	Theoretical First	N/A	N/A	N/A
	transition length [inch]
	Thickness @ Transition	0.076	0.078	0.076
	Region Perimeter [inch]
	Angle [degrees]	1.6	1.5	4.5
	Rise [inch]	0.016	0.014	0.031
	Run [inch]	0.575	0.570	0.392
	Loft Plane Slope	0.0280	0.0250	0.0791
	First transition thickness	0.050	0.050	0.050
	change[inch]
	Thickness Slope	0.087	0.088	0.128
Θ9 (240°)	First transition length	0.679	0.719	0.636
	[inch]
	Theoretical First	N/A	N/A	N/A
	transition length [inch]
	Thickness @ Transition	0.076	0.078	0.076
	Region Perimeter [inch]
	Angle [degrees]	0.1	0.7	1.0
	Rise [inch]	0.010	0.004	0.012
	Run [inch]	0.679	0.719	0.635
	Loft Plane Slope	0.0150	0.0060	0.0189
	First transition thickness	0.050	0.050	0.050
	change[inch]
	Thickness Slope	0.074	0.070	0.079
Θ10 (270°)	First transition length	0.760	0.910	0.985
	[inch]
	Theoretical First	N/A	N/A	N/A
	transition length [inch]
	Thickness @ Transition	0.076	0.078	0.076
	Region Perimeter [inch]
	Angle [degrees]	0.1	1.1	1.5
	Rise [inch]	0.001	0.017	0.026
	Run [inch]	0.760	0.910	0.985
	Loft Plane Slope	0.0010	0.0190	0.2640
	First transition thickness	0.050	0.050	0.050
	change[inch]
	Thickness Slope	0.660	0.055	0.051
Θ11 (285°)	First transition length	0.748	0.948	0.982
	[inch]
	Theoretical First	N/A	N/A	1.078
	transition length [inch]
	Thickness @ Transition	0.076	0.078	0.086
	Region Perimeter [inch]
	Angle [degrees]	0.1	1.2	0.8
	Rise [inch]	0.001	0.020	0.033
	Run [inch]	0.748	0.948	0.982
	Loft Plane Slope	0.0010	0.0210	0.0336
	First transition thickness	0.050	0.050	0.040
	change[inch]
	Thickness Slope	0.067	0.053	0.040
Θ12 (300°)	First transition length	0.704	0.793	0.798
	[inch]
	Theoretical First	N/A	0.902	0.943
	transition length [inch]
	Thickness @ Transition	0.076	0.087	0.090
	Region Perimeter [inch]
	Angle [degrees]	0.8	0.2	0.1
	Rise [inch]	0.008	0.010	0.013
	Run [inch]	0.704	0.793	0.798
	Loft Plane Slope	0.0110	0.0130	0.0163
	First transition thickness	0.050	0.041	0.036
	change[inch]
	Thickness Slope	0.071	0.051	0.045
Θ13 (330°)	First transition length	0.565	0.560	0.559
	[inch]
	Theoretical First	0.616	0.666	0.639
	transition length [inch]
	Thickness @ Transition	0.081	0.088	0.860
	Region Perimeter [inch]
	Angle [degrees]	1.8	1.3	1.5
	Rise [inch]	0.018	0.012	0.014
	Run [inch]	0.564	0.560	0.559
	Loft Plane Slope	0.0320	0.0210	0.0250
	First transition thickness	0.045	0.040	0.040
	change[inch]
	Thickness Slope	0.080	0.071	0.072

TABLE 2
Shifts from Geometric Face Center
	Central Region	First Transition Region
	Shift [in]	Geometric Center Shift [in]
	X	Y	X	Y
Control Club Head	−0.150	0	−0.150	0.021
Exemplary Club	−0.075	0	0.008	0.039
Head 1
Exemplary Club	−0.075	0	0.065	0.111
Head 2

B. CT Map 1

As mentioned in the earlier disclosure, CT can vary across the face of a golf club. A specifically designed VFT can act to better normalize CT over the entirety of the face, which results in less ball speed loss on mishits. Retaining ball speed on mishits allows players to maintain distance on off-center strikes, thus the club is more forgiving. Normalized CT across the face is a strong factor for consistent ball speed, and the exemplary VFT design better achieves this.

A CT test was conducted utilizing the USGA pendulum apparatus on Exemplary Golf Club 2 (described in Example A above). In this test, one strike at the USGA upper height was performed at 15 discrete locations across 10 separate faces with the VFT described above. The normalized CT at each point was averaged over each of the 10 faces to produce the CT map shown in FIG. 23. The locations tested were at face center, 10.16 mm above and below the face center, 10.16 mm heel side and toe side of the face center, and 20.32 mm heel side and toe side of the face center. CT values were normalized by the CT at the face center location, wherein the CT values represent the CT deviation at various locations on the face. FIG. 23 shows a CT drop off on low strikes (near the sole) and increased CT in the high toe region (near the crown). While there are slight deviations in the CT at various locations, Exemplary Golf Club 2 was found to provide a normal CT across the face.

C. Durability Testing

Durability testing of the exemplary VFT was conducted using an air cannon, wherein golf balls repeatedly impacted the club face at 130 miles per hour (MPH) until failure. Failure can be in the form of cracks or the face being penetrated by the golf ball. Seven separate golf club heads were tested that comprised the same design as Exemplary Golf Club 2. On average, Exemplary Golf Club 2 withstood approximately 2,094 impacts before failure. Some samples withstood up to approximately 3,250 impacts before failure. Generally, a golf club head is deemed to have passed the durability test if it can sustain at least 2,000 impacts before failure. Given the average of 2,094 impacts sustained by Exemplary Golf Club 2 before failure, the exemplary golf club head passed the durability test.

D. VFT CT Comparisons

In another experiment, CT measurements were measured on three golf club heads comprising different VFT designs. The three designs were the golf club heads described in Example A (Control Golf Club, Exemplary Golf Club 1, and Exemplary Golf Club 2). The Control Golf Club comprised a first transition region, symmetric around the central region, and which extended into the second transition region in the crown-ward and sole-ward portion of the VFT. Additionally, an intermediate region was found in the toe-ward and heel-ward portion of the VFT. Exemplary Golf Club 1 comprised a first transition region similar to the Control Golf Club, however it was asymmetric around the central region, due to the first transition region being extended into the high heel. Exemplary Golf Club 2 comprised a first transition region similar to Exemplary Golf Club 1, however, it comprised a shortened first transition region in the sole-ward portion of the VFT. More description and specific measurements and dimensions of the test golf clubs are described above in Example A.

CT was measured on the club heads by performing a single, high pendulum drop test (according to USGA measurement standards) at 231 discrete locations. Measurements were collected at every point in a rectangular grid, separated by 2 mm, starting at face center, extending crown-ward 12 mm from face center, 8 mm sole-ward from face center, 20 mm heel-ward from face center, and 20 mm toe-ward of face center. This rectangular grid is further referred to as the test area.

CT measurements taken on the Control Club Head comprising a VFT having a first transition region extending outward from a central region, wherein the first transition region symmetrically surrounded the central region, shown in FIG. 24. The results of this test may be seen in FIG. 25, which shows a particularly high CT region in the high heel portion of the face. This is highlighted in the difference between the maximum and minimum CT values, which were 261 us and 227 μs, respectively, equating to a difference of 34 μs. Shrinking the difference between these values represents a more normalized CT across the face.

In an exemplary club head comprising the VFT as described in Example A (Exemplary Golf Club 1), the first transition region extends outward from the central region in a less symmetric manner. Specifically, the first transition region extended further into the high heel region (shown in FIG. 7) to reduce the CT to conforming values. Exemplary Club Head 1 succeeded in reducing the CT in the high heel region, but also noticed a reduction in the sole-ward region CT. The CT results of Exemplary Golf Club 1 can be seen in FIG. 26. Overall, the maximum and minimum CT value across the test area was 248 us and 223 μs, respectively. Therefore, the high CT values were reduced to conforming values, with a difference between the maximum and minimum CT values being lowered from 34 us in the control club to 25 us in Exemplary Club 1, and thus more normalized.

In another exemplary club head comprising the VFT as described in Example A (Exemplary Golf Club 2), the first transition region extends outward from the central region. In this exemplary embodiment, the extension into the high heel (as described in Exemplary Golf Club 1) is still present, and the sole-ward first transition region is shortened. This VFT design is depicted in FIG. 22. This provides a steeper fall off from the central region to a thinner intermediate region. The thinner thicknesses correspond to a higher CT value, thus contributing to raising the lower CT values seen in Exemplary Golf Club 1 (FIG. 26). Following the CT test across the test area, Exemplary Club Head 2 produced a CT map as shown in FIG. 27. In this test, Exemplary Club 2 produced a maximum CT of 255 us and a minimum CT of 236 μs, resulting in a difference of 19 μs. Exemplary Club 2 thereby produced the most normalized CT across the three clubs tested in the example.

Table 3 below shows statistics relating to the CT values of the control club head, Exemplary Club Head 1, and Exemplary Club Head 2. The difference in the maximum and minimum CT values show a convergence on a more normalized face, due to the differing VFT designs. The difference was decreased in both exemplary clubs when compared to the control club head. This signifies less variation of CT across the face. In addition, the number of outliers can be found by comparing the amount of large deviations from the mean. For instance, a large deviation can be described as a CT value that is over or under eight CT points from the mean of all measured values. Generally, one CT point equates to 0.2 mph of ball speed. The control club head comprised 18% of values outside the 8 us from the mean threshold, while Exemplary Club Head 1 had 9% outside, and Exemplary Club Head 2 had 1% outside. This shows that CT values across the face are more consistent across the face by reducing the number of outliers, leading to less ball speed variation on strikes that contact different face portions.

	TABLE 3
					% of
			Maximum		Points
			CT −		8 μs
	Maximum	Minimum	Minimum	Mean	from
	CT [μs]	CT [μs]	CT [μs]	CT [μs]	Mean
Control	261	227	34	248	18
Club Head
Exemplary	248	223	25	238	9
Club Head 1
Exemplary	255	236	19	250	1
Club Head 2

XIX. Clauses

• • Clause 1: A golf club head, comprising: a strike face, comprising: a central region including a geometric center of the strike face and having a central region thickness that is constant; a first transition region surrounding the central region and having a first varying thickness; and an intermediate region surrounding the first transition region and having an intermediate region thickness that is constant; a second transition region surrounding both a portion of the first transition region and a portion of the intermediate region and having a second varying thickness; an outer region surrounding the second transition region and having an outer region thickness that is constant; wherein the second varying thickness increases in thickness from the portion of the first transition region and the portion of the intermediate region to an outer region and having a second varying thickness; wherein the central region thickness comprises a maximum thickness, the intermediate region comprises a minimum thickness, the outer region comprises a thickness greater than the intermediate region thickness and less than the central region thickness, the first varying thickness is between the maximum thickness and the minimum thickness, and the second varying thickness is between the minimum thickness and the outer region thickness; the first transition region extends outwards from a central region perimeter, wherein the distance the first transition region extends varies depending on an angle formed between the z-axis and an imaginary line formed extending from the face center to a first transition region perimeter wherein; from 260 degrees to 310 degrees a theoretical first transition length is greater than 21 mm.
  • Clause 2: The golf club head of clause 1, wherein from 260 degrees to 310 degrees, a thickness slope is less than 0.06.
  • Clause 3: The golf club head of clause 1, wherein from 260 degrees to 310 degrees, a first transition run is greater than 20 mm.
  • Clause 4: The golf club head of clause 1, wherein from 260 degrees to 310 degrees, a first transition length is greater than 20 mm.
  • Clause 5: The golf club head of clause 1, wherein the second transition region surrounds between 25% and 100% of the first transition region.
  • Clause 6: The golf club head of clause 1, wherein the intermediate region surrounds between 45% and 55% of the first transition region.
  • Clause 7: The golf club head of clause 1, wherein from 30 degrees to 60 degrees, a first transition length is between 15 mm and 20 mm.
  • Clause 8: The golf club head of clause 1, wherein from 30 degrees to 60 degrees, a first transition run is between 13 mm and 20 mm.
  • Clause 9: The golf club head of clause 1, wherein from 30 degrees to 60 degrees, a thickness slope is between 0.05 and 0.10.
  • Clause 10: The golf club head of clause 1, wherein from 30 degrees to 60 degrees, the theoretical first transition length is between 15 mm and 20 mm.
  • Clause 11: A golf club head, comprising: a strike face, comprising: a central region including a geometric center of the strike face and having a central region thickness that is constant; a first transition region surrounding the central region and having a first varying thickness; and an intermediate region surrounding the first transition region and having an intermediate region thickness that is constant; a second transition region surrounding both a portion of the first transition region and a portion of the intermediate region and having a second varying thickness; an outer region surrounding the second transition region and having an outer region thickness that is constant; wherein the second varying thickness increases in thickness from the portion of the first transition region and the portion of the intermediate region to an outer region and having a second varying thickness; wherein the central region thickness comprises a maximum thickness, the intermediate region comprises a minimum thickness, the outer region comprises a thickness greater than the intermediate region thickness and less than the central region thickness, the first varying thickness is between the maximum thickness and the minimum thickness, and the second varying thickness is between the minimum thickness and the outer region thickness; the first transition region extends outwards from a central region perimeter, wherein the distance the first transition region extends varies depending on an angle formed between the z-axis and an imaginary line formed extending from the face center to a first transition region perimeter wherein; from 140 degrees to 220 degrees a first transition included angle is greater than 4 degrees.
  • Clause 12: The golf club head of clause 11, wherein from 140 degrees to 220 degrees, the first transition included angle is greater than 6 degrees.
  • Clause 13: The golf club head of clause 11, wherein from 140 degrees to 220 degrees, a thickness slope is greater than 0.12.
  • Clause 14: The golf club head of clause 11, wherein from 160 degrees to 200 degrees, a thickness slope is greater than 0.15.
  • Clause 15: The golf club head of clause 11, wherein from 140 degrees to 220 degrees, a first transition run is less than 10 mm.
  • Clause 16: The golf club head of clause 11, wherein from 140 degrees to 220 degrees, a first transition length is less than 10.5 mm.
  • Clause 17: The golf club head of clause 11, wherein at 180 degrees, a first transition length is between 7 and 14 mm.
  • Clause 18: The golf club head of clause 11, wherein at 180 degrees, a first transition run is between 6 mm and 14 mm.
  • Clause 19: The golf club of clause 11, wherein the intermediate region surrounds between 25% and 100% of the first transition region.
  • Clause 20: The golf club of clause 11, wherein the second transition region surrounds between 25% and 100% of the first transition region.

Claims

1. A golf club head, comprising: a strike face, comprising: a central region including a geometric center of the strike face and having a central region thickness that is constant;a first transition region surrounding the central region and having a first varying thickness; andan intermediate region surrounding the first transition region and having an intermediate region thickness that is constant;a second transition region surrounding both a portion of the first transition region and a portion of the intermediate region and having a second varying thickness;an outer region surrounding the second transition region and having an outer region thickness that is constant; wherein the second varying thickness increases in thickness from the portion of the first transition region and the portion of the intermediate region to an outer region and having a second varying thickness;wherein the central region thickness comprises a maximum thickness, the intermediate region comprises a minimum thickness, the outer region comprises a thickness greater than the intermediate region thickness and less than the central region thickness, the first varying thickness is between the maximum thickness and the minimum thickness, and the second varying thickness is between the minimum thickness and the outer region thickness;the first transition region extends outwards from a central region perimeter, wherein the distance the first transition region extends varies depending on an angle formed between the z-axis and an imaginary line formed extending from the face center to a first transition region perimeter wherein; from 260 degrees to 310 degrees a theoretical first transition length is greater than 21 mm.

2. The golf club head of claim 1, wherein from 260 degrees to 310 degrees, a thickness slope is less than 0.06.

3. The golf club head of claim 1, wherein from 260 degrees to 310 degrees, a first transition run is greater than 20 mm.

4. The golf club head of claim 1, wherein from 260 degrees to 310 degrees, a first transition length is greater than 20 mm.

5. The golf club head of claim 1, wherein the second transition region surrounds between 25% and 100% of the first transition region.

6. The golf club head of claim 1, wherein the intermediate region surrounds between 45% and 55% of the first transition region.

7. The golf club head of claim 1, wherein from 30 degrees to 60 degrees, a first transition length is between 15 mm and 20 mm.

8. The golf club head of claim 1, wherein from 30 degrees to 60 degrees, a first transition run is between 13 mm and 20 mm.

9. The golf club head of claim 1, wherein from 30 degrees to 60 degrees, a thickness slope is between 0.05 and 0.10.

10. The golf club head of claim 1, wherein from 30 degrees to 60 degrees, the theoretical first transition length is between 15 mm and 20 mm.

11. A golf club head, comprising: a strike face, comprising: a central region including a geometric center of the strike face and having a central region thickness that is constant;a first transition region surrounding the central region and having a first varying thickness; andan intermediate region surrounding the first transition region and having an intermediate region thickness that is constant;a second transition region surrounding both a portion of the first transition region and a portion of the intermediate region and having a second varying thickness;an outer region surrounding the second transition region and having an outer region thickness that is constant; wherein the second varying thickness increases in thickness from the portion of the first transition region and the portion of the intermediate region to an outer region and having a second varying thickness;wherein the central region thickness comprises a maximum thickness, the intermediate region comprises a minimum thickness, the outer region comprises a thickness greater than the intermediate region thickness and less than the central region thickness, the first varying thickness is between the maximum thickness and the minimum thickness, and the second varying thickness is between the minimum thickness and the outer region thickness;the first transition region extends outwards from a central region perimeter, wherein the distance the first transition region extends varies depending on an angle formed between the z-axis and an imaginary line formed extending from the face center to a first transition region perimeter wherein; from 140 degrees to 220 degrees a first transition included angle is greater than 4 degrees.

12. The golf club head of claim 11, wherein from 140 degrees to 220 degrees, the first transition included angle is greater than 6 degrees.

13. The golf club head of claim 11, wherein from 140 degrees to 220 degrees, a thickness slope is greater than 0.12.

14. The golf club head of claim 11, wherein from 160 degrees to 200 degrees, a thickness slope is greater than 0.15.

15. The golf club head of claim 11, wherein from 140 degrees to 220 degrees, a first transition run is less than 10 mm.

16. The golf club head of claim 11, wherein from 140 degrees to 220 degrees, a first transition length is less than 10.5 mm.

17. The golf club head of claim 11, wherein at 180 degrees, a first transition length is between 7 and 14 mm.

18. The golf club head of claim 11, wherein at 180 degrees, a first transition run is between 6 mm and 14 mm.

19. The golf club of claim 11, wherein the intermediate region surrounds between 25% and 100% of the first transition region.

20. The golf club of claim 11, wherein the second transition region surrounds between 25% and 100% of the first transition region.