Patent Application
20250205565
Golf clubs from a technical perspective undergo a unique set of rigors. For example, golf clubs are evaluated in their ability to meet performance thresholds such as efficient transfer of energy to a golf ball upon impact. Golf clubs are also evaluated in terms of their ability to provide forgiveness on off-centered shots or mis-hits. Further, golf clubs in some cases are evaluated in their ability to impart specific spin characteristics or other attributes to a golf ball upon impact for shaping flight trajectory and/or ball roll characteristics. Apart from performance, club heads are expected to withstand repeated use, e.g. resist wear, rust, and material fatiguing. Some club heads are also expected to permit a degree of adjustability by plastic deformation, e.g. hosel bending to adjust loft and/or lie.
Golf club manufacturers desire to achieve success across all or as many of these aspects of use as possible. But the varied nature of these functional desirables, and provision of limitations, e.g. regarding mass, physical dimensions, and cost, often lead to design conflicts and tradeoffs. For example, increasing the forgiveness of a club head, e.g. by increasing its moment of inertia about preferred axes often comes at the cost of desirable feel. Similarly, adapting a club head to impart beneficial spin and wear resistance may likely involve a material selection that could adversely affect other considerations. For example, conventional materials that offer high hardness, high yield strength and adequate machineability often fall short in other key areas such as malleability or softness, which is preferable regarding the provision of adjustability or bendability.
To minimize the severity of such design trade-offs, manufacturers have considered selectively varying club head materials about the structure of the club head to better match material properties with structural function. For example, iron-type club heads, e.g. wedges, have implemented face inserts of a material different from that of a main body to which the face insert is secured. Accordingly, the face insert may be selected to exhibit properties ideal for impact, such as relatively high hardness, low density, adequate wear resistance, and adequate machineability. Yet, the material of the main body may appropriately depart from those properties and instead be selected to exhibit e.g. a higher density and greater malleability.
Selectively positioning different materials about the structure of a club head, although with apparent benefit, is not without detriment. First, increasing the number of components constituting a club head increases its cost and complexity in manufacture. As a result, margins of error in manufacturing may increase as may locations of failure e.g. given the imposition of adhesives, mechanical fasteners and heat-affected zones resulting from welding or brazing. Also, departure of a club head from solid structure toward componentized structure may result in deleterious loss of feel and poor acoustics or vibratory properties.
An object, therefore, of the present disclosure is to provide material compositions, and implementations thereof, that are in themselves suitable for varied use aspects expected of golf club heads. Accordingly, benefits associated with selectively corresponding material properties with particular club head structure may be achieved, while detriments associated with unduly componentized structure may be minimized or avoided.
In one aspect, a golf club head includes a unitary component formed of a stainless steel material. The unitary component has variable hardness. A first portion of the component exhibits a first hardness H1 no less than 50HRC. A second portion of the component exhibits a second hardness H2 no greater than 85HRB.
In another aspect of the present disclosure, a method includes forming a component of a golf club head. The component comprises a stainless steel material. The method includes selectively surface hardening the component such that a first portion of the component exhibits a first hardness H1 no less than 50HRC and a second portion of the component exhibits a second hardness H2 no greater than 85HRB.
In another aspect of the present disclosure, a component for a golf club head includes a stainless steel material. The stainless steel material has a Nickel content no greater than 0.25% by mass.
In another aspect of the present disclosure, a component for a golf club head includes a stainless steel material. The stainless steel material has a Carbon content no less than 0.25% by mass.
In another aspect of the present disclosure, a component for a golf club head includes a stainless steel material. The stainless steel material has an austenization temperature no less than 800° C.
These and other features and advantages of the golf club heads, their compositions, and manufacturing methods thereof according to the various aspects of the present disclosure will become more apparent upon consideration of the following description, drawings, and appended claims. The description and drawings described below are for illustrative purposes only and are not intended to limit the scope of the present invention in any manner.
In one aspect of the present disclosure, referring to
Preferably, the club head 100 is an iron-type club head, e.g. having a loft between 20° and 66°. More preferably, the club head 100 is a wedge-type club head, e.g. having a loft between 40° and 66°. Additionally, or alternatively, the club head 100 bears a lie between about 62° and about 66°, more preferably between 61° and 63°. However, the structures and material compositions described herein may readily apply to other types of golf club heads, e.g. woods including drivers, fairway woods, and hybrids, as well as putters, rescue clubs, etc.
The golf club head preferably comprises a steel material, preferably a stainless steel material. Typically, readily-available grades of stainless steel are conventionally applied to golf club head construction, particularly iron-type, including wedge-type, club heads. For example, AISI 431 alloy steel is a commonly used component of golf club heads. However, in consideration of the unique set of rigors and constraints associated with golf club heads, particularly wedge-type golf club heads, as well as the desire to minimize the severity of design trade-offs, steel compositions deviating from say AISI 431 may be advantageous. For purposes herein, a steel alloy is considered to be a stainless steel if its Chromium content is at least 10.5% by mass.
Preferably, a majority (i.e. greater than 50%) of the club head 100, by mass, is comprised of such steel, more preferably at least 85% of the club head 100, even more preferably substantially the entirety of the club head 100 (e.g. accounting for minor auxiliary components such as paints, thin coatings, mouse glue, ferrules, etc.). Alternatively or additionally, such steel preferably constitutes a unitary component of the club head 100, more preferably a unitary component that includes a first portion forming at least a portion of the striking face 102, even more preferably also including a second portion forming at least a portion of the hosel portion 104 and yet even more preferably including a third portion forming at least a portion of the rear portion 116 of the club head 100. The club head 100 is preferably solid in shape having an upper blade portion 118 and lower muscle portion 120 proximate the sole portion 108. In some embodiments, substantially the entirety of the club head 100 is unitarily formed of such steel. As discussed above, reducing the number of the components required in the build of the club head 100 may provide benefits in reducing manufacturing cost, reducing manufacturing tolerances, reducing locations susceptible to failure, while maintaining desirable feel, acoustics and vibratory characteristics.
Preferably, though, the composition of the steel described above is selected such that it provides material properties that are particularly beneficial for use in a golf club head. Conventionally available grades of steel provide for some adequate properties regarding club heads but may also be procured to exhibit properties believed not to be particular relevant for use in a club head. For at least these reasons, tailoring steel composition for use associated with club heads may provide benefits with no or little detriment. Also, preferably, tailoring steel composition for use associated with club heads may permit greater flexibility in varying club head properties by structure.
As described above, the golf club head 100 is preferably an iron-type club head, more preferably a wedge-type club head. Accordingly, adapting main body material composition to the specific use aspects of such club heads may result in outweighed benefit. Particular attention is drawn to hardness characteristics, wear resistance and density for their believed relevance to wedge-type club heads. However, other characteristics may be taken into consideration also.
Hardness is an example of a property of which desirable application is unique in the case of golf club heads. On one hand, a striking face, e.g. striking face 102, preferably comprises a relatively hard surface. Yet, other portions of a club head, e.g. club head 100, are preferably softer and more malleable, e.g. the hosel portion 104. Such malleability supports adjustability by plastically deforming the club head, e.g. modifying loft and/or lie by hosel bending. This duality in hardness desirability is a unique aspect of golf club head functionality and is believed to justify deviation from conventional material composition.
One concern regarding conventional steels is their limitations in providing for manipulation of hardness. For example, 431 Stainless Steel exhibits an austenization temperature of about 720° C., which in turn enables tempering at a temperature no greater than about 700° C.; exceeding this temperature deleteriously raises the likelihood of austenite transformation and rehardening. Thus, maintaining malleable qualities while achieving a striking face of relatively high hardness may be challenging.
Such limitations on hardening are believed closely correlated with Nickel content in steels, other material constituents notwithstanding. Nickel is believed to be a strong austenite promoter. This in turn is believed to affect, by decreasing, an austenization temperature. In turn, this is believed to raise the minimum achievable hardness by such steel in a quenched and tempered state. For example, 431 Stainless Steel is believed only capable of being softened to about 85HRB. Remedial processes may counteract this deficiency, such as a softening processes that includes holding such steels at temperatures about their austenization temperature and slowly cooling. However, these remedial processes are not without detriment themselves, e.g. reduced wear resistance. Such remedial processes also complicate, and increase the cost of, manufacturing. Thus, a steel composition capable of achieving desirable variation in hardness, by virtue of quenching and tempering, alone, is preferable.
Accordingly, the steel composition of the club head 100 preferably comprises a Nickel content no greater than 0.5% by mass, more preferably no greater than 0.35% by mass. However, notably, even reducing Nickel composition to no greater than 0.25% by mass, or more preferably about 0.2% by mass, the club head may be capability of exhibiting superior properties, e.g. hardness variation and wear resistance, with little believed detriment. Provided such a Nickel content, the steel can exhibit an austenization temperature no less than 800° C., preferably no less than 850° C., and even more preferably equal to about 870° C. Accordingly, the steel may likely be capable of being tempered at temperatures of at least 800° C. This may result in a capability to soften the steel to 90HRB or less after quenching and tempering, substantially increasing bendability, e.g. to accommodate loft and/or lie adjustment by hosel bending. Preferably, the steel exhibits material properties permitting up to about 4° of angular adjustment of the hosel portion whether in loft adjustment or lie adjustment. Generally, in some alternative embodiments, the content of Nickel may be reduced to be below 0.2% without significant detriment, particularly in the case of a wedge-type club head. However, lower limits of Nickel content may correspond to unacceptable impact energy and should be evaluated on that basis.
Hardness characteristics of steel are also believed substantially affected by Carbon content. Increasing Carbon may generally be considered to increase maximum achievable hardness of a steel in a quenched state. For example, other material constituents notwithstanding, 431 Stainless Steel is believed to have a Carbon content of about 0.1% by mass and to exhibit a maximum hardness in a quenched state of around 40HRC. 8620 Stainless Steel is believed to have a Carbon content of about 0.2% by mass and to exhibit a maximum hardness in a quenched state of about 45HRC. Preferably, the steel of the club head 100 has a Carbon content of no less than 0.13% by mass, more preferably no less than 0.25% by mass. Other constituents notwithstanding, the steel of the club head 100 in a quenched state can exhibit a hardness no less than 50HRC, more preferably no less than 55HRC, even more preferably no less than 60HRC and yet even more preferably between 60HRC and 65HRC.
In addition to its own direct benefits, Carbon is believed, to a degree, to be an effective substitute for Nickel. Thus Carbon permits the advantageous reduction in Nickel content described above. In addition to such hardness benefits, such Carbon content limitations are believed to contribute to improved wear resistance and reduced material density.
If Carbon content is too high, however, deleterious effects may result. For example, manufacturing issues such as problems with weldability and solidification may be presented. Also, Carbon content, in association with Nickel and other constituents, is believed to contribute to the steel's austenization temperature. Specifically, a relatively high Carbon content may lower austenization temperature as it is believed to be a strong austenite promoter. As a result, the steel may be deleteriously limited in its above-mentioned capability to be softened by tempering to a hardness no greater than 90HRB. Thus, the steel of the club head 100 preferably has a Carbon content between 0.13% and 0.50% by mass, more preferably between 0.25% and 0.50% by mass. However, higher Carbon contents, e.g. in a range of 0.45% to 0.50%, may be particularly preferable in cases where capability of achieving higher hardnesses are prioritized over lower minimum hardness e.g. for purposes of adjustability as described above.
Notwithstanding other material constituents correlated with wear resistance, increased hardness itself is believed correlated in part with greater wear resistance. Thus, the capability of quenching the above steel to achieve a higher hardness in turn may increase wear resistance and strength. This may be particularly true in the case of specific heat treat processes such as laser etching or laser peening in combination with the Carbon contents described above.
The content of Chromium is also believed to contribute to material properties of steel uniquely relevant to golf club heads. This is particularly true regarding hardness and wear resistance, including resistance to rust. Preferably, the content of Chromium present in the steel of club head 100 is selected primarily based on these properties as described below in further detail.
As described above, the club head 100 preferably exhibits a relative high hardness at striking face locations, and relative low hardness at other locations, e.g. the hosel portion 104 and/or the rear portion 116. Chromium, in addition to Nickel and Carbon as described above, may contribute to achieving these desired club head properties. For example, steel composition, apart from its base hardness properties, may dictate which surface processing options, e.g. surface hardening or case hardening, may be effective and their degree of success. For example, in some embodiments, the striking face 102 undergoes a surface hardening process, preferably a nitriding process. in some embodiments, other surface hardening processes may be applied, either in substitution or in addition to nitriding, such ascarburizing, carbonitriding, normalizing, case hardening, induction hardening, cyaniding, flame hardening and laser hardening. However, nitriding is preferable as it is believed to be cost-effective and to achieve the most satisfactory results. Because of the presence of Chromium, a nitriding process is capable of permitting Chromium Nitride to form on the striking face 102. In turn, this permits the striking face 102 to exhibit a surface hardness of no less than 1200 HV (0.05). Otherwise, e.g. for a conventional carbon steel, maximum achievable hardness may be significantly less, e.g. about 800 HV (0.05).
Nitriding may also bear disadvantages. For example, nitriding stainless steel has been shown to decrease corrosion resistance. However, considering the overall use characteristics of a club head, particularly the wedge-type club head 100 of
Regarding rust, preferably the steel composition is adapted to reduce or minimize propagation of rust or natural oxidation. In some alternative embodiments, rusting or oxidizing of the striking face 102 of the club head 100 may be viewed as a positive development. For example, a niche market exists for golf club heads with striking faces exhibiting rust or having characteristics specifically selected to promote rust. Such market of golfers favors the particular texture and/or surface roughness characteristics associated with a rusted face. However, generally, preferably the club head 100 is configured to reduce the onset or propagation of rust. It is believed that club heads susceptible to rust wear faster than club heads not so susceptible. This may be because rust on a striking face is believed to wear faster than regions not exhibiting rust, resulting in a greater rate of volume loss of the rusted club head. This is of particular concern regarding scoreline structure. The presence of Chromium in the steel reduces the onset and propagation of rust, thus likely reducing rate of wear.
Based on the above considerations, the steel implemented in the club head 100 preferably includes Chromium in an amount no less than 13% by mass and more preferably no less than 16% by mass. Additionally, or alternatively, the steel includes Chromium in an amount no greater than 21% by mass, more preferably no greater than 18% by mass. A Chromium content that is too high may frustrate the steel's transition to martensitic crystalline structure, may result in a steel that is too brittle, and may deleteriously result in sigma phase formation during tempering.
In addition to the considerations described above affecting rust reduction and wear, the Chromium contents described above, in association with the described Carbon and Nickel contents, desirably reduce overall steel density. The density of a metallic material is primarily affected by two attributes: (1) the composition of the alloy; and (2) the formation in which its atoms are arranged. A simplified method to estimate the density of an alloy is to take the percent by weight of each constituent element and divide it by the density of the element to return the total volume of each element. Then, assume a 100 g sample and divided by the sum of the volumes, as shown in Equation 1 below:
The other key contributor to steel density is the structure in which the atoms are arranged or the structure's crystal structure. The steel of the club head 100, based on its constituent compositions described above, once tempered and/or quenched, is preferably a mixture of Ferrite, which has body centered cubic structure (BCC), and Martensite- or substantially entirely, or entirely-Martensite. Martensite exhibits body centered tetragonal (BCT) structure in the quenched state and body centered cubic (BCC) structure in the tempered state. Thus, the relative proportions of Martensite's crystal structure is dependent on the amount of tempering after quenching. BCC and BCT structures have an atomic packing factor, i.e. amount of atom volume per unit cell, of 0.68. Because the packing factors for BCC and BCT structures are similar, overall material density is believed primarily governed by composition of the alloy.
Another common metallic crystal structure is face centered cubic (FCC) which has an atomic packing factor greater than BCC or BCT, of 0.74, indicative of a close packed structure. Austenite has an FCC structure so it will generally have a higher density than the blended composition of the steel of the club head 100, even though its calculated density according to the above Equation 1 would be lower. Based on the above, the density of the steel is preferably no greater than 7.85 g/cm2, more preferably no greater than 7.65 g/cm2 and even more preferably no greater than 7.60 g/cm2. Reducing density increases discretionary mass of the club head 100, i.e. mass not primarily required for the structural integrity of the club head thus capable of being intentionally placed in locations for purposes of enhancing the various mass properties of the club head 100, e.g. the location of the center of gravity and moments of inertia about relevant axes passing through the center of gravity.
The constituent composition of Nitrogen in the steel of the club head 100 is also significant. Nitrogen may affect steels in a similar manner as Carbon. This is due to their similar size, i.e. Nitrogen and Carbon may both be considered interstitial elements. For example, Nitrogen is a strong austenite promoter. Thus, increasing Nitrogen composition beyond a certain point may deleteriously result in increased minimum quenched and tempered hardness. Further, if too high in content, Nitrogen may effect partitioning problems of the steel during welding and solidification due to its small size and relatively high diffusion rates. Further, if too high in content, Nitrogen will also effect in steel loss of ductility, undesirable toughness, and corrosion resistance by the formation of CrN. Nitrogen may influence the maximum strength of stainless steels, albeit to a believed lesser extent than Carbon.
Based on the above considerations, the steel of the club head 100 preferably includes Nitrogen content in an amount no greater than 0.035% by mass, more preferably no greater than 0.15% by mass, even more preferably within the range of about 0% to 0.06% by mass. Because of its shared characteristics with Carbon, the combined content of Carbon and Nitrogen also bears significance. Preferably, this combined content in the steel of the club head 100 is within the range of 0.13% to 0.75% by mass, more preferably within the range of 0.20% to 0.35% by mass. In this case, if such content is too low, the steel may not be capable of hardening to a desirable degree, may exhibit reduced wear residence and may exhibit undesirably high density.
The above description details preferable steel composition embodiments for use in golf club head 100. Table 1 below summarizes several exemplary steel compositions corresponding to the above description. Exemplary Steel A corresponds to a first, general example of the steel used in golf club head 100. Exemplary Steel B corresponds to a steel composition according to the above but specifically tailored to embodiments of club head 100 that correspond to hollow body type club heads. Exemplary Steel C corresponds to yet another steel composition according to the above but specifically tailored to embodiments of club head 100 that correspond to forged type iron club heads. 410 SS, 440 SS, 8620 SS and 431 are stainless steel alloys believed to have been known in the golf club industry.
A more detailed assessment of the chemical composition of Exemplary Steel A is shown below in Table #2. Some material properties exhibited by Exemplary Steel A in comparison to known steel alloys are summarized in the chart of
Exemplary Steel B is intended for specific implementation in a hollow-type iron club head. Because of some variation in use and structure, prioritization of material properties and thus material composition varies accordingly relative Exemplary Steel A.
Exemplary Steel C is intended for specific implementation in a forged iron club head. Because of variation in formation and structure, prioritization of material properties and thus material composition varies accordingly relative Exemplary Steel A and Exemplary Steel B. Notably, to accommodate forging, both Chromium content and Carbon content are preferably reduced, e.g. relative to Exemplary Steel A.
Based on the above exemplary embodiments of steel, after quenching, tempering and case hardening, the steel of club head 100 preferably exhibits a maximum hardness of no less than 50HRC, more preferably no less than 55HRC, yet even more preferably within the range of 60HRC and 65HRC. The same steel component of the golf club head 100 preferably includes a minimum hardness of no greater than 90HRB, more preferably no greater than 85HRB. Preferably, the component of the club head 100 comprised of this steel includes a first location on the striking face 102 of the club head 100, preferably a second location at a hosel portion 104, and preferably a third location at a rear portion 116 of the club head. In such embodiments, preferably the first location has a hardness no less than 50HRC more preferably no less than 55HRC, even more preferably within the range of 60HRC to 65HRC. Alternative or additionally, the steel component's maximum hardness preferably coincides with the first location, e.g. is located on the striking face 102. Preferably the second location (and optionally the third location) has a hardness no greater than 90HRB, more preferably no greater than 85HRB. Alternatively or additionally, the steel component's minimum thickness is preferably located on a portion other than the striking face 102, and preferably located at the hosel portion 104. However, in some embodiments the location of minimum hardness of the steel component is on the rear portion 116 or another portion of the club head 100.
In addition or alternatively, a ratio of the maximum hardness of the steel to the minimum hardness of the steel of club head 100 (determined where both maximum and minimum values are expressed in quantities in association with the Rockwell C Hardness (HRV) Scale) is preferably no less than 4.5, more preferably no less than 6, even more preferably no less than 9, yet even more preferably no less than 12. In some particular embodiments, preferably such ratio is within the range of 12 to 16.25.
In step 202, an intermediate club head is formed by casting, e.g. investment or lost-wax casting. Next, optionally, in step 204, welding is applied to add material and/or repair any regions of the intermediate cast club head body due to artifacts or defects of the casting process. For example, welding material may be applied as filler for regions exhibiting porosity issues. The welding material is preferably a stainless steel material. However, other materials may alternatively be used but if so preferably in combination with additional post-processing.
Next, optionally, in step 206, the intermediate club head body is polished preferably removing any remnants of gates or other artifacts resulting from the casting process 202.
Next, in step 208, the intermediate club head body undergoes heat treating 208. Preferably, the heat treating process 208 includes at least a quenching process 208A and a tempering process 208B. Initially, in step 208A, preferably the intermediate club head body is held at a temperature of about 1040° C. for a duration of about 90 min to about 120 min, preferably about 90 min. Subsequently, the intermediate club head body is quenched preferably by immersion in an N2 solution. The result is transition to a harder martensitic structure throughout the majority (i.e. greater than 50%) by mass, more preferably throughout no less than 60% by mass, and even more preferably throughout substantially the entirety of the intermediate club head body.
Next, in step 208B, the intermediate club head body undergoes tempering. In this step, the intermediate club head body is held at a temperature no less than 800° C., more preferably no less than 850° C., even more preferably within the range of 865° C. to 870° C. and yet even more preferably at a temperature of about 870° C. for about 2 hrs. Preferably, subsequently, the intermediate club head body is cooled in an N2 solution. This step tempers the martensite thus softening the intermediate club head body.
In some embodiments, in step 208, the intermediate club head body undergoes plural heat treat cycles. Applying multiple heat treat cycles is preferable in some cases to both maintain a relatively high potential for face hardness of the steel at the striking face 102 and permitting a final club head hardness that is even further reduced at locations including e.g. the hosel portion 104 and/or the rear portion 116. Such plural cycles may include multiple tempering cycles. As shown e.g. in
Next, in step 210, the striking face 102 is preferably surface milled. Next, in step 212, the hosel/neck region of the intermediate club head body is polished to effect a blended appearance between the striking face 102 and the hosel portion 104. Next, in step 214, scorelines are machined into the striking face 102, preferably by milling.
Next, in step 216, the striking face 102 undergoes face hardening. Preferably, the face hardening step 216 includes a nitriding process 216A and additional hardening operations, such as laser hardening or laser peening peening in step 216B.
The step of nitriding 216A occurs at a temperature of preferably no less than about 550° C., more preferably no less than about 575° C., even more preferably at about 580° C., and for a duration of about 50 min. However, alternative or additional face hardening or other protective or cosmetic surface finishing processes are contemplated, such as carburizing, carbonitriding, normalizing, case hardening, induction hardening, cyaniding, flame hardening and coating with PVD, ceramics, and/or diamond). Because of the various constituent compositions described above, the steel applied in the golf club head 100 is believed to exhibit sufficient wear/rust resistance per se, thus not considered to necessitate plating for that purpose. On the other hand, e.g. in the case of 8620 Steel, Nickel and Chromium plating is generally considered necessary for purposes of increasing wear/rust resistance to an acceptable degree.
Preferably, in step 216B, laser hardening is applied to the nitrided striking face. In this step, for a short period of time (e.g. a few seconds) focused heat energy is directed to the striking face 102. Cooling of the striking face 102 subsequent the laser peening process is preferable using e.g. a gas or water. This laser hardening process preferably affects material extending a depth from the striking face 102 of no less than 0.5 mm, more preferably no less than 0.7 mm, even more preferably about 0.8 mm. Such laser hardening process further hardens the striking face 102, e.g. to a hardness of no less than 50HRC, more preferably no less than 52HRC. Based on the above steps, the striking face 102 of the club head 100 preferably achieves hardness and wear resistance values in accordance with embodiments of the club head 100 described above.
As a result of the face hardening process, hardness through the club head 100, more specifically throughout any component comprised of the inventive steels described herein, exhibit a hardness gradient throughout its thickness. Preferably, the club head 100 exhibits martensitic structure at a depth from the striking face (i.e. measured rearward in a direction perpendicular to a virtual striking face plane generally coplanar with the striking face 102) of no less than 50% of the overall depth of the club head 100, more preferably no less than 90% of the overall depth of the club head 100, and even more preferably substantially the entire overall depth of the club head 100. In specific embodiments in which the striking face 102 undergoes nitriding, preferably the nitriding process results in a CrN layer on the striking face 102 of a thickness no less than 0.02 mm, more preferably no less than 0.03 mm, and even more preferably about 0.04 mm.
In the foregoing discussion, the present invention has been described with reference to specific exemplary aspects thereof. However, it will be evident that various modifications and changes may be made to these exemplary aspects without departing from the broader spirit and scope of the invention. It is contemplated that the exemplary steel compositions described herein may be applied in like scenarios, e.g. in use cases known to be functionally similar to the golf club head functionality described herein. For example, such steel compositions may be applied to figure skating or ice skating blades where strength and ductility may be necessary given typical cyclical loading and desirability for forging or cold working. Yet surface hardening may also be beneficial in such cases. Similarly, such steel compositions may be applied to edges used in skis, snowboards, and related snow-glideable equipment for similar reasons. Particularly in the case of snow-glideable equipment, such edges must exhibit sufficient malleability to be formed about irregular or complex perimetric shapes yet exhibit sufficient surface hardness and wear resistance/rust resistance given their expected repeated interaction with snow and ice. Accordingly, the foregoing discussion and the accompanying drawings are to be regarded as merely illustrative of the present invention rather than as limiting its scope in any manner.
This application is a non-provisional of U.S. Provisional Application No. 63/614,154, filed on Dec. 22, 2023, the disclosure of which is incorporated herein by reference in its entirety.
| Number | Date | Country | |
|---|---|---|---|
| 63614154 | Dec 2023 | US |
