BLADE FOR A RECIPROCATING SAW

Abstract

A blade is usable with a reciprocating saw imparting movement to the blade in a forward direction and a rearward direction to perform a cutting operation on a workpiece. The blade includes an attachment portion configured to couple to the reciprocating saw and a body extending from the attachment portion. The body includes a first profile portion and a second profile portion extending from the first profile portion. The second profile portion has a height less than a height of the first profile portion. The blade also includes a plurality of teeth formed on the body and defining a toothed cutting edge. The blade also includes a tip portion formed at a distal end of the second profile portion and terminating in a pointed tip. The pointed tip is configured to punch a hole through the workpiece and includes a toothless cutting edge extending substantially parallel to the toothed cutting edge. The toothless cutting edge extends from the toothed cutting edge to the pointed tip.

Description

FIELD OF THE INVENTION

The present invention relates to blades for power tools, and more particularly to a blade for a reciprocating saw.

BACKGROUND OF THE INVENTION

Reciprocating tools, such as reciprocating saws, typically include removable blades to allow for replacement of worn or damaged blades.

SUMMARY

The invention provides, in one aspect, a blade for use with a reciprocating saw imparting movement to the blade in a forward direction and a rearward direction to perform a cutting operation on a workpiece. The blade includes an attachment portion configured to couple to the reciprocating saw and a body extending from the attachment portion. The body includes a first profile portion and a second profile portion extending from the first profile portion. The second profile portion has a height less than a height of the first profile portion. The blade also includes a plurality of teeth formed on the body and defining a toothed cutting edge. The blade also includes a tip portion formed at a distal end of the second profile portion and terminating in a pointed tip. The pointed tip is configured to punch a hole through the workpiece and includes a toothless cutting edge extending substantially parallel to the toothed cutting edge. The toothless cutting edge extends from the toothed cutting edge to the pointed tip.

The invention provides, in another aspect, a reciprocating saw including a housing, a motor supported by the housing, and a blade clamp mechanism supported for reciprocating motion relative to the housing. The reciprocating saw also includes a drive mechanism connected between the motor and the blade clamp mechanism to impart reciprocating motion to the blade clamp mechanism and a blade. The blade includes an attachment portion coupled to the blade clamp mechanism and a body extending from the attachment portion. The body includes a first profile portion and a second profile portion extending from the first profile portion. The second profile portion has a height less than a height of the first profile portion. The blade also includes a plurality of teeth formed on the body and defining a toothed cutting edge. The blade also includes a tip portion formed at a distal end of the second profile portion and terminating in a pointed tip. The pointed tip is configured to punch a hole through the workpiece. The tip portion includes a toothless cutting edge extending substantially parallel to the toothed cutting edge, and the toothless cutting edge extends from the toothed cutting edge to the pointed tip.

Other features and aspects of the invention will become apparent by consideration of the following detailed description and accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a side view of a reciprocating power tool for receiving a blade according to an embodiment of the invention, shown in FIG. 1 receiving a saw blade.

FIG. 2 is a cross-section of the reciprocating power tool shown in FIG. 1 and including a shoe.

FIG. 3 is a profile view of a blade according to an embodiment of the invention.

FIG. 4A is an enlarged view of a toothed portion of the blade shown in FIG. 3.

FIG. 4B is another enlarged view of the toothed portion of the blade shown in FIG. 3.

FIG. 5 is a profile view of a blade according to another embodiment of the invention.

FIG. 6 is an enlarged view of a toothed portion of the blade shown in FIG. 5.

FIG. 7 is a profile view of a blade according to another embodiment of the invention.

Before any embodiments of the invention are explained in detail, it is to be understood that the invention is not limited in its application to the details of construction and the arrangement of components set forth in the following description or illustrated in the following drawings. The invention is capable of other embodiments and of being practiced or of being carried out in various ways. Also, it is to be understood that the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting.

DETAILED DESCRIPTION

FIGS. 1 and 2 illustrate a reciprocating power tool 10 including a blade clamp mechanism 12. The illustrated reciprocating power tool 10 is a reciprocating saw; however, in other embodiments, other reciprocating power tools may include the invention. As shown in FIGS. 1 and 2, the power tool 10 includes a saw housing 14 having a forward portion 16, a body portion 18 housing a motor 20 (FIG. 2), and a handle portion 22. The forward portion 16 of the saw housing 14 includes a blade receiving aperture or end 24 that receives a saw blade 26 (FIG. 1), a blade 46 (FIGS. 3-4B) according to one embodiment of the invention, a blade 46′ (FIGS. 5-6) according to another embodiment of the invention, or a blade 46″ (FIG. 7) according to another embodiment of the invention, as will be described in greater detail below. The saw blade 26, 46, 46′, 46″ is releasably coupled to the blade clamp mechanism 12 (FIG. 2) positioned within the saw housing 14, specifically, within the receiving aperture 24. In the illustrated embodiment, a boot or grip portion 28 is positioned over the forward portion 16 of the saw housing 14. In this embodiment, the boot 28 provides a grip area 30 for the user and/or provides protection to the tool 10. In some embodiments, the boot 28 is over-molded onto the forward portion 16. The handle portion 22 includes an over-mold to define an ergonomic grip 32 and allows a user to hold and control the power tool 10.

With continued reference to FIGS. 1 and 2, the power tool 10 includes a trigger-type power switch 34 for activating a power supply 36 of the tool 10 and a button or switch 38 for selecting a speed level (e.g., a high speed or a low speed) for reciprocating the saw blade. In the illustrated embodiment, the power supply 36 is a rechargeable battery pack. The battery pack 36 is releasably coupled to the handle portion 22 to provide power to the power tool 10, and is releasable away from and rearward of the handle portion 22. In the illustrated embodiment, the battery pack 36 is an eighteen-volt (18V) rechargeable power tool battery pack. In other embodiments, the battery pack 36 may be a twelve-volt (12V), a twenty-four-volt (24V), or other various voltages. According to another embodiment, the power supply 36 may be an alternating current (AC) power provided via a corded plug electrically coupled to a wall outlet or any number of suitable powering options.

With reference to the cross section illustrated in FIG. 2, the reciprocating tool 10 also includes a drive mechanism 40 positioned substantially within the housing 14. The drive mechanism 40 is coupled to the motor 20 and to a spindle 42 for transferring rotational motion of a shaft of the motor 20 into reciprocating motion of the spindle 42 along a longitudinal axis X relative to the housing 14. The blade clamp mechanism 12 is disposed at a distal end of the spindle 42 for receiving the blade. The blade clamp mechanism 12 secures the blade to the spindle 42 for reciprocation with the spindle 42 in a direction R (FIG. 1), which is substantially parallel to the longitudinal axis X. In other embodiments, other suitable types and configurations of blade clamp mechanisms may be employed.

The reciprocating tool 10 also includes a removable shoe 44, illustrated in FIG. 2, operable to engage a work piece and provide stability to the tool 10 while cutting. The shoe 44 may be removed when the blade is attached to the blade clamp mechanism 12. The shoe 44 typically acts as a stop to limit the depth of the saw blade 26 into the workpiece and to prevent the workpiece from engaging the saw blade 26 at a connection of the saw blade 26 to the tool 10, e.g., at the blade clamp mechanism 12. In some embodiments, the shoe 44 freely pivots about an axis to allow the user to adjust an angle at which the blade 26 engages the workpiece during a cut. In some embodiments, the reciprocating tool 10 may not include a shoe.

In other embodiments, the power tool 10 may include various handle constructions, drive mechanisms, blade clamp mechanisms, and power configurations. In further embodiments, the power tool 10 may include other types of power and speed control switches or may not include a speed control feature.

FIGS. 3-4B illustrate the blade 46 according to an embodiment of the invention. The blade 46 is preferably formed from a bi-metal strip, or any hardened steel, and includes an attachment portion 48 and a body 50 extending from the attachment portion 48. The attachment portion 48 includes a tang 52 and an aperture 54, which are configured to engage with the blade clamp mechanism 12 to securely and releasably connect the blade 46 to the reciprocating tool 10. The attachment portion 48 defines a longitudinal axis A that, when attached to the blade clamp mechanism 12, is substantially parallel to the longitudinal axis X of reciprocation of the spindle 42. In some embodiments, the longitudinal axis A is coincident with the longitudinal axis X when the blade 46 is attached to the blade clamp mechanism 12. In other embodiments, other types or configurations of attachment portions may be employed in order to suit the blade clamp mechanism 12 of the reciprocating tool 10. In yet other embodiments, other suitable materials may be used to form the blade 46.

The body 50 includes a tall profile portion 56 extending from the attachment portion 48, a low profile portion 58 extending from the tall profile portion 56, and a cutting edge 60 extending across the tall profile portion 56 and the low profile portion 58. The cutting edge 60 extends substantially along a cutting plane B. The attachment portion 48 is angled with respect to the cutting edge 60 (and the cutting plane B) by a tang angle C. The tang angle C is preferably between about 0 degrees and about 6.5 degrees. In some embodiments, the tang angle C is higher, e.g., about 25 degrees. Therefore, in some embodiments, the tang angle C is between about 0 degrees and about 25 degrees. The cutting edge 60, which may also be referred to as a toothed cutting edge 60, includes teeth 62, which are best illustrated in the enlarged view of FIG. 4A. Preferably, there are between about 18 teeth per inch and about 40 teeth per inch along the cutting edge 60. In the illustrated embodiment, there are about 30 teeth per inch. The teeth 62 have a fine-pitched V-shaped tooth form.

FIGS. 4A and 4B illustrate the teeth 62 in greater detail. Each tooth includes an angle D and an angle E with respect to the cutting edge 60 (and cutting plane B). The angle D is preferably between about 30 and about 70 degrees. The angle E is preferably between about 30 and about 70 degrees. In the illustrated construction, the angle D is about 57 degrees and the angle E is about 53 degrees. The angle E is sometimes referred to as the relief angle. A rake angle is sometimes defined as the measurement of angle D minus 90 degrees, e.g., −33 degrees in the illustrated embodiment. The tooth form also includes gullets 66 having a radius R. The radius R is preferably between about 0.005 and about 0.020 inches. In the illustrated construction, the radius R is about 0.008 inches. Each gullet 66 is spaced from an adjacent gullet 66 by a distance, or pitch, K measured parallel to the cutting edge 60, or cutting plane B. Preferably, the pitch K is between about 0.025 and about 0.055 inches. In the illustrated embodiment, the pitch K is about 0.033 inches. The teeth 62 also have a tooth height M, defined between the tip of the teeth 62 and the peak of the gullets 66. Preferably, the tooth height M is between about 0.010 and about 0.035 inches. The tooth height M is about 0.017 inches in the illustrated embodiment.

A distal end of the blade 46 terminates in a pointed tip 64 located adjacent the cutting teeth 62 at a distal end of the toothed cutting edge 60. The pointed tip 64 is sharp and allows the blade 46 to puncture a workpiece. A toothless cutting edge 65 extends parallel to the toothed cutting edge 60, from the distal end of the toothed cutting edge 60 to the pointed tip 64. The toothless cutting edge 65 allows the pointed tip 64 to puncture the workpiece without catching or binding. The pointed tip 64 includes a tip angle H of about 15 degrees to about 45 degrees. The tip angle H is about 30 degrees in the illustrated embodiment. In the illustrated embodiment, the body 50 is formed as one piece with the attachment portion 48. In other embodiments, fasteners or fastening means may be employed, such as rivets, screws, bolts, glue, adhesives, welding, soldering and the like.

The blade 46, and more specifically, the body 50, has a material thickness of about 0.035 inches to about 0.080 inches. The overall length L of the blade 46 is between about 2.75 inches and about 4.5 inches. A length G of the low profile portion 58 is between about 1.5 inches and about 3 inches. A height F of the low profile portion 58 is between about 0.25 inches and about 0.625 inches.

FIGS. 5-6 illustrate a blade 46′ according to another embodiment of the invention. The blade 46′ is preferably formed from a bi-metal strip, or any hardened steel, and includes an attachment portion 48 and a body 50 extending from the attachment portion 48, a tang 52, an aperture 54, a longitudinal axis A, a tall profile portion 56′ extending from the attachment portion 48, a low profile portion 58′ extending from the tall profile portion 56′, a cutting edge 60, a cutting plane B, and a pointed tip 64, which are described in greater detail above with respect to the blade 46. Like features, accordingly, are labeled the same as those above and need not be described in detail again.

The low profile portion 58′ is longer than the low profile portion 58 described above, measured in a direction parallel to the cutting edge 60. The tall profile portion 56′ is shorter than the tall profile portion 56 described above, measured in a direction perpendicular to the cutting edge 60. Specifically, the low profile portion 58′ has a length G′, measured from the junction with the tall profile portion to the tip 64, preferably between about 1.6 inches and about 2.5 inches. In the illustrated construction, the length G′ is about 2.4 inches. The tall profile portion 56′ has a length N, measured from the center of the aperture 54 to the junction with the low profile portion 58′, preferably between about 0.43 to about 1.27 inches. In the illustrated construction, the length N is about 0.53 inches. Thus, a ratio of the length N of the tall profile portion to the length G′ of the low profile portion is between about 0.17 and about 0.79 (and is preferably about 0.22). Accordingly, the tall profile portion 56′ does not extend as far away from the tang 52 as in the embodiment shown in FIGS. 3-4 such that the tall profile portion 56′ does not pass the shoe 44 of the reciprocating tool 10.

The blade 46′ also includes a toothless cutting edge 65 that extends parallel to the cutting edge 60, from the distal end of the cutting edge 60 to the pointed tip 64. The toothless cutting edge 65 defines a tip length J. Accordingly, the teeth 62′ are spaced from the pointed tip 64 by a distance equal to the tip length J. The tip length J is preferably between about 0.15 and about 0.30 inches. In the illustrated embodiment, the tip length J is about 0.23 inches.

The blade 46′ also includes some geometry that is substantially the same as the geometry described above and, accordingly, is labeled the same and need not be described again in detail. Specifically, the blade 46′ includes the overall length L, the height F of the low profile portion 58, the tang angle C, and the tip angle H. In the illustrated embodiment, the overall length L is about 3.33 inches (and preferably between about 2.75 to about 4.5 inches, as described above). Thus, a ratio of the length G′ of the low profile portion 58′ to the overall length L is between about 0.35 and about 0.91 (and is about 0.72 in the illustrated embodiment). The height F of the low profile portion is about 0.25 inches (and is preferably between about 0.25 to about 0.625 inches as described above). The tang angle C is preferably between about 0 and about 10 degrees. The tip angle H is about 30 degrees (and preferably between about 15 to about 45 degrees, as described above).

The cutting edge 60 of the blade 46′ includes cutting teeth 62′. FIG. 6 illustrates the tooth form of the cutting teeth 62′ in greater detail. In the illustrated construction, the cutting edge 60 includes about 30 teeth per inch. The teeth 62′ have a fine-pitched V-shaped tooth form. Each tooth includes an angle D′ and an angle E′ with respect to the cutting edge 60 (and cutting plane B). The angle D′ is preferably between about 30 and about 70 degrees. The angle E′ is preferably between about 30 and about 70 degrees. In the illustrated construction, the angle D′ is about 57 degrees and the angle E′ is about 50 degrees. The angle E′ is sometimes referred to as the relief angle. A rake angle is sometimes defined as the measurement of angle D′ minus 90 degrees, e.g., −33 degrees in the illustrated embodiment. The tooth form also includes gullets 66′ having a radius R′. The radius R′ is preferably between about 0.005 and about 0.020 inches. In the illustrated construction, the radius R′ is about 0.008 inches. Each gullet 66′ is spaced from an adjacent gullet 66′ by a distance, or pitch, K′ measured parallel to the cutting edge 60, or cutting plane B. Preferably, the pitch K′ is between about 0.025 and about 0.055 inches. In the illustrated embodiment, the pitch K′ is about 0.033 inches. The teeth 62′ also have a tooth height M′, defined between the tip of the teeth 62′ and the peak of the gullets 66′. Preferably, the tooth height M′ is between about 0.010 and about 0.035 inches. The tooth height M′ is about 0.017 inches in the illustrated embodiment.

FIG. 7 illustrates a blade 46″ according to another embodiment of the invention. The blade 46″ is substantially similar to the blade 46′ shown in FIGS. 5-6 and like parts are labeled with like numerals and need not be described again. The blade 46″ includes a tall profile portion 56″ and a low profile portion 58″. The low profile portion 58″ includes steps 68 disposed between the tall profile portion 56″and the pointed tip 64.

The blade 46, 46′, 46″ is particularly well-suited for cutting duct material in heating, ventilation and air conditioning (HVAC) applications. In operation, a user attaches the blade 46, 46′, 46″ to the blade clamp mechanism 12 of the reciprocating power tool 10 and manually jams the pointed tip 64 into the material, similar to stabbing the material with a bayonet. The short length L of the blade 46, 46′, 46″ and the sharp pointed tip 64 allow the blade 46, 46′, 46″ to be plunged into duct material with reduced force and without substantial bending. In addition, the toothless cutting edge 65 of the tip 64 prevents the blade 46, 46′, 46″ from catching or binding when it is jammed into the material. The blade 46, 46′, 46″ is long enough so that it may remain in the cut during both the back and forward strokes. Specifically, the low profile portion 58 performs the cut and remains in the material during the back and forward strokes. Once in the material, the blade 46, 46′, 46″ cuts with a reciprocating action imparted by the reciprocating power tool 10. The fine-pitched V-shaped tooth form of the teeth 62 cuts the material in both directions and reduces vibration in the duct material during cutting. The low profile section 58 allows tight radius cuts in the duct material.

Thus, the invention provides, among other things, a blade attachable to a reciprocating saw for making tight radius cuts in HVAC duct material. Various features of the invention are set forth in the following claims.

Claims

1. A blade for use with a reciprocating saw imparting movement to the blade in a forward direction and a rearward direction to perform a cutting operation on a workpiece, the blade comprising: an attachment portion configured to couple to the reciprocating saw;a body extending from the attachment portion, the body including a first profile portion and a second profile portion extending from the first profile portion, wherein the second profile portion has a height less than a height of the first profile portion;a plurality of teeth formed on the body and defining a toothed cutting edge; anda tip portion formed at a distal end of the second profile portion and terminating in a pointed tip configured to punch a hole through the workpiece, the tip portion including a toothless cutting edge extending substantially parallel to the toothed cutting edge, wherein the toothless cutting edge extends from the toothed cutting edge to the pointed tip.

2. The blade of claim 1, wherein the tip portion includes a tip length between about 0.15 inches and about 0.30 inches.

3. The blade of claim 2, wherein the tip length is about 0.23 inches.

4. The blade of claim 1, wherein the plurality of teeth includes between about 18 teeth per inch and about 40 teeth per inch.

5. The blade of claim 4, wherein the plurality of teeth includes about 30 teeth per inch.

6. The blade of claim 1, wherein each tooth includes a tip, the tips collectively defining the toothed cutting edge, and wherein the blade includes a plurality of gullets formed between adjacent teeth, each gullet including a peak.

7. The blade of claim 6, wherein each peak includes a radius between about 0.005 and about 0.020 inches.

8. The blade of claim 7, wherein the radius is about 0.008 inches.

9. The blade of claim 6, wherein each tooth includes a tooth height between about 0.01 inches and about 0.035 inches, measured substantially perpendicular to the toothed cutting edge from the tip of the tooth to the peak of a gullet adjacent the tooth.

10. The blade of claim 9, wherein the tooth height is about 0.017 inches.

11. The blade of claim 1, wherein the blade includes an overall length between about 2.75 inches and about 4.50 inches, measured substantially parallel to the toothed cutting edge from a proximal end of the attachment portion to the pointed tip.

12. The blade of claim 11, wherein the overall length is about 3.33 inches.

13. The blade of claim 1, wherein the second profile portion includes a profile length between about 1.5 inches and about 3.0 inches, measured substantially parallel to the toothed cutting edge from the first profile portion to the pointed tip.

14. The blade of claim 13, wherein the profile length is about 2.4 inches.

15. The blade of claim 1, wherein the first profile portion includes a profile length between about 0.43 inches and about 1.27 inches, measured substantially parallel to the toothed cutting edge from an attachment point on the attachment portion to the second profile portion.

16. The blade of claim 15, wherein the profile length is about 0.53 inches.

17. The blade of claim 1, wherein the blade includes an overall length measured substantially parallel to the toothed cutting edge from a proximal edge of the attachment portion to the pointed tip, and the second profile portion includes a profile length, and wherein a ratio of the profile length to the overall length is between about 0.35 and about 0.91.

18. The blade of claim 17, wherein the ratio of the profile length to the overall length is about 0.72.

19. The blade of claim 17, wherein the blade includes a first profile length measured substantially parallel to the toothed cutting edge from an attachment point of the attachment portion to the second profile portion, and wherein a ratio of the first profile length to the profile length is between about 0.17 and about 0.79.

20. The blade of claim 19, wherein the ratio of the first profile length to the profile length is about 0.22.

21. The blade of claim 1, wherein the height of the second profile portion is between about 0.25 inches and about 0.625 inches.

22. The blade of claim 21, wherein the height of the second profile portion is about 0.25 inches.

23. The blade of claim 1, wherein the body includes a stepped transition portion between the first profile portion and the second profile portion, the stepped transition portion having a height less than the height of the first profile portion and greater than the height of the second profile portion.

24. The blade of claim 1, wherein the pointed tip and the toothless cutting edge define an angle between about 15 degrees and about 45 degrees.

25. The blade of claim 24, wherein the angle is about 30 degrees.

26. The blade of claim 1, wherein at least one of the plurality of teeth includes a front edge defining a relief angle with the toothed cutting edge, and wherein the relief angle is between about 30 degrees and about 70 degrees.

27. The blade of claim 26, wherein the relief angle is about 50 degrees.

28. The blade of claim 1, wherein at least one of the plurality of teeth includes a back edge defining an angle with the toothed cutting edge, and wherein the angle is between about 30 degrees and about 70 degrees.

29. The blade of claim 28, wherein the angle is about 57 degrees.

30. The blade of claim 1, wherein the blade is formed from a bi-metal strip.

31. A reciprocating saw comprising: a housing;a motor supported by the housing;a blade clamp mechanism supported for reciprocating motion relative to the housing;a drive mechanism connected between the motor and the blade clamp mechanism to impart reciprocating motion to the blade clamp mechanism; anda blade including an attachment portion coupled to the blade clamp mechanism;a body extending from the attachment portion, the body including a first profile portion and a second profile portion extending from the first profile portion, wherein the second profile portion has a height less than a height of the first profile portion;a plurality of teeth formed on the body and defining a toothed cutting edge; anda tip portion formed at a distal end of the second profile portion and terminating in a pointed tip, the pointed tip configured to punch a hole through the workpiece, the tip portion including a toothless cutting edge extending substantially parallel to the toothed cutting edge, wherein the toothless cutting edge extends from the toothed cutting edge to the pointed tip.

32. The reciprocating saw of claim 31, wherein the tip portion includes a tip length of about 0.23 inches.

33. The reciprocating saw of claim 31, wherein the plurality of teeth includes about 30 teeth per inch.

34. The reciprocating saw of claim 31, wherein the blade includes an overall length of about 3.33 inches, measured substantially parallel to the toothed cutting edge from a proximal edge of the attachment portion to the pointed tip.

35. The reciprocating saw of claim 31, wherein the second profile portion includes a profile length of about 2.4 inches, measured substantially parallel to the toothed cutting edge from the first profile portion to the pointed tip.

36. The reciprocating saw of claim 31, wherein the first profile portion includes a first profile length of about 0.53 inches, measured substantially parallel to the toothed cutting edge from an attachment point on the attachment portion to the second profile portion.

37. The reciprocating saw of claim 31, wherein the blade includes an overall length measured substantially parallel to the toothed cutting edge from a proximal edge of the attachment portion to the pointed tip, and the second profile portion includes a profile length, and wherein a ratio of the profile length to the overall length is about 0.72.

38. The reciprocating saw of claim 37, wherein the blade includes a first profile length measured substantially parallel to the toothed cutting edge from an attachment point of the attachment portion to the second profile portion, and wherein a ratio of the first profile length to the profile length is about 0.22.

39. The reciprocating saw of claim 31, wherein the height of the second profile portion is about 0.25 inches measured substantially perpendicular to the toothed cutting edge.

40. The reciprocating saw of claim 31, wherein the body includes a stepped transition portion between the first profile portion and the second profile portion, the stepped transition portion having a height less than the height of the first profile portion and greater than the height of the second profile portion.

41. The reciprocating saw of claim 31, wherein the pointed tip and the toothless cutting edge define an angle of about 30 degrees.

42. The reciprocating saw of claim 31, wherein at least one of the plurality of teeth includes a front edge defining a relief angle with the toothed cutting edge, and wherein the relief angle is about 50 degrees.

43. The reciprocating saw of claim 31, wherein at least one of the plurality of teeth includes a back edge defining an included angle with the toothed cutting edge, and wherein the included angle is about 57 degrees.