WO2005096949A2

WO2005096949A2 - Tooth form design for reciprocating saw blade

Info

Publication number: WO2005096949A2
Application number: PCT/US2005/009879
Authority: WO
Inventors: Rickey J. Thomas; Leonard R. Baublitz; David S. Bruner; Malek George; Markus Rompel; Russell J. Bohart
Original assignee: Black & Decker Inc.
Priority date: 2004-03-26
Filing date: 2005-03-24
Publication date: 2005-10-20
Also published as: EP1727470A2; WO2005096949B1; AU2005231308A1; EP1727470A4; WO2005096949A3

Abstract

A reciprocating saw has a tooth form that decreases the cutting time of the saw blade and extends the life of the saw blade. The tooth height is longer than conventional metal cutting reciprocating saws. Also, the tooth form has a larger gullet. The tooth rake angle remains substantially constant during the life of the saw blade.

Description

TOOTH FORM DESIGN FOR RECIPROCATING SAW BLADE

BACKGROUND OF THE INVENTION [0001] The present invention relates to saw blades and, more particularly, to a tooth form for reciprocating saw blades for reciprocating jig, or saber saws as well as hole saw blades. [0002] Reciprocating saws are utilized to cut metallic and wooden materials. Ordinarily, when utilizing a reciprocating saw blade, the user generally looks at various aspects of the saw blade. When choosing a reciprocating saw blade, the user considers the expectant life of the saw blade; how many cuts before saw blade replacement occurs. Secondly, the user is concerned with the speed of the saw blade, how fast the saw blade cuts through the material. Next the user considers the durability of the saw blade; how long it will last under normal wear and tear. Finally, the user is concerned with the accuracy of the saw blade; how well will the saw blade follow its intended line of cut. [0003] The present invention provides the art with a reciprocating saw blade utilized for cutting a metallic material. The saw blade increases the life of the saw blade as well as the speed of cut of the saw blade. [0004] The present invention provides the art with a saw blade which reduces the moment and stress on the tooth. The present invention reduces the impact on the tooth by reducing the pitch between teeth. This also provides a larger number of teeth on smaller diameter saws. The present invention provide teeth with various gullet depth. The tooth pattern enables pairs of teeth to be provided with additional reinforcement. [0005] According to the present invention, a reciprocating saw blade comprises a rake face having a first end forming a tip and a second end being continuous with a first gullet. A relief face extends from the tip of the rake face and is continuous with a second gullet. The rake face defines a relief angle of between about 38° to about 50°. The rake face and the relief face define an included angle of about 40° to about 50°. The rake face has a desired tooth depth wherein the tooth depth is about 30% to 70% of the maximum gullet depth and about 18% to 77% of a pitch length. The first and second gullet have a radius of about 30% to 70% of the maximum gullet depth. Also, the rake face has an angle from about 0° to about 3°. The relief angle is about 40° to 46° and the included angle is about 44° to 50°. [0006] According to a second aspect of the invention, a reciprocating blade has a plurality of teeth comprising teeth having a tooth form including a rake face with a first end forming a tip and a second end being continuously with a first gullet. A relief face extend from the tip of the rake face and is continuous with a second gullet. The relief face defines a relief angle of between about 38° to about 50°. The rake face and the relief face define an included angle from about 40° to 50°. The rake face has a desired tooth depth such that the tooth depth is about 30% to 70% of a maximum gullet depth and about 18% to 77% of the pitch depth. The saw blade includes set and unset teeth wherein the unset tooth is considered a raker tooth. In one embodiment, the relief angle is between 40° to 50°, the included angle between 40° to 50°, the tooth depth about 30% to 70% of a maximum gullet, and about 50% to 77% of a pitch length. In another embodiment, the relief angle is between 38° to 42°, the included angle between 45° to 50°, the tooth depth about 30% to 70% of a maximum gullet, and between 18% to 26% of a pitch length. [0007] According to the third aspect of the invention, a saw blade comprises teeth having first and second repeating tooth forms. The first tooth form has a first rake face on an angle from about 0° to 3°. A relief face is adjacent to the rake face to form a cutting edge. The relief face is at an angle of about 30° to 40°. A first gullet is continuous with the relief face. The gullet has a desired depth such that the first tooth form has a first height. The second tooth form has a second rake face continuous with the first gullet. The second rake face defines a rake angle from about 0° to 3°. The second relief face is adjacent the second rake face to form a cutting edge. The second relief face is on an angle from about 30° to 40°. The second gullet is continuous with the second relief face. The second gullet has a desired depth such that the second tooth form has a second tooth height. The second tooth height is greater than the first tooth height. Ordinarily, the first and second relief angles as well as the first and second rake angles are the same. The cutting edges of the first and second tooth forms are substantially at the same height. The first and second tooth forms form a repeating pattern with set or unset or both teeth. [0008] According to the fourth aspect of the invention, a saw blade comprises teeth having first and second repeating tooth forms. The first tooth form has a first rake face on an angle from about 5° to 12°. A relief face is adjacent to the rake face to form a cutting edge. The relief face is at an angle of about 30° to 40°. A first gullet is continuous with the relief face. The gullet has a desired depth such that the first tooth form has a first height. The second tooth form has a second rake face continuous with the first gullet. The second rake face defines a rake angle from about 5° to 12°. The second relief face is adjacent the second rake face to form a cutting edge. The second relief face is on an angle from about 30° to 40°. The second gullet is continuous with the second relief face. The second gullet has a desired depth such that the second tooth form has a second tooth height. The second tooth height is greater than the first tooth height. Ordinarily, the first and second relief angles as well as the first and second rake angles are the same. The cutting edges of the first and second tooth forms are substantially at the same height. The first and second tooth forms form a repeating pattern with set or unset or both teeth. [0009] From the following detailed description taken in conjunction with the attached drawings and claims, other objects and advantages of the present invention will become apparent to those skilled in the art.

BRIEF DESCRIPTION OF THE DRAWINGS [0010] Figure 1 is a side view of a reciprocating saw blade in accordance with the present invention. [0011] Figure 2 is an enlarged side view of a tooth form in accordance with the present invention. [0012] Figure 3 is an enlarged top plan view of a portion of the saw blade of Figure 1. [0013] Figure 4 is a schematic view of a tooth form of the present invention. [0014] Figure 5 is a schematic view of a tooth form of the present invention. [0015] Figure 6 is a side view of a reciprocating saw blade in accordance with a second embodiment of the present invention. [0016] Figure 7 is an enlarged side view of a tooth form in accordance with the present invention. [0017] Figure 8 is an enlarged top plan view of a portion of the saw blade of Figure 6. [0018] Figure 9 is a side view of a reciprocating saw blade in accordance with a third embodiment of the present invention. [0019] Figure 10 is a enlarge side view of a tooth form in accordance with the present invention. [0020] Figure 11 is an enlarged top plan view of a portion of the saw blade of Figure 9. [0021] Figure 12 is a perspective view of a holesaw in accordance with the present invention. [0022] Figure 13 is a side elevational view of a portion of the cutting edge of the holesaw of Figure 12. [0023] Figure 14 is a plan view of a tooth pattern in accordance with the invention. [0024] Figure 15 is a plan view of a second tooth pattern in accordance with the present invention. [0025] Figure 16 is a plan view of a third tooth pattern of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT [0026] Turning to the figures, a reciprocating saw blade is illustrated and designated with the reference numeral 10. The saw blade 10 includes a body 12, a connecting portion 14, and a cutting portion 16. The cutting portion 16 includes a plurality of teeth 18. The teeth 18 can have a raker style set wherein a first tooth is neutral or in the plane of the body with a second tooth offset to the left and a third tooth offset to the right with a repeating pattern as seen in Figure 3. [0027] Turning to Figure 2, an enlarged tooth form is illustrated. The tooth 18 has a rake face 22 and a relief face 24. The rake face 22 is perpendicular to the horizon and thus is a zero angle rake face. The rake face

22 or land has a tooth depth identified by the numeral 26. The relief face 24 is defined by a relief angle of between forty to fifty degrees. Preferably, the relief angle is between forty-four to forty-six degrees. The relief face 24 is continuous with a curved portion 28 of the gullet 30. [0028] The relief face 24 and rake face 22 define an included angle β,

The angle of the included angle is between 40° to 50°. Preferably, the included angle is 44° to 46°. [0029] The gullet 30 has a radius defined by the numeral 32. The tooth depth 26 and the gullet radius 32 defines the maximum gullet depth or tooth height 34. The pitch, designated with the reference numeral 36, is the distance between the tips of adjacent teeth. The present invention is especially applicable to a reciprocating saw blade having 18 teeth per inch. [0030] The tooth depth 26 is a length from the tip of the tooth 18 to the curved portion 28 of the gullet 30. The tooth depth 26 has a length from about 30% to about 70% of the tooth height or maximum gullet depth. Preferably, the tooth depth is between 50% to 70% of the tooth height or maximum gullet depth. [0031] The gullet radius 32 has a length between 30% to 70% of the length of the tooth height or maximum gullet depth 34. Preferably, the gullet radius 32 length is between 30% to 50% of the length of the tooth height or maximum gullet length. Also, the gullet radius 32 is between 15% to 27% of the length of the pitch 36. Preferably, the gullet radius 32 is between 20% to 25% of the length of the pitch 36. [0032] The present tooth form is substantially longer than current teeth forms used for metal cutting reciprocating blades. The tooth height length is between 50% to 77% of the length of the pitch length. Preferably, the tooth height has a length between 65% to 75% of the pitch length in this particular case the pitch length is 1.41 mm. [0033] Turning to Figures 6-8, a reciprocating saw blade is illustrated and designated with the reference numeral 110. The saw blade 110 includes a body 112, a connecting portion 114, and a cutting portion 116. The cutting portion 116 includes a plurality of teeth 118. The teeth 118 can have a raker style set wherein a first tooth is neutral or in the plane of the body with a second tooth offset to the left and a third tooth offset to the right with a repeating pattern. [0034] Turning to Figure 7, an enlarged tooth form is illustrated. The tooth 118 has a rake face 122 and a relief face 124. The rake face 122 is ordinarily perpendicular to the horizon and thus is a zero angle rake face.

However, the rake angle may be modified up to a 3° rake face angle. The rake face 122 or land has a tooth depth identified by the numeral 126. The relief face

124 is defined by a relief angle α of between 38°-42°. Preferably, the relief angle is about 40°. The relief face 124 is continuous with a curved portion 128 of the gullet 130. [0035] The tooth form has a desired included angle β of between 45° to 50°. The included angle β preferably is between 47° to 50°. The increase in the included angle provides the tooth with additional mass which, in turn, increases the strength of the tooth. [0036] The gullet 130 has a radius defined by the numeral 132. The tooth depth 126 and the gullet radius 132 defines the maximum gullet depth or tooth height 134. The pitch, designated with the reference numeral 136, is the distance between the tips of adjacent teeth. [0037] Rake length 126 is a length from the tip of the tooth 118 to the curved portion 132 of the gullet 130. Rake length 126 has a length from about

30% to about 50% of the tooth height or maximum gullet depth. Preferably, the tooth depth is between 38% to 46% of the tooth height or maximum gullet depth. [0038] The gullet deepest point, defined by radius 132, has a length between 50% to 55% of the length of the tooth height or maximum gullet depth

134. Preferably, the radius 132 length is between 52% to 55% of the length of the tooth height or maximum gullet length. Also, the radius 132 is between 20% the length of the pitch 136. [0039] The tooth design has a second radius 128 starting on the maximum depth of the gullet to the relief face. This radius increases the material on the tooth base, reduces stress and adds durability to the tooth. [0040] The present tooth form is longer than current teeth forms used for metal cutting reciprocating blades. The tooth depth length is between 45% to 55% of the length of the pitch length. Preferably, the tooth depth has a length between 49% to 52% of the pitch length. Also, the gullet has a larger area and a more round arc than current teeth forms used for metal cutting reciprocating blades. [0041] Turning to Figures 9-11 , a reciprocating blade is illustrated and designated with the reference numeral 210. The saw blade 210 includes a body 212, a connecting portion 214 and a cutting portion 216. The cutting portion includes a plurality of teeth 224. The teeth 224 have a first tooth form 226 and a second tooth form 228. [0042] The first tooth form 226 has a rake face 232 and a relief face 234. The rake face is on a rake angle of about 0°. However, the rake angle may be between 0° to 3°. The rake face 232 has a tooth depth which is identified by the numeral 236. The relief face 234 is defined by a relief angle of between 30° to 40°, preferably, the relief angle is about 35°. The relief face is continuous with a curve portion 238 of the gullet 240. The gullet leads into a second tooth form 228. [0043] The first tooth form 226 has a desired included angle of about 50° to 55° at the tip. The tooth form 226 has an additional base area 244 which increases the mass of the tooth 226, which, in turn, increases the strength of the tooth reducing the moment and stress in the tooth base 244. The first tooth form gullet 242 has a radius defined by the numeral 246. The first tooth form 226 depth and the gullet radius 246 define the maximum gullet depth or tooth height 248. The first pitch designated with the reference numeral 250 is the distance between the tip of the second tooth form 228 and the first tooth form 226 [0044] The first tooth form depth is a length from the tip of the tooth to the curved portion of the gullet. The tooth depth has a length from about 10% to 18% of the tooth height or maximum gullet depth. Preferably, the tooth depth is about 14% of the tooth height or maximum gullet depth. [0045] The gullet radius 246 has a length between about 53% to 65% of the length of the tooth height or maximum gullet depth. Preferably, the gullet radius 246 has a length of about between 53% and 54% of the length of the tooth height or maximum gullet depth. Also, the gullet radius is between about 18% to 25% of the length of the first pitch 250. Preferably, the gullet radius 246 is about 21 % of the pitch 250. [0046] The second tooth form 228 has a rake face 262 which is on a rake angle of about 0°. However, the rake angle may be between 0° to 3°. The rake face 262 has a tooth depth identified by the numeral 266. The relief face 264 is defined by a relief angle of about 30° to 40°. Preferably, the relief angle is about 35°. The relief face 264 is continuous with the curved portion of the gullet 242. [0047] The tooth form has a desired included angle of between 50° to

55° at its tip. The included angle is preferably about 55°. Also, the tooth has an enlarged root area 268. The enlarged root area 268 increases the strength of the tooth. The increased strength reduces the moment and stress in the tooth base. [0048] The gullet 240 has a radius defined by the numeral 270. The tooth depth 266 and the gullet depth 270 define the maximum gullet length or tooth length 272. The pitch designated with the reference numeral 274 is the distance between the tip of the first tooth form and the second tooth form. [0049] The second tooth form depth 266 is a length from the tip of the tooth form 228 to the curved portion of the gullet 240. The tooth depth 266 has a length from about 15% to 25% of the tooth height or maximum gullet depth.

Preferably, the tooth depth is about 19% of the tooth height or maximum gullet depth. [0050] The gullet radius 270 has a length between about 55% to 65% of the length of the tooth height or maximum depth. Preferably, the gullet radius 270 length is about 53% of the length of the tooth height or maximum gullet length. Also, the gullet radius is between 10% to 25% the length of the pitch. Preferably, the gullet radius 270 is about 24% of the length of the pitch. [0051] The repeating first tooth form second tooth form provides an increased root between adjacent large gullets 240. Thus, both teeth are reinforced on the large root portion between the two adjacent large gullets 240. Thus, the small gullet 242 which is behind each of the large teeth would reinforce the base of that tooth when it is exposed to higher impacts. The repeating pitch which have a different size, reduces the impact on the tooth during cutting. Also, the smaller pitch enables a larger number of teeth per inch on the saw blades. Preferably, the smaller teeth size would be fourteen teeth per inch, while the larger teeth size would be ten teeth per inch. The pattern is generally raker, inside set, raker outside set, raker as seen in Figure 11. [0052] Turning to the Figures 12-16, a holesaw is illustrated and designated with the reference numeral 310. The holesaw 310 includes a cup shaped body 312, an arbor 314, and a drill bit 316. The arbor 314 as well as the drill bit 316 are like those conventionally used. The arbor 314 includes a bore to receive the drill bit 316 in a conventional way. [0053] The body member 312 includes a base 318, a cylindrical wall 320 and a cutting edge 322. The base 318 includes an arbor aperture to receive the arbor 314. The cylindrical wall 320 can have a desired diameter and is usually formed such as by stamping with the base 318. The cutting edge 322 is at the end of the wall 320 extending away from the base 318. [0054] The cutting edge 322 includes a plurality of teeth 324. The teeth 324 have a first tooth form 326 and a second tooth form 328. [0055] Turning to Figure 13, an enlarged tooth form is illustrated. The first tooth form 326 has a rake face 332 and a relief face 334. The rake face is on a rake angle of about 5° to 12°. Preferably, the rake angle is about 10°. The rake face 332 has a tooth depth which is identified by the numeral 336. The relief face 334 is defined by a relief angle of between 30° to 40°, preferably, the relief angle is about 35°. The relief face is continuous with a curve portion 338 of the gullet 340. The gullet leads into the second tooth form 328. [0056] The first tooth form 326 has a desired included angle of about 38° to 55° at the tip. The tooth form 326 has an additional base area 344 which increases the mass of the tooth 326, which, in turn, increases the strength of the tooth reducing the moment and stress in the tooth base 344. The first tooth form gullet 342 has a radius defined by the numeral 346. The first tooth form 326 depth and the gullet radius 346 define the maximum gullet depth or tooth height 348. The first pitch designated with the reference numeral 350 is the distance between the tip of the second tooth form 328 and the first tooth form 326 [0057] The first tooth form depth is a length from the tip of the tooth to the curved portion of the gullet. The tooth depth has a length from about 18% to 24% of the tooth height or maximum gullet depth. Preferably, the tooth depth is about 21% of the tooth height or maximum gullet depth. [0058] The gullet radius 346 has a length between about 53% to 65% of the length of the tooth height or maximum gullet depth. Preferably, the gullet radius 346 has a length of about between 53% and 54% of the length of the tooth height or maximum gullet depth. Also, the gullet radius is between about 18% to 25% of the length of the first pitch 350. Preferably, the gullet radius 46 is about 21% of the pitch 350. [0059] The second tooth form 328 has a rake face 362 which is on a rake angle of from about 5° to 12°. Preferably, the rake angle is about 10°. The rake face 362 has a tooth depth identified by the numeral 366. The relief face

364 is defined by a relief angle of about 30° to 40°. Preferably, the relief angle is about 35°. The relief face is continuous with the curved portion of the gullet 342. [0060] The tooth form has a desired included angle of between 38° to 55° at its tip. The included angle is preferably about 45°. Also, the tooth has an enlarged root area 368. The enlarged root area 368 increases the strength of the tooth. The increased strength reduces the moment and stress in the tooth base. [0061] The gullet 340 has a radius defined by the numeral 370. The tooth depth 366 and the gullet depth 370 define the maximum gullet length or tooth length 372. The pitch designated with the reference numeral 374 is the distance between the tip of the first tooth form and the second tooth form. [0062] The second tooth form depth 366 is a length from the tip of the tooth form 328 to the curved portion of the gullet 340. The tooth depth 366 has a length from about 30% to 40% of the tooth height or maximum gullet depth.

Preferably, the tooth depth is about 30% of the tooth height or maximum gullet depth. [0063] The gullet radius 370 has a length between about 55% to 65% of the length of the tooth height or maximum depth. Preferably, the gullet radius 370 length is about 54% of the length of the tooth height or maximum gullet length. Also, the gullet radius is between 10% to 25% the length of the pitch. Preferably, the gullet radius 370 is about 24% of the length of the pitch. [0064] The repeating first tooth form second tooth form provides an increased root between adjacent large gullets 340. Thus, both teeth are reinforced on the large root portion between the two adjacent large gullets 340. Thus, the small gullet 342 which is behind each of the large teeth would reinforce the base of that tooth when it is exposed to higher impacts. The repeating pitch which have a different size, reduces the impact on the tooth during cutting. Also, the smaller pitch enables a larger number of teeth per inch on the hole saw specifically with smaller diameters. [0065] Figures 14-16 illustrate various types of offset patterns. In Figure 14, the teeth are unset raker, inside, unset raker, outside, unset raker. In Figure 15, the pattern is offset inside, outside, inside, outside. In Figure 16, an additional pattern is shown. Here, the teeth pattern is unset raker, unset raker, inside, unset raker, unset raker, outside, unset raker, unset raker. Thus, while these provide optimal cutting, other designs could be used. [0066] The present hole saw increases the cuts per blade. Also, the present holesaw decreases the cutting time to a particular material. Also, the present holesaw reduces the wear slope of the tooth of the saw blade. This means that during use, as the teeth wear, the slope or rake face angle of the tooth form varies less than from its original slope. [0067] The described tooth forms may be used in several types of reciprocating, jig or saber saw blades. Also, the tooth forms may be used in hole saw blades. Likewise, the tooth form described in the holesaw blade may be used in reciprocating blades. [0068] The reciprocating saw blades of the present invention are preferably heat treated. The heat treating is such that the blades are heat treated for between 5-25 minutes at temperatures between 1950-2200F. This provides a desired carbide micro-structure in the saw blade. Preferably, the exposure time is 10-20 minutes at a temperature of between 2100-2150F. Ordinarily, the blades are tempered at least two or more times at a desired tempering temperature. [0069] The present reciprocating saw blade increases the cuts per blade. Also, the present saw blade decreases the cutting time through a particular metal material. Further, the present invention reduces the wear slope of the tooth of the saw blade. This means that during use, as the teeth wear, the slope or rake face angle of the tooth form varies less from its original slope than currently available reciprocating saw blades. [0070] Thus, the present design has teeth that are substantially longer than the prior art. Likewise, by having a constant rake face angle, the present invention provides a constant cutting angle over the life of the saw blade. Also, by having the desired relief angle, the saw blade of the present invention has a deeper penetration into the material it is cutting. [0071] The present design has a larger gullet area than the prior art design. The larger gullet area enables the present invention to eject chips faster from the cutting area which, in turn, enables the blade to cut faster. This combined with the longer tooth at the desired angles provides a saw blade that cuts faster and has a longer life. [0072] While the above detailed description provides the preferred embodiments of the present invention, those skilled in the art will appreciate that variation, alteration and modifications are possible without deviating from the scope and spirit of the present invention.

Claims

What is Claimed is:

1. A reciprocating saw blade tooth form comprising: a rake face having a first end forming a tip and a second end being continuous with a first gullet, a relief face extending from said tip of said rake face and continuous with a second gullet, said relief face defining a relief angle of between about 38° to about 50°, said rake face and relief face defining an included angle from about

40° to about 50°, said rake face having a desired tooth depth, said tooth depth being about 30% to about 70% of a maximum gullet depth, and about 18% to 77% of a pitch length.

2. The reciprocating saw blade according to Claim 1 wherein said first and second gullet having a radius of about 52% to about 55% of the maximum gullet depth.

3. The reciprocating saw blade according to Claim 1 wherein said rake face has an angle from about 0° to about 3°.

4. The reciprocating saw blade according to Claim 1 wherein said relief angle is between about 38° to about 42°, said included angle from about 45° to 50°, said tooth depth about 30% to about 47% of a maximum gullet and about 18% to 26% of a pitch length.

5. The reciprocating saw blade according to Claim 1 wherein said relief angle is between about 40° to about 50°, said included angle from about 40° to 50°, said tooth depth about 30% to about 70% of a maximum gullet and about 50% to 77% of a pitch length.

6. A reciprocating saw blade having a plurality of teeth, comprising: said teeth each having a tooth form including: a rake face having a first end forming a tip and a second end being continuous with a first gullet, a relief face extending from said tip of said rake face and continuous with a second gullet, said relief face defining a relief angle of between about 38° to about 50°, said rake face and relief face defining an included angle from about 40° to about 50°, said rake face having a desired tooth depth, said tooth depth being about 30% to about 70% of a maximum gullet depth, and about 18% to 77% of a pitch length.

7. The reciprocating saw blade according to Claim 6 wherein the saw blade includes set and unset teeth.

8. The reciprocating saw blade according to Claim 6 wherein said saw blade includes a raker tooth.

9. A saw blade comprising: teeth having first and second repeating tooth form; said first tooth form having a first gullet continuous with a rake face on angle from about 0° to about 12°; a relief face adjacent said rake face forming a cutting edge; said relief face at an angle of from about 30° to about 55°, and said relief face, said gullet having a desired depth such that said first tooth form has a first height; said second tooth form having a second gullet continuous with said first relief face and a second rake face, said second rake face defining a rake angle from about 0° to about 12°; and a second relief face adjacent said rake face forming a cutting edge, said second relief face on an angle of about 30° to about 55°, and said second gullet having a desired depth such that said second tooth from has a second tooth height, wherein said second tooth height is greater than said first tooth height.

10. The saw blade according to Claim 9, wherein said first and second relief angle are the same.

11. The saw blade according to Claim 9, wherein said first and second rake angles are the same.

12. The saw blade according to Claim 9, wherein said first and second tooth form cutting edges are at substantially from same height.

13. The saw blade according to Claim 9, wherein said first and second tooth form a repeating pattern.

14. The saw blade according to Claim 13, wherein said repeating first and second tooth forms may be set or unset.

15. The saw blade according to Claim 14, wherein said repeating first and second tooth forms are set left right left right.

16. The saw blade according to Claim 9, wherein said repeating first and second tooth forms are set inside, outside separated by one or more unset raker teeth.

17. The saw blade according to Claim 9, wherein said first tooth and second tooth rake face angles are between 0° to 3° and said relief angles are about 35°.

18. The saw blade according to Claim 9, wherein said first tooth and second tooth rake face angles are between 5° to 12° and said relief angles are about 35°.