Patent Publication Number: US-2022219306-A1

Title: Tool bit

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation of International Patent Application No. PCT/US2022/012536 filed on Jan. 14, 2022, which claims priority to U.S. Provisional Patent Application No. 63/137,518 filed on Jan. 14, 2021, and to U.S. Provisional Patent Application No. 63/160,080 filed on Mar. 12, 2021, the entire contents of which are incorporated by reference herein. 
    
    
     FIELD OF INVENTION 
     The present invention relates to tool bits. More particularly, the present invention relates to tool bits for use with hammer-type drills. 
     BACKGROUND 
     Rebar cutter bits are generally used with power tools such as rotary drills or hammer-type drills to cut through concrete that includes rebar. Rebar cutter bits include a cutting tip that is specifically designed to cut through rebar. Occasionally, rebar cutter bits are used with power tools that include an anvil that are operable in a rotary impact/hammer mode where the anvil strikes a bit during rotation to increase the cutting performance. However, for some rebar cutter bits, it is undesirable for the anvil to strike the bit as it may cause damage to the bit. 
     SUMMARY OF THE INVENTION 
     In one aspect, the invention provides a tool bit for use with a power tool having a chuck and an anvil. The tool bit has a first end, a second end opposite the first end, a body defining the first end of the tool bit, and a shank coupled to the body and defining the second end of the tool bit. The shank is configured to be inserted into the chuck of the power tool. The shank includes a slot formed through the second end. The slot is configured to receive a portion of the chuck to transfer rotational movement from the power tool to the tool bit. The shank also includes a ball detent spaced circumferentially from the slot. The ball detent is configured to receive a locking sphere of the chuck to lock the tool bit with the chuck. The slot is sized to limit insertion of the shank into the chuck, thereby providing a space between the second end of the tool bit and the anvil. 
     In some aspects, the space inhibits the second end of the tool from contacting the anvil during operation of the power tool. 
     In some aspects, the slot has a length. The length is between 0.2 inches and 1 inch. 
     In some aspects, the slot has a slot length and the ball detent has a ball detent length. A ratio of the ball detent length to the slot length is between 0.85 and 1.15. 
     In some aspects, the slot has a proximal slot end adjacent the second end of the tool bit and a distal slot end opposite the proximal slot end. The ball detent has a proximal ball detent end adjacent the second end of the tool bit and a distal ball detent end opposite the proximal ball detent end. The distal ball detent end is spaced generally the same distance from the first end of the tool bit as the second slot end. 
     In some aspects, the slot has a proximal slot end adjacent the second end of the tool bit and a distal slot end opposite the proximal slot end. The ball detent has a proximal ball detent end adjacent the second end of the tool bit and a distal ball detent end opposite the proximal ball detent end. The distal slot end is closer than the distal ball detent end to the second end of the tool bit. 
     In some aspects, the slot extends from the second end of the tool bit but does not extend past the ball detent in a direction parallel to an axis of rotation of the tool bit. 
     In some aspects, the slot is a first slot. The ball detent is a first ball detent. The shank further includes a second slot positioned diametrically opposite from the first slot and formed through the second end. The second slot is configured to receive another portion of the chuck to transfer rotational movement from the power tool to the tool bit. The shank further includes a second ball detent positioned diametrically opposite from the first ball detent. The second ball detent is configured to receive another locking sphere of the chuck to lock the tool bit within the chuck. 
     In some aspects, the ball detent is bounded on all sides. 
     In another aspect, the invention provides a tool bit for use with a power tool having a chuck and an anvil. The tool bit has a first end, a second end opposite the first end, a body defining the first end of the tool bit, and a shank coupled to the body and defining the second end of the tool bit. The shank is configured to be inserted into the chuck of the power tool. The shank includes a slot formed through the second end. The slot is configured to receive a portion of the chuck to transfer rotational movement from the power tool to the tool bit. The shank also includes a ball detent spaced circumferentially from the slot. The ball detent is configured to receive a locking sphere of the chuck to lock the tool bit with the chuck. The shank further includes a projection. The projection is configured to contact a surface of the chuck and limit insertion of the shank into the chuck, thereby providing a space between the second end of the tool bit and the anvil. 
     In some aspects, the space inhibits the second end of the tool from contacting the anvil during operation of the power tool. 
     In some aspects, the projection is a shoulder formed at an increased diameter portion of the shank. The shoulder extends continuously around a circumference of the shank. 
     In some aspects, the slot has a proximal end adjacent the second end of the tool bit and a distal end opposite the proximal end. The projection is adjacent the distal end of the slot. 
     In some aspects, the slot is a first slot. The ball detent is a first ball detent. The shank further includes a second slot positioned diametrically opposite from the first slot and formed through the second end. The second slot is configured to receive another portion of the chuck to transfer rotational movement from the power tool to the tool bit. The shank further includes a second ball detent positioned diametrically opposite from the first ball detent. The second ball detent is configured to receive another locking sphere of the chuck to lock the tool bit within the chuck. 
     In some aspects, the ball detent is bounded on all sides. 
     In another aspect, the invention provides a tool bit for use with a power tool having a chuck and an anvil. The tool bit has a first end, a second end opposite the first end, a body defining the first end of the tool bit, and a shank coupled to the body and defining the second end of the tool bit. The shank is configured to be inserted into the chuck of the power tool. The shank includes a first slot formed through the second end. The first slot is configured to receive a first portion of the chuck to transfer rotational movement from the power tool to the tool bit. The shank also includes a second slot positioned diametrically opposite from the first slot and formed through the second end. The second slot is configured to receive a second portion of the chuck to transfer rotational movement from the power tool to the tool bit. The shank further includes a first ball detent spaced circumferentially from the first and second slots. The first ball detent is configured to receive a first locking sphere of the chuck to lock the tool bit within the chuck. The shank also includes a second ball detent positioned diametrically opposite from the first ball detent. The second ball detent is configured to receive a second locking sphere of the chuck to lock the tool bit within the chuck. The shank is configured to limit insertion of the shank into the chuck such that the second end of the tool bit is not contacted by the anvil during operation of the power tool. 
     In some aspects, the first slot and the second slot are sized to limit insertion of the shank into the chuck. 
     In some aspects, the first slot and the second slot extend from the second end of the tool bit but do not extend past the first ball detent or the second ball detent in a direction parallel to an axis of rotation of the tool bit 
     In some aspects, the shank includes an increased diameter portion that is configured to contact a surface of the chuck to limit insertion of the shank into the chuck. 
     The above aspects may be used in any combination with each other. Other aspects of the invention will become apparent by consideration of the detailed description and accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view of a tool bit. 
         FIG. 2  is a front perspective view of the tool bit of  FIG. 1 . 
         FIG. 3  illustrates a carbide tooth of the tool bit of  FIG. 1 . 
         FIG. 4  is a perspective view of a shank of the tool bit of  FIG. 1 . 
         FIG. 5  is a first elevational view of the shank of  FIG. 4 . 
         FIG. 6  is a second elevational view of the shank of  FIG. 4 . 
         FIG. 7  is a cross-sectional view of the tool bit of  FIG. 1  coupled to a power tool. 
         FIG. 8  is a cross-sectional view of a tool bit according to another embodiment, the tool bit coupled to the power tool. 
         FIG. 9  is a first perspective view of a tool bit according to another embodiment. 
         FIG. 10  is a second perspective view of the tool bit of  FIG. 9 . 
         FIG. 11  is a front elevational view of the tool bit of  FIG. 9 . 
         FIG. 12  is a rear elevational view of the tool bit of  FIG. 9 . 
         FIG. 13  is an elevational view of a tool bit according to another embodiment. 
         FIGS. 14A-14L  illustrate a variety of different types of tool bits having modified shanks. 
         FIG. 15  is a cross-sectional view of the tool bit of  FIG. 9  taken along lines  15 - 15 . 
     
    
    
     DETAILED DESCRIPTION 
     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. 
       FIGS. 1-3  illustrate a tool bit  10 . In the illustrated embodiment, the tool bit is a cutting tool for use with a power tool  14  ( FIG. 7 ), such as, for example, a drill, a driver drill, a screwdriver, a hammer drill, a rotary hammer and the like. The tool bit  10  may be used to cut holes or drill into a workpiece made out of brick, block, tile, metal, marble, concrete, plaster, wood, plastic, dry-wall, rebar and the like. In some scenarios, the tool bit  10  may be used to cut into a workpiece that is reinforced with rebar. As such, the tool bit  10  may also be referred to as a rebar cutter bit. The illustrated tool bit  10  comes in a variety of sizes that correspond to the diameter of a hole to be created in a workpiece. For example, possible sizes of the tool bit  10  may be ⅛″, ¼″, ⅜″, and ½″. In some embodiments, the size of the tool bit  10  may be between ⅜″ and 1½″. In other embodiments, the tool bit  10  may be other sizes. 
     With reference to  FIG. 1 , the tool bit  10  includes a first or workpiece-engaging end  18 , a second or rearward end  22  configured to be received in a tool holder or chuck  24  of a power tool  14 , and an axis of rotation  26  centrally located on the tool bit  10  and extending from the first end  18  to the second end  22 . The tool bit  10  also includes a body  30  and a shank  34 . The body  30  defines the first end  18  and cuts into the workpiece. The shank  34  defines the second end  22  and is configured to be coupled to the power tool  14 . 
     The illustrated body  30  includes a helical rib  38  that defines a flute  42 . In the illustrated embodiment, the tool bit  10  includes a single rib  38  that defines a single flute  42 . In other embodiments, the tool bit  10  may include more than one rib  38  that defines multiple flutes  42 . In other embodiments, the body  30  may not include a rib  38 . The ribs  38  and flutes  42  may be helically wrapped around the body  30  at a variable helix angle. In other words, the angle at which the flutes  42  wrap about the body  30  changes as the flutes  42  extend from the first end  18  towards the second end  22 . The ribs  38  and flutes  42  facilitate chip removal from a workpiece during a cutting operation. 
     The illustrated body  30  also includes one or more apertures  46  that extend into a bore  50  of the tool bit  10 . The apertures  46  facilitate removal of material (e.g., cutting chips, slugs, etc.) from the body  30  and may also be referred to as slug removal holes. For example, a user may remove the debris or slugs from the bore  50  by extending a pick or screwdriver into one of the apertures  46 . In the illustrated embodiment, the body  30  includes two apertures  46 . In other embodiments, the body  30  may only include a single aperture  46  or may include more than two apertures  46 . In some embodiments (particularly for smaller diameter tool bits), the apertures  46  and the bore  50  may be omitted. 
     With reference to  FIG. 2 , the body  30  includes a cutting head  54  adjacent the first end  18  of the tool bit  10 . The cutting head  54  includes an annular rim  58  that defines an opening  62  that extends into the bore  50  of the tool bit  10 . The opening  62  is configured to receive debris (e.g., slugs) during a cutting operation. For example, the opening  62  may receive cutting chips and other material that form into slugs in the bore  50  while cutting into a workpiece. As mentioned above, in some embodiments, the bore  50  may be omitted from the tool bit  10 . 
     With continued reference to  FIG. 2 , the illustrated cutting head  54  includes a plurality of slots  66  that each receive a cutting tooth  70 . In the illustrated embodiment, the cutting head  54  includes six slots  66  to receive six cutting teeth  70 . In other embodiments, the cutting head  54  may include more than or less than six slots  66  to receive a corresponding number of cutting teeth  70 . As shown, in  FIG. 3 , each cutting tooth  70  defines a cutting edge  74  that extends further from the first end  18  of the body  30  than the annular rim  58  to contact a workpiece. The cutting edge  74  defines a plurality of relief surfaces  78 . In some embodiments, the relief surfaces  78  may vary per cutting tooth  70  to provide a different cutting pattern. For example, every other cutting tooth  70  may include four relief surfaces  78  while every adjacent cutting tooth  70  includes three relief surfaces  78 . In the illustrated embodiment, the cutting edge  74  of each tooth is aligned on a leading edge each of the slots  66 . In some embodiments, the cutting teeth  70  are made of carbide. In further embodiments, the cutting teeth  70  may be coupled to the body  30  by brazing or welding. In further embodiments, a single carbide cutting portion may be coupled to the cutting head. The carbide cutting portion would include a plurality of cutting teeth. The cutting teeth may be integral with the carbide cutting portion. For example, the cutting teeth may be carved, grounded, or cut into the carbide cutting head. Further, the carbide cutting portion may be coupled to the cutting head by welding, brazing or other methods. 
       FIG. 4-6  illustrate the shank  34  of the tool bit  10 . In some embodiments, the shank  34  may be formed integral with the body  30 . In other embodiments, the shank  34  may be secured to the body  30  by brazing, welding, or other methods. In the illustrated embodiment, the shank  34  is a modified SDS shank. The shank  34  includes a main portion  82  having a first end  86  adjacent the body  30  and a second end  90  opposite the first end  86 . The first end  86  of the main portion  82  provides a blank surface that may include laser etching indicating to the user the size of the tool bit  10  or other information. The second end  90  of the shank  34  includes a pair of ball detents  94  and a pair of slots  98  (although only one ball detent  94  and one slot  98  is shown in  FIGS. 4-6 ). The ball detents  94  are on diametrically opposite sides of the axis of rotation  26  from one another. Similarly, the slots  98  are on diametrically opposite sides of the axis of rotation  26  from one another other. In some embodiments, the tool bit  10  may only include a single ball detent  94  and/or a single slot  98 , or the tool bit  10  may include more than two ball detents  94  and/or slots  98 . Each illustrated ball detent  94  is positioned 90 degrees circumferentially from an adjacent slot  98  and vice versa. The ball detents  94  further include an indent  102  that is further recessed into the shank  34  in a direction radially toward the axis of rotation  26  than the ball detent  94 . 
     In the illustrated embodiment, a length L 1  of each ball detent  94  is similar to a length L 2  of each slot  98 . In other words, a ratio of the length L 1  of the ball detents  94  to the length L 2  of the slots  98  is a range between 0.85 and 1.15. Further, the ball detents  94  and the slots  98  only extend along a portion of the shank  34 . Specifically, in the illustrated embodiment, the length L 1  of the ball detents  94  and the length L 2  of the slots  98  extend between one-fifth and one-third a total length of the shank  34 . As such, the slots  98  and detents  94  are shortened compared to other or standard SDS shanks. In further embodiments, if the length of the shank  34  were increased, the length L 1  of the ball detents  94  and the length L 2  of the slots  94  would remain constant. In such an embodiment, the length L 1  of the ball detents  94  and the length L 2  of the slots  94  may be between 0.2 inches and 1 inch. 
     The illustrated slots  98  do not extend past the ball detents  94  in a direction parallel to the axis of rotation  26  ( FIG. 1 ). Each slot  98  is formed through the second end  90  of the shank  34  and extends toward the first end  86 . Each slot  98  has a proximal end  98   a  at the second end  90  and a distal end  98   b  opposite the proximal end  98   a . Each ball detent  94 , in contrast, does not extend through the second end  90  such that the ball detents  94  are bounded on all sides. Each ball detent  94  has a proximal end  94   a  adjacent the second end  90  and a distal end  94   b  opposite the proximal end  94   a . In conventional SDS shanks, the slots  98  typically extend a further distance along the shank  34  and past the ball detents  94 . That is, the distal ends  98   b  of the slots  98  are typically closer than the distal ends  94   b  of the ball detents  94  to the first end  86  of the shank  34 . Stated another way, in conventional SDS shanks, the distal ends  98   b  of the slots  98  are spaced further than the distal ends  94   b  of the ball detents  94  from the second end  90  of the shank  34 . In the illustrated embodiment, the distal ends  98   b  of the slots  98  are spaced generally the same distance from the first and second ends  86 ,  90  of the shank  34  as the distal ends  94   b  of the ball detents  94 . In some embodiments, the distal ends  98   b  of the slots  98  may be spaced further than the distal ends  94   b  of the ball detents  94  from the first end  86  of the shank  34 . In such embodiments, the distal ends  98   b  of the slots  98  may be closer than the distal ends  94   b  of the ball detents  94  to the second end  90  of the shank  34 . 
       FIG. 7  illustrates the tool bit  10  coupled to the power tool  14 . The power tool  14  includes the chuck  24  to receive the tool bit  10  and an anvil  106 . The anvil  106  is configured to impart an impact force on a tool bit received within the chuck  24 . To operate the tool bit  10 , the second end  22  of the tool bit  10  (e.g., the shank  34 ) is inserted into the chuck  24  of the power tool  14 . Pins or keys of the power tool  14  are received in the slots  98  to transfer rotational movement to the tool bit  10  and locking spheres  108  (schematically illustrated) are received in the indents  102  of the ball detents  94  to lock the tool bit  10  within the chuck  24 . The pins or keys and the locking spheres  108  are movable axially within the ball detents  94  and the slots  98 , respectively, to reduce the fatigue on the shank  34 . Additionally, as mentioned above, the shortened lengths of the ball detents  94  and the slots  98  prevent the shank  34  from fully inserting into the chuck  24 , providing a space  110  between the tool bit  10  and the anvil  106 . As such, during a cutting operation, the anvil  106  does not contact the second end  90  of the shank  34  to impart an impact force on the tool bit  10 . In other words, the space  110  inhibits the second end  22  of the tool bit  10  from contacting the anvil  106  during operation of the power tool  14 . 
     In other embodiments, the shank  34  may be made from a different material than the body  30 . For example, the end of the shank  34  may be made of a softer material than the material used for the body  30 . In such an embodiment, the end of the shank  34  would be operable to absorb an impact from the anvil  106  without harming the integrity of the tool bit  10 . In further embodiments, the shank  34  may be spring loaded to absorb the impact energy from the anvil  106 . In such an embodiment, the shank  34  may include a resilient member that biases the shank  34  away from the body. Then, if the shank  34  were to receive an impact force from the anvil  106 , the shank  34  would move against the bias of the resilient member to absorb the impact energy from the anvil  106  preventing harm to the tool bit  10 . 
     Providing a tool bit  10  with a modified SDS shank  34  that includes slots  98  inhibits the tool bit  10  from being impacted by an anvil  106  of a power tool  14  when received in the chuck  24  of the power tool  14 , which may extend the life of the tool bit  10 . 
       FIG. 8  illustrates a tool bit  210  according to another embodiment of the invention. The tool bit  210  is similar to the tool bit  10 , but includes a different shank  214 . The illustrated shank  214  includes a first end  218  and a second end  222  opposite the first end  218 . The first end  218  includes a pair of elongated slots  226  and a pair of ball detents  230 . In the illustrated embodiments, the slots  226  and the ball detents  230  are typical of a conventional SDS design. Locking spheres  108  are received in the ball detents  230  to lock the tool bit  10  within the chuck  24 . The shank  214  also includes a projection. The projection is positioned adjacent distal ends of the sots  226 . In the illustrated embodiment, the projection is a shoulder  234  formed at an increased diameter portion of the shank  214 . The shoulder  234  extends continuously around a circumference of the shank  214 . As such, the shoulder  234  is integrally formed with the shank  214 . When inserted into the chuck  24  of the power tool  14 , the shoulder  234  abuts a forward surface  238  of the chuck  24 , preventing the shank  214  from fully inserting into the chuck  24 . A space  242  is left between the shank  214  and the anvil  106  so that the anvil  106  cannot contact the second end of the shank  214  to impart an impact force on the tool bit  210  during a cutting operation. In other embodiments, the projection may have other configurations. For example, the projection may be a separate piece that is secured (e.g., brazed or welded) to the shank  214 . Alternatively, the projection may be a single, discrete projection on the shank  214  or may be a series of discrete projections. 
     In some embodiments, shank  34  of the tool bit  10  or the shank  214  of the tool bit  210  may be SDS max designs. Providing a tool bit  10 ,  210  with a modified shank that inhibit impact from an anvil  106  allows for heavier rebar cutters that include an SDS max design. For example,  FIGS. 9-12  illustrate a tool bit  310  according to another embodiment of the invention. The tool bit  310  is similar to the tool bits  10 ,  210  but includes a modified SDS max shank according to another embodiment. 
     In the illustrated embodiment, the tool bit  310  includes a first or workpiece engaging end  314  and a second or rearward end  318  configured to be received in a tool holder or a chuck of a power tool. The tool bit  310  also includes a body  322  extending between the first and second ends  314 ,  318  and a shank  326  that defines the second end  318 . In the illustrated embodiment, the shank  326  is a modified SDS max shank. In comparison, the shank  34  of the tool bit  10  shown in  FIG. 1  may be referred to as a modified SDS plus shank. Generally, SDS max shanks include a greater diameter than SDS plus shanks. For example, the shank  326  may include a max diameter D 1  between ½″ and 1¾″, whereas SDS plus shanks may include a diameter between 5/32″ and 1¼″. Specifically, the shank  326  may have a max diameter that is 18 millimeters or 0.71 inches. Additionally, as will be described in more detail below, SDS max shanks include at least one wider slot with a projection that separates the slot into two distinct smaller slots ( FIG. 15 ). As shown in  FIGS. 11 and 12 , a max diameter D 1  of the shank is generally equal to a max diameter D 2  of the body  322  or the tool bit  310 . Including a similar diameter between the body  322  and the shank  326  allows the tool bit  310  to withstand higher torques when engaging a workpiece. 
       FIGS. 11 and 12  illustrate the shank  326  of the tool bit  310 . The shank  326  may be described as a non-working end of the accessory that is inserted into the chuck  24  of the power tool  14  to transmit motion to the workpiece engaging end  314 . The length of the shank  326  serves as a portion of the tool bit  310  to distance the body  322  and the workpiece engaging end  314  from the chuck  24 . In some embodiments, the shank  326  may be formed integral with the body  322 . In other embodiments, the shank  326  may be secured to the body  322  by brazing, welding, or other methods. The shank  326  includes a pair of ball detents  330 , a first slot  334   a , and a second slots  334   b  ( FIG. 10 ). The ball detents  330  are on diametrically opposite sides of an axis of rotation  338  from one another. Similarly, the slots  334   a ,  334   b  are on diametrically opposite sides of the axis of rotation  338  from one another other. Each illustrated ball detent  330  is positioned 90 degrees circumferentially from an adjacent slot  334   a ,  334   b  and vice versa. As shown in  FIG. 15 , the first slot  334   a  includes a similar cross-sectional profile as the slots  98  described above. The second slot  334   b  includes a projection  336  that defines two smaller slots  337   a ,  337   b . The two smaller slots  337   a ,  337   b  provide more surface area for the chuck of a rotary power tool to engage the tool bit  310  allowing better transfer of torque from the power tool to the tool bit that may be needed for the wider dimensions of an SDS max shank. 
     In the illustrated embodiment, a length L 3  of each ball detent  330  is similar to a length L 4  of each slot  334   a ,  334   b . In other words, a ratio of the length L 3  of the ball detents  330  to the length L 4  of the slots  334   a ,  334   b  is in a range between 0.85 and 1.15. Further, the ball detents  330  and the slots  334   a ,  334   b  only extend along a portion of the shank  326 . Specifically, in the illustrated embodiment, the length L 3  of the ball detents  330  and the length L 4  of the slots  334   a ,  334   b  extend between one-tenth and seven-tenths a total length of the shank  34 . In addition, the length L 3  of the ball detents  330  and the length L 4  of the slots  334   a ,  334   b  extend long enough to engage the chuck  24  of the power tool  14  to transfer rotation, but short enough to not receive impact from the anvil  106 . As such, the slots  334   a ,  334   b  and detents  330  are shortened compared to other or standard SDS max shanks. In further embodiments, if the length of the shank  326  were increased, the length L 3  of the ball detents  330  and the length L 4  of the slots  334   a ,  334   b  would remain constant. In such an embodiment, the length L 3  of the ball detents  330  and the length L 4  of the slots  334   a ,  334   b  may be between 0.2 inches and 2 inches. 
     The illustrated slots  334   a ,  334   b  extend slightly past the ball detents  330  in a direction parallel to the longitudinal axis  338 . Each slot  334   a ,  334   b  is formed through the second end  318  of the tool bit  310  and extends toward the first end  314 . Each slot  334   a ,  334   b  has a proximal end  335   a  at the second end  318  and a distal end  335   b  opposite the proximal end  335   a . The distal end  335   b  defines an inclined surface  342  that extends to the outer periphery of the shank  326 . Each ball detent  330 , in contrast, does not extend through the second end  318  such that the ball detents  330  are bounded on all sides. Each ball detent  330  has a proximal end  330   a  adjacent the second end  318  and a distal end  330   b  opposite the proximal end  330   a . In conventional SDS shanks, the slots  334   a ,  334   b  typically extend a further distance along the shank  326  and past the ball detents  330 . That is, the distal ends  335   b  of the slots  334   a ,  334   b  are typically closer than the distal ends  330   b  of the ball detents  330  to the first end  314  of the tool bit  310 . Stated another way, in conventional SDS shanks, the distal ends  335   b  of the slots  334   a ,  334   b  are spaced further than the distal ends  330   b  of the ball detents  94  from the second end  318 . In the illustrated embodiment, the distal ends  335   b  of the slots  334   a ,  334   b  are spaced generally the same distance from the first and second ends  314 ,  318  as the distal ends  330   b  of the ball detents  330 . In some embodiments, the distal ends  335   b  of the slots  334   a ,  334   b  may be spaced further than the distal ends  330   b  of the ball detents  330  from the first end  314 . In such embodiments, the distal ends  335   b  of the slots  334   a ,  334   b  may be closer than the distal ends  330   b  of the ball detents  330  to the second end  318 . 
     The tool bit  310  is configured to be inserted into a chuck of a power tool that receives SDS max shanks. Generally, rotary power tools configured to receive SDS max tool bits are operable in two modes: a hammer only mode, in which an anvil provides only a percussive force to the end of a tool bit, and a rotary hammer mode, in which the anvil provides a percussive force to a tool bit while the tool bit is rotated. Similar to the tool bit  10 , the shortened lengths of the ball detents  330  and the slots  334   a ,  334   b  prevent the shank  326  from fully inserting into the chuck of a SDS max rotary power tool. As such, during a cutting operation, an anvil  106  does not contact the shank  326  to impart an impact force on the tool bit  10 . 
       FIG. 13  illustrates a tool bit  410  including a shank  428  having a tool engagement portion  432  and a reduced diameter portion  436 . The reduced diameter portion  436  may be included on the shanks  34 ,  214 ,  326  of the tool bits  10 ,  210 ,  310  discussed above. The reduced diameter portion  436  removes localized regions of high stress and discontinuities, thereby increasing the durability of the shank  428  to extend the operational lifetime of the tool bit  410 . In some embodiments, the reduced diameter portion  436  may be disposed between the shank  428  and a body  424  of the tool bit  410 . The reduced diameter portion  436  may provide a transition from the shank  428  to the rest of the body  424 . In further embodiments, the reduced diameter portion  436  may be between 70%-99% of the diameter of the shank  428 . For example, when the reduced diameter portion  436  is included on the shank  326  of the tool bit  310 , the reduced diameter portion  436  may be between 70%-99% of the diameter D 1  of the shank  326 . The reduced diameter portion  436  may be similar to the reduced diameter section discussed in U.S. Pat. No. 10,421,130, the entire contents of which are hereby incorporated by reference. 
     In some embodiments, the tool bits  10 ,  210 ,  310 ,  410  may be coated with a rust preventive coating that is applied to the entire tool bit  10 ,  210 ,  310 ,  410 . In further embodiments, the tool bits  10 ,  210 ,  310 ,  410  may be coated with a PVD (physical vapor deposition) coating, such as titanium-nitride coating or with black oxide. 
     In further embodiments, the shank  34  of the drill bit  10 , the shank  214  of the drill bit  210 , or the shank  326  of the drill bit  310  may be used with a number of different tool bits.  FIGS. 14A-14L  disclose tool bits that may include one of the shanks  34 ,  214 ,  326  discussed above. For example, the shanks  34 ,  214 ,  326  may be used with a glass and tile bit  500  ( FIG. 14A ), a natural stone bit  600  ( FIG. 14B ), a driver bit  700  ( FIG. 14C ), a socket adapter  800  ( FIG. 14D ), a hole saw assembly including a shank  900  ( FIG. 14E ), a self-feed bit  1000  ( FIG. 14F ), a chuck adapter  1100  ( FIG. 14G ), a core drilling bit  1200  ( FIG. 14H ), a spade drill bit  1300  ( FIG. 14I ), a wood auger  1400  ( FIG. 14J ), an anchor setting kit assembly  1500  ( FIG. 14K ), or a metal/concrete bit  1600  ( FIG. 14L ). 
     Although the invention has been described in detail with reference to certain embodiments above, variations and modifications exist within the scope and spirit of the invention. Various features and advantages of the invention are set forth in the following claims.