Abstract: The present invention provides a novel drill insert having chipbreakers, or chip splitting grooves formed through the cutting surfaces. The cutting tool insert has a specialized geometry including a chip splitting groove formed at a negative rake angle. The chip splitting grooves increase the cutting efficiency of the tool while allowing the edge strength to be increased while also allowing higher feed rates.

Abstract: A twist drill is made of a carbide alloy and has a pair of helical flutes. The flutes are defined by heel surfaces. Each heel surface bulges, or is formed arcuate, and contacts a margin. The center of the arc is located in the drill. The radius of curvature of each heel surface is from one sixth to one third of the diameter of a drill portion. Stress that acts on heels due to forming holes is dispersed by the arcuate shape. This improves the rigidity of the twist drill. Also, swarf is reliably cleared and is not stuck in the flutes. This improves the smoothness of the surface of the formed hole.

Abstract: A throwaway tip comprises a base which is to be held between a pair of holder pieces of a holder. A cutting edge is provided on a front edge of the base. A pair of holder bearing faces to be respectively brought into abutment against the holder pieces are respectively provided on sides of the base. A rear bearing face to be brought into abutment against a bottom of a pocket of the holder is provided on a rear side of the base. The rear bearing face is substantially orthogonal to the holder bearing faces. Most of a thrust load exerted on the tip during a drilling operation is stably received by the bottom of the pocket.

Abstract: A self-centering drill comprising: (a) a shank, a body, and a cutting end, all formed integrally in the drill; (b) the body interposed between the shank and the cutting end, the body having a pair of helical flutes and a corresponding pair of helical lands; (c) the cutting end including a substantially flat bottom section having primary cutting lips which are relief ground, the primary cutting lips forming a primary point angle, and a helical crown having a helical crown point tip that extends from the bottom section, the helical crown point tip having self-centering cutting lips; (d) wherein the outside edges of the bottom section are chamfered to form secondary cutting lips which are radially relieved, the secondary cutting lips forming a secondary point angle, (e) the primary point angle being greater than the secondary point angle.

Abstract: An improved rotary cutting tool overcomes the disadvantages and limitations of known constructions through the use of least one primary flute defining a low-angle cutting surface, and at least one secondary flute defining a high-angle cutting surface. The primary and secondary flutes intersect to form a compound cutting surface having a continuous cutting edge including a leading cutting edge formed along at least a portion of the low-angle cutting surface, and a trailing cutting edge formed along at least a portion of the high-angle cutting surface. The invention may further include a cooling channel and at least one aperture exiting out of the main body portion to provide a cooling fluid to one of more of the cutting edges. In a different embodiment, the leading cutting edge begins from a leading point and the trailing edge terminates in a trailing point, and one or both of the leading and trailing points are eased to reduce scoring.

Abstract: On a drill with a base body and a replaceable cutting insert, the cutting insert lies in a receptacle that runs through the base body at a right angle to the latter's longitudinal axis and is open toward the drill tip, whereby the cutting insert is in contact by means of two diametrically opposite contact surfaces against the side walls of the receptacle. Between each contact surface of the cutting insert and a side wall of the receptacle, there is a groove that extends in the direction of the longitudinal axis, in which groove a clamping wedge sits with a form-fit and a friction-fit, and interacts with the base body and the cutting insert in the manner of a self-locking device that acts toward the drill tip.

Abstract: A method for reaming a hole in a metal substrate that minimizes the tendency of long and stringy metal chips to be formed that can surround the reamer with a “steel wool-like” mesh or mass of material, as well as an improved reamer for carrying out this method. The reaming method involves longitudinally advancing the chamfered end of the reamer into the hole at an increased rate of at least about 5 mils (0.13 mm) per cutting edge as the hole is reamed during rotation of the reamer. For holes or bores having a length (L) that is at least about 3 times the cutting diameter (D) of the reamer, a preferred subsequent step is to momentarily reduce the rate of advance of the chamfered end into the hole to about 1 mil (0.025 mm) or less per cutting edge for from about 1 to about 5 rotations of the reamer.

Abstract: The rotary cutting tool of the present invention employs roughing and finishing blades on the same tool to produce roughing and finishing cuts in one cutting operation. The rotary cutting tool preferably has a roughing flute adjacent to each roughing blade and a finishing flute adjacent to each finishing blade. In highly preferred embodiments, the finishing flutes are smaller than the roughing flutes. Preferably, each finishing flute is located closer to the preceding roughing flute (with reference to tool rotational direction) than to the following roughing flute. The flutes are therefore preferably unequally spaced. In some highly preferred embodiments, the blades are unequally circumferentially spaced and are immediately behind the flutes. At least one finishing blade preferably extends radially farther than at least one roughing blade. Most preferably, all of the finishing blades extend radially farther than all of the roughing blades.

Abstract: A reaming tool for reaming bone canals with a drill head which is mounted on an elongate flexible shaft which has a diameter smaller than that of the drill head and be which can be connected to a rotary drive motor, wherein the drill head and shank comprise a through-bore for a guiding wire wherein the shaft at least over a part of its length is spiraled in a thread-like manner.

Abstract: A twist drill bit has first and second inclined cutting teeth. The first inclined cutting tooth includes at a first cutting edge a first guide projection formed at the periphery of the drill bit, and the second inclined cutting tooth includes at a second cutting edge a second guide projection formed at the periphery of the drill bit. The first and second guide projections have respective first and second guide faces that contact the work piece as the drill bit removes material from it.

Abstract: The present invention relates to a throwaway tip of single tip type having an inner cutting edge for cutting a center area of a hole being drilled and an outer cutting edge for cutting a circumference area of the hole, and to a drill holder for holding the throwaway tip. The tip is characterized in that a step gap between a first rake face and a second bearing face on the side of the inner cutting edge are spanned by a first curved surface, and the drill holder is characterized in that a connection surface thereof adjacent to the first rake face is inclined in the same direction as an inclination of the helix of a flute, whereby chip ejection is facilitated.

Abstract: A tool such as a drill or end mill has a central portion formed of a relatively tough hard material connected to an outer peripheral portion formed of relatively wear resistant hard material, i.e., the outer peripheral portion is more brittle and wear resistant than the central portion. The chip flutes of the tool are disposed only in the outer peripheral portion and thus are formed entirely of relatively wear resistant hard material.

Abstract: A deburring tool for performing non-abrasive deburring of metal and other hard-material parts subject to burring. The deburring tool comprises a portion shaped to engage a specific surface on a workpiece, and surfaced with a deburring material comprising the soft, fuzzy, female loop half of ordinary hook and loop fastener. The female loop half of the hook and loop fastening material is non-abrasive, yet is extremely effective at removing small burrs and shavings from metal parts. In a preferred form, the deburring tool forms a two-sided deburring channel or track through which a part such as a hose connector block having a recessed surface needing deburring can be swiped. Both sides of the channel are surfaced with the female loop half of the hook and loop fastener as the deburring medium.

Abstract: A rotatable cutting tool includes a rotatable tool body and a replaceable cutting tip for chip removing machining. The tool body includes a forward free end having a first dovetail coupling part formed thereon. The cutting tip includes a front cutting end and a rear mounting end. The mounting end includes a second dovetail coupling part joined to the first dovetail coupling part. An actuator, such as a screw, is provided which is arranged for elastically deforming one of the dovetail coupling parts to create a tightly clamped relationship between the first and second dovetail coupling parts. Insertion of a replacement cutting tip is performed by laterally mating the dovetail coupling parts until one of the coupling parts abuts a laterally facing stop surface of the other coupling part.

Abstract: A cutting tool (500) has a longitudinally extending shaft portion (588) with a chucking part (509) and a cutting head (506). A pressed powder cutting insert (518) with a cutting edge (520) is on the cutting head (506). The cutting edge (520) includes at least one cutting portion. A rake surface (524) is formed adjacent to at least one of the cutting portions (520) with the rake face (524) being at a rake angle from about 0° to 10°. A clearance face (526) is formed adjacent to the at least one cutting portion opposite the rake face (524). The clearance face (526) is at a clearance angle from about 10° to 50°. An edge radius (540) between the rake face (524) and the clearance face (526) is at a radius of from about 0.0015 to about 0.004 inch. The edge radius 540 is formed during pressing of the powder to form the insert, thus, enabling the insert to be directly braised into the cutting head (506).

Abstract: A hole forming tool has a main body constructed of a cemented carbide comprising 10±2 wt % Co. 0.65±0.25 wt % Cr, WC for the balance, and inevitable impurities. The average particle diameter of WC is in the range of 0.1 to 1.0 &mgr;m, and a radial rake angle of cutting edges formed at the end of the hole forming tool is set to a negative value in the range of −5° to −10°. Chip discharging grooves of which the helix angle is in the range of 5° to 15° are formed in the exterior surface of the hole forming tool. A groove width ratio of land portions and the chip discharging grooves is in the range of 0.9 to 1.1. A point angle is in the range of 125° to 1.35°, and a core diameter is in the range of 0.38D to 0.42D, in which D is the outside diameter of the drill. The main body of the hole forming tool is coated with a TiAlN layer.

Abstract: A tool for chip removing machining includes a drill and a countersinker mounted thereto. The countersinker comprises two half-sections that are clamped to each other and to the drill. The drill includes helical flutes defining respective chip-removal channels. Each half-section includes a connection portion received in a respective flute of the drill. The connection portion has a shape generally corresponding to that of the chip flute, so as to be form-locked within the flute. Each connection portion includes a convex surface facing the flute, and a concave surface facing away from the convex portion. The convex surface can be pressed against the concave wall of the flute, whereby the concave surface forms a section of a wall of a respective chip-removal channel.

Abstract: A cutting tool (200, 202) has a longitudinally extending shaft portion (208) with a chucking part (204) and a cutting head (206). A cutting edge (220) is formed on the cutting head (206). The cutting edge (220) includes at least one cutting portion. A rake surface (224) is formed adjacent to at least one of the cutting portions (220) with the rake face being at a rake angle in the range from about −10° to about 10°. A clearance face (226) is formed adjacent to the at least one cutting portion opposite the rake face (224). The clearance face (226) is at a clearance angle in the range from about 10° to about 50°. An edge radius between the rake face and the clearance face is at a radius of from about 0.0003 to about 0.0040 inch.

Abstract: A masonry drill bit 1 having an active diameter of D, comprising a shaft 3 and a tip 5 for engaging a workpiece, the tip 5 including a central portion 11 extending ahead of an outer portion 13, wherein the central portion 11 has a width of at least 0.25D and is shaped to act as a chisel during percussion drilling, and wherein the outer portion 13 is shaped to cut a workpiece as the drill bit rotates. By virtue of the drill bit tip 5 configuration as described and claimed herein, a masonry drill bit 1 having improved performance is provided.

Abstract: An improved twist drill is provided which reduces wear or chippings of the major cutting edges (3) and those of the leading edges (7) of land (9) and which has a long service life and stays sharp. A twist drill has a pair of chip discharge flutes (6), a pair of chisel edges (1), a pair of inner cutting edges (2) and a pair of major cutting edges (3) extending from each outer end of the inner cutting edges (2). Further, the drill has a pair of outer cutting edges (4) each receding from each of the major cutting edges (3) at an angle (&agr;1), and a pair of leading edges (7) of lands (9) each formed by the land (9) and the outer cutting edge (4) and has a linear or curved rake face (8). Wherein, an angle (&agr;4) of the leading edge (7) of land (9) between the leading edge (7) of the land (9) between the leading edge (7) of the land (9) and the linear or curved rake face (8) is an obtuse angle.

Abstract: A bone drill extending along an axis has (1) a stabilizing point with first and second cutting edges which extend to a tip, conical wall sections and flutes on opposite sides of each of the first and second cutting edges and (2) first and second lands extending radially outwardly from the conical wall sections, each land having a radially outwardly extending cutting edge.

Abstract: A drill used for dry drilling, characterized by the asymmetry of those cutting edge parts only whose faces are in the drill core area, in particular its entire chisel edge. This asymmetry can result from the fact that the individual chisel edges have different lengths.

Abstract: The invention relates to an indexable drill for drilling a hole in a metal workpiece. The drill includes an elongated generally cylindrical body having a central longitudinal axis and a pair of cutting inserts. The body includes a tip end portion having first and second recessed pockets on generally diametrically opposite sides of the longitudinal axis. Each cutting insert is removably secured within a pocket and includes at least one cutting edge having an outer peripheral corner and an inner corner. The at least one cutting edge extends linearly from the outer peripheral corner to a curve extending convexly toward an inner region proximate the central longitudinal axis and then to a linear relief edge extending linearly from the inner region in a direction away from the longitudinal axis to the inner corner.

Abstract: A drilling tool includes a shaft having a front end to which a cutting body provided with cutting edges is detachably connected. In the front end of the shaft, a seat is formed which is delimited by spaced-apart protrusions between which there is a bottom surface. In the protrusion, there is a threaded hole for a screw, which when tightened applies pre-stressing forces to the cutting body. On the inside of the opposite protrusion, there is a supporting shoulder against which the cutting body is pressed when the screw is tightened and applies a lateral pre-stressing force to the cutting body. The protrusions are laterally displaced in relation to each other in order to freely expose the screw beside one of the protrusions.

Abstract: The present invention relates to a throwaway tip of single tip type having an inner cutting edge for cutting a center area of a hole being drilled and an outer cutting edge for cutting a circumference area of the hole, and to a drill holder for holding the throwaway tip. The tip is characterized in that a step gap between a first rake face and a second bearing face on the side of the inner cutting edge are spanned by a first curved surface, and the drill holder is characterized in that a connection surface thereof adjacent to the first rake face is inclined in the same direction as an inclination of the helix of a flute, whereby chip ejection is facilitated.

Abstract: A throwaway tip comprises a base which is to be held between a pair of holder pieces of a holder. A cutting edge is provided on a front edge of the base. A pair of holder bearing faces to be respectively brought into abutment against the holder pieces are respectively provided on sides of the base. A rear bearing face to be brought into abutment against a bottom of a pocket of the holder is provided on a rear side of the base. The rear bearing face is substantially orthogonal to the holder bearing faces. Most of a thrust load exerted on the tip during a drilling operation is stably received by the bottom of the pocket.

Abstract: A helically fluted twist drill device is disclosed for cutting materials. The device includes a cylindrical core having a first diameter, a longitudinal axis and a first and a second extremity, the second extremity defining a cutting point. At least three portions extend helically outwardly away from the core so that the portions define a second diameter. The arrangement is such that adjacent portions define therebetween a helical flute. Each of the flutes has a flute surface which is of S-shaped configuration when viewed as a cross section disposed normal to the longitudinal axis, the cross section being viewed in a direction from the first towards the second extremity. Each of the portions further defines a helical bore connected to a source of a cutting fluid for permitting a flow of the cutting fluid through the bore towards the cutting point. The arrangement is such that in use of the device, the cutting fluid conveys the materials away from the cutting point through each flute.

Abstract: A tool tip and tool body assembly includes a tool tip having a first end for contacting a workpiece and a second end, the second end having a patterned surface of recesses and protrusions, and at least one through hole extending through the tool tip from the second end. A tool body has a first end having a patterned surface corresponding to the patterned surface of the tool tip for mating with the patterned surface of the tool tip, and at least one threaded hole adapted to align with the at least one through hole in the tool tip. At least one fastener having a threaded end and a securing end is provided, the fastener extending through the at least one through hole such that the securing end abuts against a surface in the at least one through hole, the threaded end mating with threads in the threaded hole. Torque is transmitted between the tool tip and the tool body solely by the at least one fastener and the patterned surface of the tool tip and the patterned surface of the tool body.

Abstract: The invention is directed to an improved cutting tool point. In the preferred embodiment, the cutting tool is comprised of a marginal end portion (15), adapted to selectively remove material from a work piece when the tool is moved relative to the work piece and having a leading cutting lip (16), a trailing dam (18), a recessed surface (19) extending into the marginal end portion between the cutting lip and the dam, and a coolant hole (20) communicating with the recessed surface, such that the recessed surface forms a reservoir (40) for coolant (36). The present invention also discloses a marginal end portion having an axis of rotation (42), at least one flute (21), and at least one chip-forming notch (31) extending from the flute into the marginal end portion and beyond the axis of rotation. The present invention also discloses a marginal end portion having a chip former (37) and a chip breaker (32).

Abstract: A drill bit for drilling a bore is disclosed. The drill bit includes a body having a shank portion, a tip portion and an axis of rotation therethrough. The tip portion has a plurality of touching points, wherein all of the plurality of touching points form a plurality of cutting edges that are aligned along the entire length of a common diameter line. Alternately, the plurality of cutting edges may be aligned along the entire length of a diameter of the drill bit on different diameter lines.

Abstract: A boring bit, especially a multi-blade boring bit. The bit preferably has a point symmetric cutting edge arrangement having main and secondary cutting edges that are tilted towards the axis of the boring bit. In order to stabilize the tool against vibrations cased by the cutting force, the secondary cutting edge is tilted along an effective length that is substantially axial in the direction of cutting thereby having a negative tool side rake.

Abstract: A drill having a drill head with a drill shank extending between the drill head and a plug-in end lying opposite the drill head, said drill shank having a conveying helix formed by at least two helical flutes and webs located between the flutes. The flutes comprise the same clear cross section at least in the region of the end of the drill shank adjacent the drill head and are arranged at an angle a in a range of 130° through 170° relative to one another.

Abstract: A drilling tool including a substantially columnar tool body rotatable about an axis, the tool body having a chip discharge groove formed in the outer periphery thereof opened at a distal end surface of the tool body; and a cutting edge having a rake face and extending from an end adjacent to the axis toward the outer periphery of the tool provided along a crossing ridge between a wall surface of the chip discharge groove facing in a circumferential direction of the tool and the distal end face. In the drilling tool, a concave surface rises in the circumferential direction of the tool with respect to the rake face of the cutting edge, the concave surface forming a concave curve advancing toward the distal end face of the tool in the circumferential direction of the tool, the concave surface being formed between the crossing ridge and the distal end face.

Abstract: A rotary cutting tool is disclosed having an evacuation bore in a shank and generally radially extending passages opening to the bore to conduct away material being removed by cutters. Intersecting cutters are disposed at the intersections of right and left-hand flutes in the tool shank. The right-hand flutes extend along the entire length of the tool shank. The left-hand flutes extend from one end of the shank to an opposite end spaced from the lead end of the shank to leave only the end portion of the right-hand flutes extending to a lead end of the tool shank.

Abstract: A cutting tool (200, 202) has a longitudinally extending shaft portion (208) with a chucking part (204) and a cutting head (206). A cutting edge (220) is formed on the cutting head (206). The cutting edge (220) includes at least one cutting portion. A rake surface (224) is formed adjacent to at least one of the cutting portions (220) with the rake face being at a rake angle in the range from about −10° to about 10°. A clearance face (226) is formed adjacent to the at least one cutting portion opposite the rake face (224). The clearance face (226) is at a clearance angle in the range from about 10° to about 50°. An edge radius between the rake face and the clearance face is at a radius of from about 0.0003 to about 0.0040 inch.

Abstract: A cutting tool (500) has a longitudinally extending shaft portion (588) with a chucking part (509) and a cutting head (506). A pressed powder cutting insert (518) with a cutting edge (520) is on the cutting head (506). The cutting edge (520) includes at least one cutting portion. A rake surface (524) is formed adjacent to at least one of the cutting portions (520) with the rake face (524) being at a rake angle from about 0° to 10°. A clearance face (526) is formed adjacent to the at least one cutting portion opposite the rake face (524). The clearance face (526) is at a clearance angle from about 10° to 50°. An edge radius (540) between the rake face (524) and the clearance face (526) is at a radius of from about 0.0015 to about 0.004 inch. The edge radius 540 is formed during pressing of the powder to form the insert, thus, enabling the insert to be directly braised into the cutting head (506).

Abstract: A cutting tool, especially a drill, milling cutter, screw tap, reamer and core drill, comprising a shaft and a cutting member on which at least one cutting edge is provided for machining a workpiece, the cutting member being provided with a slide layer which has a lower hardness than a base layer of the cutting member.

Abstract: A drilling tool, in particular a rock drill, is proposed, which is formed from a drill head, a clamping shank and a helical shank which is located between them. In order to produce a cost-effective drilling tool, the initial material used is a polygonal profile which is provided with a conveying helix groove in the region of the helical shank.

Abstract: A complex cutting-blade tool wherein a neck having a smaller diameter than the diameter of the drill thereof is connected to a shank. At the place where the drill and the neck are connected is provided a burr removal cutting blade inclined roughly 45° from the tool center axis. A hole entrance beveling cutting blade is also mounted through fixture to the neck, inclined at an angle of roughly 45° from the tool turning center axis, in a direction opposite to the burr removal cutting blade. The fixture can be secured at any position along the length of the neck, wherefore the distance between the burr removal cutting blade and the hole entrance cutting blade can be suitably adjusted so as to correspond to the depth of the machined hole (i.e. the thickness of the workpiece).

Abstract: A twist drill includes a shank which defines a longitudinal center axis and has a helical, chip-transporting flute formed therein. A cutting insert is arranged at a front end of the flute. The insert includes a body forming a cutting edge and a flank surface arrangement situated behind the cutting edge. The flank surface arrangement includes first and second flank surfaces extending at respective first and second acute angles relative to a reference plane which contains the center axis. The sizes of the first and second acute angles are different from one another. In one embodiment, each of the first and second flank surfaces intersects the cutting edge. In a second embodiment, only the second flank surface intersects the cutting edge, with the first flank surface extending from a rear end of the second flank surface.

Abstract: Significantly improved resistance to breaking while drilling in metal can be realized in twist drill bits having a web thickness taper which is about twice the web thickness taper specified in Standards and in common use in the industry. This creates much shallower flutes and flies in the face of conventional wisdom in the art which holds that the web taper rate should be low to maximize the amount of flute volume available to convey chips and sawdust out of the hole. A flute length of about 1/2″ less than the flute lengths specified by the Standards makes it possible to have such a large taper rate but still control variations in tolerances for the flute length. It also provides a marking zone for placing size indicia on the drill bit shank outside the portion which is gripped by the chuck jaws of a power drill.

Abstract: An end-mill tool has at least one low helix angle flute, or primary flute) and at least two low helix angle flutes, or secondary flutes. The primary and secondary flutes intersect to define a plurality of compound helical cutting surfaces. Each of the compound cutting surfaces includes a cutting edge having a leading portion formed adjacent one of the primary flutes and a trailing portion formed adjacent one of the secondary flutes.

Abstract: A cutting tool (200, 202) has a longitudinally extending shaft portion (208) with a chucking part (204) and a cutting head (206). A cutting edge (220) is formed on the cutting head (206). The cutting edge (220) includes at least one cutting portion. A rake surface (224) is formed adjacent to at least one of the cutting portions (220) with the rake face being at a rake angle in the range from about −10° to about 10°. A clearance face (226) is formed adjacent to the at least one cutting portion opposite the rake face (224). The clearance face (226) is at a clearance angle in the range from about 10° to about 50°. An edge radius between the rake face and the clearance face is at a radius of from about 0.0003 to about 0.0040 inch.

Abstract: The present invention provides an end-mill tool which includes a shank, a point, and a main body portion located intermediate the shank and the point. A first flute is formed on the main body portion along a first helix. A second flute is formed on the main body portion along a second helix. The first and second flutes preferably extend helically along the body of the tool. Two distinct helical cutting surfaces are defined by the first flute and the second flute. The point of the tool includes two additional cutting edges formed by ears extending outward from the point of the tool adjacent the first flute and the second flute.

Abstract: Proposed is a drilling tool for drilling in solid material, having a base body (1) containing chip flutes (5, 5a) and at least two interchangeable inserts (3, 3a) at the face of the base body (1). The inserts are arranged on the base body at different radial distances such that their working ranges partially overlap. The blades (12) of the inserts (3, 3a) are formed by two cutting edges (8, 9) which together form an obtuse angle, that is the point angle (11). The face (13) of the blades (12) has parallel profile ribs (14, 14a) which act as runners and which in the region of the cutting edges (8, 9), aligned in the direction of chip removal, extend radially inwards over a curved course relative to their installed position, toward a flank region (17) of the insert (3, 3a) near the drilling tool axis (7).

Abstract: A machining tool and method of making same includes a blank that is formed to a shank and which is provided with machining faces. The machining faces are configured to expose material of a PCD or PCBN element that is formed in a recess in the blank and fused to the blank using material from the transition group of elements, such as cobalt. The recess has a configuration that is defined by side walls, a base wall, and end walls, so as to define a mold in which the PCD or PCBN material is formed into an element that becomes fused with the blank. Such fusing is achieved by leaching of the cobalt into the PCD or PCBN element during the application of heat. Thus, no additional fabrication process is required for joining the PCBN or PCD material to the blank.

Abstract: A helical twist drill has fluted lands each having projecting from their radially outer faces a plurality of circumferentially spaced support margins. At least one of the support margins is asymmetrically spaced with respect to the other support margins.

Abstract: The following invention relates to a drill bit that will drill a round and precisely sized hole when using a hand-held drill motor. The bit has a unique multi-angle lip relief that cuts faster than a standard drill bit and stays sharp longer as well.

Abstract: A drilling tool includes a tool head having at least one chip groove and a tool shank. A slotted sleeve is placed on the tool shank and closely surrounds the chip groove. The edges adjacent the slot lie on solid material of the tool shank. The chip grooves and the sleeve form channels for carrying away the chips removed at the workpiece machining base. Owing to the slot, the sleeve can be gently spread apart and pushed onto the tool shank from the end having the enlarged tool head.

Abstract: A roll-forged drill bit 1 comprising a shank 3 for insertion in a chuck of a drill, the shank 3 including an helically twisted web 7 defining a cutting tip 9, the cutting tip 9 including a central chisel edge 11 and a cutting edge 15 defining the maximum diameter of the cutting tip 9, wherein the cutting tip 9 is formed after the shank 3 has been roll-forged and includes a pair of faces 13 defining the chisel edge 11 and a pair of upturned flats 17 defining the cutting edge 15. A roll-forged drill bit 1 according to the present invention provides a significant improvement in cutting speed over known prior art roll-forged drill bits.