Abstract: A rotary cutting tool that is composed of a tool shank with at least one chucking groove or chip flute and one exchangeable cutting insert. At the tip of the shank a recess for accommodating the cutting insert is provided. The tool shank, on its circumference, has a limb with a bearing surface that is inclined relative to the tool axis and that corresponds to a likewise inclined bearing surface on a wing of the cutting insert. The inclination of the bearing surfaces produces an axial force that retains the cutting insert on the tool shank. The abstract of the disclosure is submitted herewith as required by 37 C.F.R. §1.72(b). As stated in 37 C.F.R. §1.72(b): A brief abstract of the technical disclosure in the specification must commence on a separate sheet, preferably following the claims, under the heading “Abstract of the Disclosure.

Abstract: A method for forming at least one opening in a receptacle comprises the steps of providing a receptacle having a cover with an exterior surface and an interior surface covering a cavity. A cutting mechanism is also provided having at least one blade. The cover is pierced with the blade, and the blade is moved through the cover to cut a portion of the cover and create an opening in the cover to provide access into the cavity. Further, the cut portion curls on top of the exterior surface as the opening is created.

Abstract: In order to provide a rotary tool, in particular a drill, with a long service life together with high-quality drill holes, particularly in the case of through bores, the invention provides a cutting head which extends along a rotational axis and has a plurality of main cutting edges which extend radially outwards and each end at a cutting corner having a corner bevel, wherein the corner bevels are of differing designs, specifically in the form of a roughing bevel and in the form of a finishing bevel.

Abstract: A drill includes a pair of main cutting edges extending from a distal portion of the drill to a position close to a proximal end of the drill to entirely define a two-edge configuration, and a pair of auxiliary cutting edges extending between positions at the distal and proximal sides of a maximum diameter position to partly define a four-edge configuration. A ridgeline of each auxiliary cutting edge is located within an angle smaller than 90° from a ridgeline of the corresponding main cutting edge toward the rear in a rotation direction of the drill. The point angle of the auxiliary cutting edges increases at a higher rate than the point angle of the main cutting edges in a predetermined range from the maximum diameter position toward a distal end of the drill.

Abstract: The drill bit comprises a cutting blade formed at one end of a shank. The cutting blade has a pair of cutting shoulders that extend inwardly from the outer sides of the blade toward the bit axis. A tip having converging sides that create a point extends from the shoulders. The cutting edge of each shoulder is beveled with respect to the plane of the face of the blade. A flute is provided on the leading portion of each blade face adjacent the cutting edges. Each flute is a smooth curve that creates a substantially uninterrupted recess on each face of the blade that facilitates chip removal, increases the drill rate and lowers the power required to drill a hole. A non-stick coating may be applied to the blade to further facilitate chip removal.

Abstract: A cutting tip is coupled with a rotor, which operates in response to actuation of a motor, in order to cut or process a workpiece. The cutting tip includes a plurality of first cutting recesses formed in upper and lower edges of one face of the cutting tip, which comes in contact with the workpiece; and a plurality of second cutting recesses, alternating with the first cutting recesses in a plan view, the second cutting recesses having a conical shape. The first and second cutting recesses in the cutting tip can minimize the abrasion of the cutting tip when cutting workpiece, enhance cutting power, and increase lifetime.

Abstract: A masonry drill bit includes a cutting insert which is substantially roof-shaped in sideview and has on each side of its “roof” one lip. Each lip includes a leading cutting surface and a trailing free surface, wherein the mutually abutting free surfaces at the roof ridge define a chisel edge. Each free surface is concave in a sub-zone adjacent to the chisel edge in a manner that the radially outer ends of the chisel edge axially protrude at the end face of the insert relative to the in-between center of the chisel edge. Each lip includes at least one recess and to that extent deviates from the substantially roof-shaped geometry.

Abstract: Disclosed is a single-lip drill comprising a drill head (11) that is provided with a blade (12) which is embodied on said drill head. The blade encompasses a cutting edge (19) for machining a workpiece (16) in a cutting manner. At least one chip-forming device (21) which shapes chips (22) cut by the cutting edge is associated with the cutting edge. The chip-forming device is provided with a positive cutting angle (gamma) such that the mechanical and thermal stress can be reduced in the area of the blade (12). In addition, the chip-forming device can comprise a functional coating (29a, 29b) which is made especially of hard material and is applied after providing the drill with the exterior shape thereof.

Abstract: A machine reaming tool includes a reaming head or interchangeable head (1) and a shaft (2), wherein the interchangeable head (1) is of one piece and may be exchanged, and in an axial direction and at each location, thus including means for the exchange adaptation, is thinner than a maximal thickness hmax, wherein this maximal thickness hmax is computed in millimeters from a diameter D1 of the interchangeable head in millimeters as hmax=6 mm+(1/10)·(D1?12 mm). On account of this, a guide portion (18) for cutters of the reaming head (1) becomes very much shorter than usual, but despite this ensures an adequate quality of machining. In a preferred embodiment of the invention, the interchangeable head (1) in a plane shaft-side end-face (15) comprises cutout (11) for the centering fastening on the shaft (2).

Abstract: A support pad intended for metal machining drills and of the type that includes an outer surface, an inner surface, front and rear end surfaces, as well as a pair of spaced-apart side surfaces, between the outer surface and at least the front end surface a convexly arched entering surface being formed that extends between, on one hand, a pair of front and rear borderlines, the rear one of which borders the outer surface, and, on the other hand, two tangentially spaced-apart side borderlines. The rear borderline of the entering surface has the shape of a convex arc line as viewed in planar view toward the outer surface, more precisely an arc line the crest of which is facing forward. In such a way, the position of the contact of the support pad with a hole wall can be predetermined in an exact way. The drill body may be equipped with one or more support pads.

Abstract: A drill head extending along a drill axis made of hard metal for rock drills is disclosed. The drill head features at least one major cutting edge and at least one minor cutting edge, where the major cutting edge extends from a first radially inner end to a first radial outer end which lies on a first diameter and where the minor cutting edge extends from a second radially inner end to a second radially outer end which lies on a second diameter that is smaller than the first diameter. A first enveloping surface defined by the minor cutting edge projects completely axially over a second enveloping surface defined by the major cutting edge.

Abstract: The invention relates to a drilling tool, especially for percussion drilling, which comprises a cutting element (3) that is configured as a plate (3) or head and that has at least one cutting edge (11) defined by a cutting face (6) and a free face (10). The cutting edge (11) is associated with a first free face section (10a) which is limited in a cutting plane at a right angle to the cutting edge (11) and parallel to the longitudinal axis (L) of the drilling tool (1) by a convex bulge (13) or a convex polygon outline. The vertical height of a rib (14) defined by the first free face section (10a) and an associated first cutting face section (6a) ranges from 0.1 mm to 1.0 mm.

Abstract: A tool simultaneously deburrs and cleans an end of a pipe. The tool may have a casing that combines a mechanically abrasive cleaning mechanism and a cutting mechanism. The casing may have the cleaning mechanism and cutting mechanism aligned on an axis with the pipe, so that the outer surface of the pipe may be cleaned while the internal diameter may be cut or deburred. Some embodiments may be hand held devices that may be gripped in the palm of a hand, while other embodiments may be mounted on a drill or other powered mechanism.

Abstract: The present invention relates to a rotating instrument made of a ceramic material and comprising a shaft 1 and a working member 2 which is secured to the shaft or can detachably be secured thereto, wherein at least part of the working member 2 is made from a ceramic material, characterized in that the ceramic part of the working member 2 has a surface roughness of 0.5 ?m to 6 ?m.

Abstract: First and second bore blade portions are provided on the outer periphery of a rotary shaft at intervals in the circumferential direction with a rotation axis as the center. A first bore blade portion has a continuous blade and a second bore blade portion has a discontinuous blade having protruding blade edges and indented blade edges, which are alternately provided. The distance in the radial direction of the protruding blade edges is set so as to be greater than or equal to the distance in the radial direction of a continuous blade, and the distance in the radial direction of indented blade edges is set so as to be smaller than the distance in the radial direction of the continuous blade. Accordingly, the cutting resistance of the bore cutter can be reduced.

Abstract: A drill for chip removing machining, including a drill body, and a replaceable cutting insert mounted in a pocket formed in a front tip of the drill body. A chip flute extends backwardly from the pocket along the drill body, and the cutting insert is fixed in the pocket by a screw including a head and a shank having a male thread. The cutting insert includes a through hole extending between a topside and an underside. The hole has a basic shape that is rotationally symmetrical in relation to a center axis, and is delimited by a series of surfaces including a mouth surface, converging downward from the topside, and a shoulder surface. The head of the screw is kept pressed against the shoulder surface when the male thread of the screw is tightened in a female thread included in a hole that mouths in a bottom of the pocket. The mouth surface in the hole of the cutting insert has a trumpet-like, cross section-wise convex shape adjacent to the topside of the cutting insert.

Abstract: The invention concerns a wood drill bit with a cylindrical drilling head. The drilling head has at its end a centering tip which is disposed on the longitudinal axis of the drill bit and which projects in the drilling direction for centering the wood drill bit, at least two main cutters which are arranged diametrically and radially or substantially radially and have main cutting edges, and a pan-cylindrical guide bell. Adjoining each main cutter is a chip ejection space which is partially open towards the connecting portion. It is proposed inter alia that the main cutter extends with a radially inwardly disposed portion into the centering tip and the chip ejection space is enlarged into the centering tip by means of a pre-chip ejection groove.

Abstract: A drill bit for producing holes in composite materials is disclosed. The drill bit includes an elongate drill bit body having a drill bit diameter. The drill bit also includes at least two helical flutes. The helical flutes have a reverse helix angle and a primary cutting edge. The primary cutting edge may have a positive rake angle. The drill bit further includes a point having a point length. The drill bit may also include a cutting tip with a tip angle and a tip length. The tip length is at least twice the drill bit diameter.

Abstract: A drill bit has a cylindrical drill head (1) having two essentially diametrically situated primary cutting edges (2) and chip channels (3) associated therewith. The outer surface (5) of the drill head is formed by curved sections (6) whose end faces (4) have teeth (8) which extend in the axial direction (A) and have cutting edges (7) and cutting faces (9). The cutting faces (9) run at an acute angle in the cutting direction (S) and are set back with respect to a radial line (L) passing through the cutting edge (7). The teeth are formed by crenellated elements (8) which with one of their respective side walls form a cutting face (9) of the cutting edges (7). The side walls (10) of the adjoining crenellated element (8) opposite from the cutting face (9) runs parallel to the cutting face (9).

Abstract: The invention provides a drill head for deep hole machining capable of raising circularity and straightness of a hole and improving precision of hole machining. In the drill head for deep hole machining constituted by fixing a cutting blade to a tip surface of a head body and fixing guide pads to a periphery of a tip of the head body, the length Lm of a margin, which is formed at a tip side of a periphery of the cutting blade in a drill rotating direction, in an axis direction is made substantially the same as the length Lp of the guide pads in the axis direction, and a top end and rear end of the margin are substantially aligned with a top end and rear end of the guide pads, respectively, in a circumference direction.

Abstract: An orthopedic reamer for use in creating and sizing canals in a bone is disclosed. The orthopedic reamer includes a non-polymeric cutting portion having at least one cutting surface thereon and a polymeric body portion covering at least a portion of the cutting portion. The at least one cutting surface is not covered by the polymeric body portion.

Abstract: The present invention provides a new drilling tool useful in machining hydraulic port seals for fluid power ports. The drilling tool drills the port hole to size in a solid material for the minor thread diameter in combination with forming the port in a single operation. The drilling tool has a tool holder having a rotational axis, a first drilling insert having cutting surfaces on a first side and a mounting surface on a second side, at least one second drilling insert having a predetermined cutting surface portion and a mounting portion which is mounted on the holder at a location from the rotational axis of the holder. The at least one second drilling insert has first and second portions which engage and machine a work piece in a drilling operation to form a spot face and a seal form.

Abstract: A tool shank and a replaceable cutting insert are provided for a rotary cutting tool assembly. The tool shank has a drive surface including a central portion, a first portion of generally planar shape extending away from the central portion and a second portion of generally planar shape extending away from the central portion in a direction generally transverse to a central axis of the tool shank. The replaceable cutting insert has a driven surface including another central portion, a first portion of generally planar shape extending away from the other central portion and a second portion of generally planar shape extending away from the other central portion in a direction generally transverse to a central axis of the insert. The central portion of the driven surface has a curved surface transitioning between the first portion and the second portion of the driven surface.

Abstract: A cutting tool comprising: a rotatable hollow tube with an inlet at a distal end of the tube and a cutting edge at the perimeter of the inlet, the tube being arranged so as to rotate when in use so as to cut a work piece with the cutting edge; and an auger housed within the hollow tube, the auger being arranged so as to rotate when in use so as to feed cut material from the inlet along the hollow tube, wherein a distal end of the auger is set back from the cutting edge of the tube. A method of drilling a hole in a dry fibre assembly, the method comprising engaging the dry fibre assembly with a cutting tool comprising a hollow tube with an inlet at a distal end of the tube and a cutting edge at the perimeter of the inlet; and rotating the hollow tube so as to cut the dry fibre assembly with the cutting edge.

Abstract: Disclosed is a drilling tool comprising a first drill bit (2) that is provided with at least two forward cutting edges (4, 5) and a second drill bit (3) which encompasses at least two rear cutting edges (6, 7). A cutting groove (8, 9) runs continuously from one respective forward cutting edge (4, 5) to a rear cutting edge (6, 7). Said cutting groove (8, 9) is embodied in an asymmetric manner in an area (A) bordering the forward drill bit (2), in a symmetric manner in a central area (B), and asymmetric in an area (C) bordering the rear drill bit (3).

Abstract: A twist drill has double margins and a chisel edge angle of between 80 degrees and 100 degrees to maximize hole straightness and to minimize “walking” of the drill upon a workpiece. The drill may be modular having a removable tip body or the drill may be of a solid configuration. A tip body is consumable and may be removed and replaced as required.

Abstract: An improved cutting tool for drilling complex holes in a workpiece such as an automotive aluminum wheel, in which the tool has a shank and an integrally formed support section. A cutter insert secured in the support section. The cutter insert is formed with opposed flutes along the longitudinal axis of the tool. The tool is improved by reducing cutting forces and optimizing chip disposal, thereby cutting costs by reducing the load requirements for drilling holes, and this is accomplished by creating a positive rake angle at the flutes.

Abstract: One object of the present invention is to increase stability for fixing a cutting tool with a holder formed of a sleeve, and to improve machining accuracy of a boring tool using the holder and prevent chipping of a cutting edge. In a holder for a boring tool holding a bar-shaped cutting tool by receiving it in a center hole in a sleeve and clamping it with clamp means, the sleeve is provided with a slit cutting a region from the center hole in the sleeve to an outer periphery surface thereof lengthwise from a front end to a longitudinal partway portion of the sleeve, and is further provided with a fastener tightening a slit-formed portion of the sleeve to change an inner diameter of the center hole.

Abstract: A downhole deburring tool is equipped with retractable cutters which permit it to fit through restrictions in a wellbore—e.g., a subsurface safety valve—and subsequently expand to deburr or scrape a section of tubing having an internal diameter greater than that of the restriction. In one preferred embodiment, tapered surfaces on the tool act to effect retraction of the cutters during withdrawal of the tool from a wellbore. Deburring operations with the tool may increase the effectiveness of bridge plugs and/or ball sealer systems to permit chemical treatment of selected zones.

Abstract: A spade drill insert and drilling tool assembly is provided wherein the lands of the spade drill insert have helical margins which provide increased stability during cutting operations and the holder has a clearance surface providing better chip evacuation. The margin may have a helical trailing side or leading side, a parallel helical margin, or may also include a gullet or flute adjacent the helical margin.

Abstract: A toolholder for use in a metalworking operation, with a body extending along a longitudinal axis and a recess extending within the first end of the body. Adjacent an insert pocket adapted to receive a cutting insert in the recess is at least one wall with a portion having a surface with multiple interruptions to form a chip ejection segment. The chip ejection segment may be an integral part of the toolholder body or may be a discrete piece removably attached to the toolholder body. A method of imparting to a toolholder such a chip ejection segment is also disclosed.

Abstract: The invention relates to a machine tool, particularly a machine reamer, comprising a shaft-type base and a replaceable cutter head which frontally protrudes from the base. An axially protruding extension of said cutter head engages into a frontal receptacle that is fixed to the base, the cutter head being removably clamped in said receptacle by means of a clamping screw which penetrates the replaceable cutter head in a truly axial direction. The screw head of the clamping screw rests against a face of the replaceable cutter head. The extension of the replaceable cutter head is provided with a polygonal part which is complementary to a truly axial polygonal hole that is fixed to the base and is penetrated by the polygonal part.

Abstract: A drill bit, such as a twist drill, having a body equipped with flutes, as well as a drill bit face that includes two main cutting edges that merge together. In order to drill a blind hole, such as with a level drilled bottom, the main cutting edge forms a continuous cutting edge that runs in a plane perpendicular to the drill bit's longitudinal axis. The main cutting edges, with respect to a cutting direction, are arranged behind a center line lying in the plane which is perpendicular to the longitudinal axis of the drill and extending through the center of the drill as well as in the direction of the main cutting edges.

Abstract: The present invention discloses a rotary cutting tool which can maintain a secure coupling state between the shank and the cutting head and enhance the durability of the shank by preventing a damage of the shank and the cutting head from being generated.

Abstract: A cutting tool of the sort used for deep hole drilling has a cutting head mounted on a shank. The cutting head is formed asymmetrically with respect to a longitudinal axis and has at least one cutting edge. The cutting head has guiding segments that extend from a forward end to a rear end of the cutting head. Each of the guiding segments has a guiding pad in the periphery thereof. A forward end of the guiding pad lies on a cylindrical envelope defined by the cutting diameter of the cutting tool. A rear engagement portion of the cutting head is engaged with a forward engagement portion of the shank. The cutting head is made from sintered carbide powders and the guiding pads are integrally formed with the cutting head.

Abstract: A multi function attachment for a drill for use in building, construction, gardening, yard work, camping, and cooking activities that involve mixing, digging, churning, and stirring includes an elongated shaft securable to the receiving end of the drill, a safety handle slidably disposed upon the shaft and whose slidable movement is delimited by the receiving end of the drill and a handle stop fixedly mounted adjacent the distal end of the shaft, and a digger/mixer member mounted to the distal end of the shaft with the digger/mixer member including a plurality of fingers that project transverse to the axis of the shaft that engage the material, such as dirt or food items, to be dug up, churned, stirred, or mixed upon actuation of the drill.

Abstract: A surface-coated cutting tool includes a coating layer (108) formed on a substrate (104), wherein assuming that the average thickness of the coating layer (108) on a first surface (106) and a second surface (107) of the substrate (104) is A, a difference between the maximum and minimum thicknesses of the coating layer (108) is 0.04×A or less. Also, a surface-coated cutting tool includes a coating layer (108) formed on a substrate (104), wherein assuming that the average thickness of the coating layer (108) on a first surface (106) of the substrate (104) is B1, and the average thickness of the coating layer (108) on a second surface (107) of the substrate (104) is B2, a value obtained by dividing an absolute difference value between B1 and B2 by a larger value of B1 and B2 is 0.04 or less.

Abstract: A milling head for a milling device, particularly a rotary milling device, wherein the milling head is capable of imparting a desired finish on a tube, preferably of a heat exchanger tube. The milling head includes one or more milling elements capable of cutting and/or removing heat dissipating elements connected to an outer surface of the tube. The heat dissipating elements are removed from the tube in a longitudinal direction along the tube length. In one embodiment, the milling head also includes a bevel milling element. Methods for milling a tube having heat dissipating elements are also described.

Abstract: Methods of fly-cutting a workpiece are disclosed, and in methods in which the position of a fly-cutting head or its associated cutting element is known as a function of time. Also disclosed are methods of forming features, such as grooves or groove segments, in a workpiece such as a cylindrical roll. The features may be provided according to one or more disclosed patterns. Articles made using tools machined in the manner described are also provided, such as polymeric film or sheeting that exhibit certain beneficial properties.

Abstract: The invention relates to a multi-bladed deep drilling tool (17) comprising a cooling lubricant channel (19, 20) provided for each chip space (74) allocated to each cutter (71). Said channels (19,20) are supplied with a lubricant independently from each other, by means of either jointly drives or separately drives lubricating pumps (25, 26). Said channels being associated with either the drilling devise (11) or integrated into an adapter (30) which is pivoted with a common flow of lubricant, but which supplies independent individual flows. Lubrication of the individual cutting zones is guaranteed even if the chip removal channel is blocked, by chips for example. The pressure of the cooling lubricant channel increases in said area whereupon the channel in question is cleared.

Abstract: The drill bit comprises a cutting blade formed at one end of a shank. The cutting blade has a pair of cutting shoulders that extend inwardly from the outer sides of the blade toward the bit axis. A tip having converging sides that create a point extends from the shoulders. The cutting edge of each shoulder is beveled with respect to the plane of the face of the blade. A flute is provided on the leading portion of each blade face adjacent the cutting edges. Each flute is a smooth curve that creates a substantially uninterrupted recess on each face of the blade that facilitates chip removal, increases the drill rate and lowers the power required to drill a hole. A non-stick coating may be applied to the blade to further facilitate chip removal.

Abstract: A circular truncated cone-shaped cutting section (3) of a chamfering tool (1) is formed with a first blade section (31) which is tilted so that a chip is discharged to a side of a shank section (2), and a second blade section (32) which is tilted so that the chirp is discharged to a direction opposite to the side of the shank section (2) in a peripheral direction with a gap. The chamfering tool (1) is rotated, and the first blade section (31) and the second blade section (32) are alternately brought into contact with an edge of an object to be worked so that the edge is chamfered. As a result, occurrence of a secondary burr on the edge is suppressed.

Abstract: A fastener thread cleaning apparatus includes a first arm and a second arm each having a first end and a second end. The first and second arms are pivotally coupled together adjacent to the first ends to define a pair of jaws. An abutting side of each of the of the first and second arms is defined and abut each other when the pair of jaws is positioned in the closed position. Each of the of the abutting sides has a semi-circular depression therein. The depressions are alignable to define an aperture, which is threaded. The pair of jaws may be closed around a bolt to threadably engage the bolt with the aperture. The pair of jaws is positioned between a head and an end of the bolt and the bolt rotated to move the pair of jaws toward the end of the bolt.

Abstract: A drill for chip removing machining, including a drill body that rotates around a center axis (C1) and has a rear end, and a front end from which there extends rearward an envelope surface in which two chip flutes each having an insert pocket are countersunk, and two replaceable cutting inserts, including a peripheral cutting insert mounted in a peripheral pocket, and a center insert, which is indexable and mounted in a center pocket that opens in the front end of the drill body and is delimited by a bottom surface, a rear end support surface, a side support surface of a partition wall, and an inside of a border adjacent to the envelope surface. The center insert includes an upperside and an underside between which a through hole for a tightening screw extends, and has an elongate basic shape that is mirror-symmetrical in relation to an imaginary, longitudinal central plane (P) with which a center axis (C3) of the hole coincides.

Abstract: A drill includes a tip-forming front end having at least two straight cutting edges and at least two chip flutes extending from the tip end towards a rear end. Each cutting edge includes an inner portion disposed near a center line of the drill, and an outer portion disposed farther from the center line. The peripheral end of each cutting edge is in the form of a smoothly curved nose portion protruding radially with respect to the center line. The nose portion is formed by several circular segments having mutually different radii (R1, R2, R3). Adjacent ones of the radii are of different size.

Abstract: A one-piece drilling head (4), which is securable, in a material-locking manner, on an axial end of a helical shaft of a drill, is formed of a hard material and has four radially extending, in a cross-shaped manner, legs (5) forming respective cutting edges (6), and a tangential reinforcement (7) provided at a radially outer rim of each leg (5) in an axial region of a cutting edge (6).

Abstract: A milling insert and a milling insert tool for chip removing machining. The milling insert includes at least two teeth. The milling insert has substantially a disc shape and includes a topside and an underside. The milling insert in its entirety is formed of cubic boron nitride.

Abstract: Disclosed is a drilling tool comprising a first drill bit (2) that is provided with at least two forward cutting edges (4, 5) and a second drill bit (3) which encompasses at least two rear cutting edges (6, 7). A cutting groove (8, 9) runs continuously from one respective forward cutting edge (4, 5) to a rear cutting edge (6, 7). Said cutting groove (8, 9) is embodied in an asymmetric manner in an area (A) bordering the forward drill bit (2), in a symmetric manner in a central area (B), and asymmetric in an area (C) bordering the rear drill bit (3).

Abstract: A drill including a chisel edge provided at a tip end portion, a spiral first chip discharging groove and a spiral second chip discharging groove, land portions provided between the first chip discharging groove and the second chip discharging groove, and a cut blade provided at an edge of a rake surface of the first chip discharging groove, characterized in that the first chip discharging groove and the second chip discharging groove are provided asymmetrically with respect to a drill rotational center and a land portion behind the first chip discharging groove is larger than a land portion behind the second chip discharging groove.

Abstract: The invention relates to a countersink bit for composite wood. The countersink bit comprises a generally cylindrical body having at one end a cylindrical portion and at the other end an engagement portion. The countersink bit has a conical portion at an end of the enlarged cylindrical portion, and the conical portion comprises a shallow cutting face defined by a cutting edge and a bottom edge. The conical portion further comprises a shallow split surface, defined on one side by the bottom edge and on the other side by an edge of a flank. In the countersink bit, the split surface and the shallow cutting face define a reservoir which, in use, accumulates cut composite wood material.