Abstract: A drill bit for forming a round hole in a workpiece, includes a cylindrical shank having a longitudinally extending fluted portion with opposed first and second ends, and defining a longitudinal axis about which the shank is rotatable. The fluted portion includes opposed helical flutes formed in the cylindrical surface of the fluted portion of the shank and extending longitudinally along and between the first and second ends of the fluted portion. The helical flutes each define a concave surface intersecting with the cylindrical surface of the shank to form opposed flute edges. The first end of the fluted portion includes a cutting tip intersecting the helical flutes, wherein at least one of the flute edges has a concave cross-section extending from the second end toward the first end of the fluted portion.

Abstract: An instrument comprising a shank and a working portion, the working portion having a tip and a plurality of flutes being defined by at least two lands having a land margin; wherein the working portion has a parabolic cross-section defining opposing convexed surfaces extending between at least two opposing land margins.

Abstract: An auger includes a body with a first end, a second end opposite the first end, a stem that extends from the first end to the second end and defines an axis of rotation, and a flute helically wrapped around the stem. The auger further includes a shank at the first end of the body configured to be received by a power tool and a cutting head at the second end of the body. The cutting head includes a cutting edge, a spur, and a feed screw with a thread. The thread has a pitch and a nonsymmetrical thread profile. The pitch of the thread is at least 2.5 mm.

Abstract: A rotary cutting tool having an axis of rotation, a shank area, and a cutting area. The rotary tool has chip flutes reaching as far as a core profile in the cutting area. In order to reduce vibrations of the rotary cutting tool and therefore to permit precise machining and high surface quality with long service lives, the center line of the core profile has a course that deviates from the axis of rotation of the rotary cutting tool and/or the core profile contains mutually alternating sections with increasing cross-sectional area and sections with decreasing cross-sectional area over the length of the cutting area.

Abstract: A drill bit configured for use with a rotary power tool including a chuck. The drill bit includes a shank including a first end and a second end, and a paddle that extends from the second end of the shank. The paddle includes a first face including a concave portion, a second face opposite the first face and the second face including a convex portion opposite the concave portion, a cutting surface, a cutting edge located at an end of the cutting surface, a relief angle defined by the cutting surface, and an angled rake face adjacent the cutting surface that defines a rake angle that is between about 5 degrees and about 45 degrees.

Abstract: An auger bit includes an elongated shaft, a cutting bit, a feed screw, and a locking fastener. The shaft includes a flute extending in a helical manner with respect to a longitudinal axis along at least a portion of the shaft. The shaft further includes a first slot and a second slot. The first slot extends parallel to the longitudinal axis proximate the first end and is aligned with the axis. The cutting bit is removably received in the second slot and includes a first edge. The feed screw includes a shank and a threaded portion. The shank is removably received in the first slot. The feed screw engages the cutting bit to secure the cutting bit relative to the shaft. The locking fastener is coupled to the shaft and engages the shank of the feed screw to secure the feed screw relative to the shaft.

Abstract: A coupling part structured to engage with a complementary coupling part for interchangeably fastening a cutting head to a carrier of a rotary cutting tool. The coupling part includes a pair of coupling pins arranged opposite each other with respect to a central longitudinal axis and spaced apart from each other so as to form a receiving space structured to receive a central pin of the complementary coupling part. Each coupling pin includes a stop surface for transmitting a torque, a radially external outer surface, and a radially internal inner surface. At least one of the outer surface or inner surface is a clamping surface oriented in an obliquely inclined manner with respect to the central longitudinal axis for centering and clamping the coupling part.

Abstract: The present invention relates to the field of manufacture of miniature drills and discloses a miniature drill, which includes a drill body, a drill tip formed at one end of the drill body, and a plurality of spiral chip slots spiraling on a surface of the drill body; the chip slots include a long chip slot, a short chip slot, and a communicating chip slot, the long chip slot and the short chip slot are arranged at intervals and have the same helix angles, and the long chip slot is communicated with the short chip slot by the communicating slot.

Abstract: A drill bit configured for use with a rotary power tool including a chuck. The drill bit includes a shank including a first end and a second end, and a paddle that extends from the second end of the shank. The paddle includes a first face including a concave portion, a second face opposite the first face and the second face including a convex portion opposite the concave portion, a cutting surface, a cutting edge located at an end of the cutting surface, a relief angle defined by the cutting surface, and an angled rake face adjacent the cutting surface that defines a rake angle that is between about 5 degrees and about 45 degrees.

Abstract: A boring bit includes a shank and a drilling head coupled to the shank. The drilling head includes a center tip and a pair of flanges. Each flange includes a cylindrical sidewall section, a cutting edge extending radially outward from the center tip to the sidewall section, a bottom face extending radially outward from the shank to the sidewall section, a rake face extending axially from the cutting edge to the bottom face, a rearward edge extending radially outward from the shank to the sidewall section and defining a boundary of the bottom face opposite the rake face, a spur extending axially from the sidewall section, and a chip channel defined at least in part by the sidewall section. The sidewall section of each flange extends through a sweep angle from the cutting edge to the rearward edge. The sweep angle is between about 30 degrees and about 60 degrees.

Abstract: A cutting tool including a body, a blade, a feed shaft, and a locking member. The body defines an axis and is adapted to be received by a spindle of a power tool. The blade is removably supportable on the body and rotatable about the axis for cutting a workpiece. A feed shaft is removably supportable in the body and rotatable about the axis for engaging a workpiece, the feed shaft being mountable in the cutting tool to engage and at least partially restrain the blade. The feed shaft further includes an opening transverse to the axis. The locking member is engageable with the body and with the opening in the feed shaft. Advancement of the locking member into the opening tightens both the blade and the feed shaft to the body.

Abstract: A cutting tool including a body, a blade, a feed shaft, and a locking member. The body defines an axis and is adapted to be received by a spindle of a power tool. The blade is removably supportable on the body and rotatable about the axis for cutting a workpiece. A feed shaft is removably supportable in the body and rotatable about the axis for engaging a workpiece, the feed shaft being mountable in the cutting tool to engage and at least partially restrain the blade. The feed shaft further includes an opening transverse to the axis. The locking member is engageable with the body and with the opening in the feed shaft. Advancement of the locking member into the opening tightens both the blade and the feed shaft to the body.

Abstract: Drill bits comprising a shaft having a proximal end, a distal end, and a longitudinal axis extending between the proximal end and the distal end; and a cutting head located at the distal end of the shaft, having a cutting diameter, and having at least one flute, which includes a cutting edge and an offset leading spur are disclosed. A portion of the shaft of the drill bits located adjacent and proximal to the cutting head has a reduced diameter relative to the remainder of the shaft. The drill bits have a tapered point along the longitudinal axis at the distal end of the cutting head for guiding the drill bit or are cannulated to receive a guide wire.

Abstract: A shank that has one end adapted to be connected to a chuck of a rotary tool. The opposite end of the shank supports a cutting head having a series of teeth formed on the edge thereof for cutting the periphery of the hole. A screw tip may be provided for feeding the bit into and through the wood. A plurality of cutting blades are provided for boring the interior of the hole. The cutting blades define a plurality of cutting edges that are disposed at different angles to a plan perpendicular to the axis of rotation.

Abstract: The self feeding drill bit comprises a shank that has one end adapted to be connected to a chuck of a rotary tool such as a drill or power driver. The opposite end of the shank supports a cutting member where the cutting member is a cup shaped member having a series of teeth formed on the edge thereof. A screw tip is provided for feeding the cutting member into and through the wood. A removable cutting blade is provided for boring the interior of the hole. A kit including a self feed bit and a plurality of replacement bits is also provided.

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 boring bit includes a shank and a drilling head coupled to the shank. The drilling head includes a center tip and a pair of flanges. Each flange includes a cylindrical sidewall section, a cutting edge extending radially outward from the center tip to the sidewall section, a bottom face extending radially outward from the shank to the sidewall section, a rake face extending axially from the cutting edge to the bottom face, a rearward edge extending radially outward from the shank to the sidewall section and defining a boundary of the bottom face opposite the rake face, a spur extending axially from the sidewall section, and a chip channel defined at least in part by the sidewall section. The sidewall section of each flange extends through a sweep angle from the cutting edge to the rearward edge. The sweep angle is between about 30 degrees and about 60 degrees.

Abstract: A spade bit includes a shaft defining an axis, and a blade attached to the shaft and having a first blade portion and a second blade portion. The first blade portion defines a first leading face portion, and the second blade portion defines a second leading face portion. The first blade portion defines a first cutting edge portion, and the second blade portion defines a second cutting edge portion. The first cutting edge portion lies on a first border portion of the first leading face portion, and the second cutting edge portion lies on a second border portion of the second leading face portion. The first cutting edge portion and the second cutting edge portion both lie in a plane P1. An area A1 is bound by the plane P1 and the first leading face portion when the first blade portion is viewed in a first cross section taken along a plane P2 which is parallel to and spaced apart from the axis by a distance D1, and the area A1 increases as the distance D1 increases.

Abstract: An auger bit includes a shaft having a central axis, a cutting insert mounted to said shaft, and a feed screw that is separate from the cutting insert and which is mounted to the shaft. The cutting insert and the feed screw are engaged with each other. A single locking member, such as a set screw, secures the feed screw member to the shaft, and thereby secures the cutting insert to the shaft. If the feed screw or the cutting insert become worn, feed screw or the cutting insert can be replaced.

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 tissue cutting instrument includes an outer member, an inner member received within the outer member, and a cutter coupled to the inner and the outer members such that rotation of the inner member about an axis causes off-axis movement of the cutter. A method of cutting tissue includes positioning an outer member such that the outer member is adjacent tissue, engaging the tissue with a cutter coupled to the outer member, and moving the cutter to end-on cut the tissue. The extended portion of the cutter extends distally beyond a terminal end of the outer member.

Abstract: A cutting tool for a power tool. The cutting tool can include a tool body having a first end and a second end and an axis extending therebetween. The second end of the tool body can be engageable with the power tool. A feed screw can be supported in the tool body and can extend outwardly beyond the first end to engage a workpiece. A cutting blade can be removably supported in the tool body for engaging the workpiece.

Abstract: A spot drilling tool includes a drill holder and an insert removably mounted to the holder. The insert is a standardized part configured to support a drill point in a predetermined position forward of the drill holder and centered on the rotational axis of the drill holder. The drill point has two flutes and two substantially conical land surfaces extending between the flutes. The land surfaces have centers of curvature offset from the rotational axis of the insert to provide radial clearance for the trailing portion of the land. A chisel edge at the tip of the drill point is supported by a tapered web defined between the diagonally opposed and offset flutes. Linear cutting edges are formed at the junction of a planar flute surface and the conical land surface. The cutting edges define a narrow included point angle of between 50° and 80°.

Abstract: A spade bit includes a shaft defining an axis about which the spade bit is configured to be rotated. The space bit also includes a blade attached to the shaft and having a first paddle portion and a second paddle portion. In addition, the spade bit includes a tip portion attached to the blade and aligned with the axis. The first paddle portion includes (i) a first leading end portion positioned on a first side of the axis and configured to define a first cutting edge portion, and (ii) a first lateral extension portion configured to define a first sloping surface. The first paddle portion defines a first relief space positioned adjacent to both the first sloping portion and the first leading end portion. The second paddle portion includes (i) a second leading end portion positioned on an opposite second side of the axis and configured to define a second cutting edge portion, and (ii) a second lateral extension portion configured to define a second sloping surface.

Abstract: A bit including a shaft defining an axis about which the bit is configured to be rotated. The bit further includes a blade having a first end attached to the shaft and an opposite second end, the blade further having (i) a first blade portion including a first shoulder defining a first cutting edge portion at the second end of the blade, and (ii) a second blade portion including a second shoulder defining a second cutting edge portion at the second end of the blade. The bit additionally includes a frusto-conically-shaped tip portion having an apex and being attached to the second end of the blade. The frusto-conically-shaped tip portion includes threads extending from the apex to a location adjacent to the first cutting edge portion and the second cutting edge portion.

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 wood boring bit for boring holes in wood and other similar work surfaces having a central longitudinal axis, a main body, a pilot screw tip and a partial flute with a cutting edge and a cutting spur. The flute portion may be defined by a partial helical section having a distal end joined to the main body and a lead edge disposed toward said screw tip. The distal end and the lead edge preferably do not overlap along the central axis and are equal to or less than 360° from one another around the axis. The partial flute provides improved waste removal and allows the user to access the cutting edge of the flute for maintenance purposes.

Abstract: A spade bit including a longitudinally extending shaft having a cutting member located at a distal end thereof. The cutting member comprises a pair of helically shaped, opposed blades joined along the longitudinal axis of the shaft and an axially extending pilot spur. The pilot spur defines a pair of cutting edges, and each of the blades defines a forward cutting edge joined with a respective cutting edge of the pilot spur.

Abstract: A spade drill bit has a shaft and a spade head portion arranged on the shaft. The head portion has a rearward facing bottom edge, two longitudinal sides and a forward facing cutting edge. The cutting edge has a pointed, generally triangularly shaped tip and outer ends. The longitudinal sides of the head portion are bent along a bend in a direction of rotation of the drill bit during operation, so that the outer ends are bent forwards in the rotating direction. The bend runs from a first position at one of the longitudinal sides, closer to the bottom edge than to the cutting edge, and to a second position at the cutting edge between the outer end and the tip.

Abstract: The present invention to provide a high performance and versatile drill bit, for drilling curved bores, milling, countersinking and other application. A drill bit comprises a crown and a shank extending from the crown, wherein the crown comprises at least three cutting blades.

Abstract: The invention relates to a drill, especially a Forstner bit or a multi-spur machine bit having a drill shaft and a cutter head and provided with a central mandrel, a first and second spur cutter radially extending towards the outside from said mandrel and in opposite tool approach directions; a respective hollow cylinder segment wall has a circumference cutter defining the circumference of the cutter head and is joined to the ends of the first and second spur cutter, said ends facing the circumference, wherein the wall defines a chip space facing away from the spur cutter and opening to the respective remaining spur cutter and leading to the drill head, and wherein the two cutters are provided with wave-shaped cavities and elevations at least partially along the sides thereof.

Abstract: A boring bit includes a body having a spirally formed flute in an outer periphery thereof and a tool engaging end is connected to a first end of the body. A recess is axially defined in a second end of the body and a radial threaded hole is defined radially in the body and communicates with the recess. A lead portion has an engaging portion on a first end thereof and a threaded lead screw on a second end of the lead portion. The engaging portion is received in the recess and a bolt is engaged with the threaded hole and contacts the engaging portion. The threaded lead screw is easily replaced by removing the bolt.

Abstract: In a cylindrical drill bit comprising a tool body with a head having a front face and a cylindrical shaft for chucking the tool body, a hard metal cutting plate structure is mounted on the front face of the head and includes cutting edges formed integrally with the hard metal cutting plate.

Abstract: In a cylindrical drill bit comprising a tool body with a head having a front face and a cylindrical shaft for chucking the tool body, a hard metal cutting plate structure is mounted on the front face of the head and includes cutting edges formed integrally with the hard metal cutting plate.

Abstract: A spade drill bit has a shaft and a spade head portion arranged on the shaft. The head portion has a rearward facing bottom edge, two longitudinal sides and a forward facing cutting edge. The cutting edge has a pointed, generally triangularly shaped tip and outer ends. The longitudinal sides of the head portion are bent along a bend in a direction of rotation of the drill bit during operation, so that the outer ends are bent forwards in the rotating direction. The bend runs from a first position at one of the longitudinal sides, closer to the bottom edge than to the cutting edge, and to a second position at the cutting edge between the outer end and the tip.

Abstract: A drill bit, includes a shank and a cutter head connected to the shank. The cutter head has a center point, and first and second cutting edges extending radially outwards from opposite sides of the center point, wherein the first and second cutting edges are formed along their radial extension with valleys and peaks in alternating disposition such that in relation to the center point, as viewed in radial direction, the valleys of the first cutting edge are arranged at locations where the peaks of the second cutting edge are disposed, and the peaks of the first cutting edge are arranged at locations where valleys of the second cutting edge are disposed.

Abstract: A self feeding drill bit for making a smooth bore in a workpiece has a spiral land and flute with a leading end carrying a centered lead screw. The leading end of the bit has a cutter extending from said lead screw to the circumference of the bit. Diametrically opposed to the cutter is an inscriber formed as a curved blade by the periphery of the leading land. In use, the inscriber makes a smooth surfaced cut in the workpiece with the cutter removing the remainder of the workpiece within the scribed cut.

Abstract: A modified Forstner type drill bit includes a shank and a drill head. The drill head includes a center brad, first and second radial cutters, first and second following rims and first and second chip channels. The center brad defines a longitudinal direction. The first and second of radial cutters extend radially from the center brad. The first and second following rims extend circumferentially from and following from in the direction of rotation the distal end of the first and second radial cutters respectively. Each following rim is divided into a plurality of segments, each have a top portion. The top portion of the segments of each following rim are generally in the same plane. The first and second chip channels are positioned adjacent to and before in the direction of rotation the first and second radial cutters respectively. The first and second chip channels are between the one of the first and second radial cutter and the second and first following rims.

Abstract: A wood boring drill bit assembly includes a cast cutting head body having a front cutting portion, a rear connecting portion and a central longitudinal axis extending from the front portion to the rear portion. A stem extends axially rearward from the rear connecting portion. A pair of helically-shaped wings extend from the front cutting portion in opposed radial directions along the longitudinal axis. Each wing has an axially forward surface, a side surface, a trailing surface, and a machined cutting edge. The cutting head body has a tapered surface extending from the side surface of each wing to the rear connecting portion near the stem to allow for smooth retraction of the cutting head body from a drilled hole.

Abstract: A drill bit, includes a shank and a cutter head connected to the shank. The cutter head has a center point, and first and second cutting edges extending radially outwards from opposite sides of the center point, wherein the first and second cutting edges are formed along their radial extension with valleys and peaks in alternating disposition such that in relation to the center point, as viewed in radial direction, the valleys of the first cutting edge are arranged at locations where the peaks of the second cutting edge are disposed, and the peaks of the first cutting edge are arranged at locations where valleys of the second cutting edge are disposed.

Abstract: A wood coring bit having a base, a central guide shaft, a sleeve extending along the guide shaft, a pair of scribing teeth on the surface of the sleeve adjacent to the work piece, which scores a track into the work piece as the bit rotates and raker tooth on the surface of the sleeve adjacent of the work piece which is aligned to follow in the track scored by the scribing teeth and to cut and lift out the wood from the scored area. A helical slot extends through said sleeve from the raker tooth to receive the chip. A shank aligned with the guide shaft is used to connect the bit to a drill.

Abstract: A cylindrical head boring tool (1), such as a Forstner drilling tool, with a main cutting edge (4) having a centering point (5). The main cutting edge extends diametrically across the entire circular cross-section of the boring head (3), the main cutting edge (4) having cut out surfaces (11), and chip channels (7) adjacent the main cutting edge (4). The chip channels (7) open through the outer periphery and extending obliquely through the boring head (3). Each end of the main cutting edge (4) is adjacent a preliminary cutting edge (8) coinciding with the circumference of the boring head (3) for guiding the boring tool (1). The preliminary cutting edge (8) reaches to the edge of the respective other chip channel (7) and forms the peripheral edge of an essentially cylindrically curved wall (6) of the boring head (3). The otherwise smooth wall (6) is interrupted by radial throats (13).

Abstract: A milling cutter is provided including a tool holder and a cutting tool insert. The tool holder includes a mounting end portion and a cutting end portion. The cutting end portion includes a slot defined by first and second diagonal surfaces provided in an end of the cutting end portion. The first and second diagonal surfaces form a substantially V-shaped pocket for receiving the cutting tool insert. The cutting tool insert includes a substantially flat body member having a first side having a cutting surface on one edge thereof and a second identical side having a cutting surface on one edge thereof. A hole is provided through the body member from the first side to the second side. First and second surfaces are provided adjacent and substantially perpendicular to the first and second sides. The first and second surfaces define a V-shaped seat portion for seating the cutting tool insert in the V-shaped pocket of the tool holder.

Abstract: The present invention comprises a wood bit for use in wood working applications. The blade of the bit is generally spade shaped having cutting spurs on each corner of the blade, a central point projecting from the leading end of the blade, and hooked cutting edges.A progressive transfer die is used to bend the leading end of the blade and forge a continuous hook angle extending along the side cutting spur, the lateral shoulder, and the central point of the blade. The forging of a hook extending from each side of the blade converging at a central point provides a hook along the leading end of the blade projecting outwardly (in the direction of rotation) past the plane of the blade face. The leading end of the hook is beveled forming a continuous cutting edge extending along the hook from the outer side wall of the blade through the outside cutting spurs, along the lateral shoulders, and along each side of the central point.

Abstract: A cylindrical bit including a drill head with a centering tip, two circumferential cutters, two main cutting edges extending approximately radialy, and two chip channels associated with main cutting edges. The chip channels are open toward a circumferential surface and toward a rear of the cylindrical bit. To improve chip removal, each chip channel bottom surface is rounded in a curved fashion and blends continuously with the respective chip surfaces of the corresponding main cutting edges and with chip channel side walls opposite the respective chip surfaces.

Abstract: The present invention comprises a wood bit for use in wood working applications. The blade of the bit is generally spade shaped having cutting spurs on each corner of the blade, a central point projecting from the leading end of the blade, and hooked cutting edges.A progressive transfer die is used to bend the leading end of the blade and forge a continuous hook angle extending along the side cutting spur, the lateral shoulder, and the central point of the blade. The forging of a hook extending from each side of the blade converging at a central point provides a hook along the leading end of the blade projecting outwardly (in the direction of rotation) pass the plane of the blade face. The leading end of the hook is beveled forming a continuous cutting edge extending along the hook from the outer side wall of the blade through the outside cutting spurs, along the lateral shoulders, and along each side of the central point.

Abstract: A throw-away tipped drill has an insert removably connected to a shank for cutting a workpiece. The insert (31) and the shank (32) have mutually engaging surfaces respectively, and a slit (34, 39) is formed either in the insert (31) or in the shank (32) for mounting the insert to the shank, whereby the insert (31) is fixed to the shank (32) by an elastic force which is caused by an elastic deformation upon mutual movement of opposite surfaces of this slit (34, 39) in engagement of the insert (31) and the shank (32). Therefore, the insert (31) and the shank (32) are coupled by simple press fitting without any requirement for a screw or other connection, whereby the assembly is improved.

Abstract: A spade-type drill bit is disclosed having a shank portion and a spade bit portion extending from the shank portion. The spade bit portion includes a spade portion with a planar region, and a center tip concentric with a longitudinal axis and extending from the spade portion. First and second radial cutting edges extend from the center tip toward first and second corner tips. First and second longitudinal cutting edges extend along longitudinal sides of the spade portion and terminate at the first and second corner tips. The first and second corner tips are located forward of the plane of the spade portion in the direction of rotation of the drill bit. The first and second radial cutting edges, and the first and second longitudinal cutting edges further include curved portions adjacent each of the first and second corner tips. Threads may also be provided on the center tip.

Abstract: The subject of the invention is wood industrial drilling cutting tool for preparing holes mainly in wood and in the like sort, which holes can be used as blind holes for fastening together wooden constructions, furniture, toys etc. and which has one or more swarf-leading surface which is situated behind one or more main cutting edge which is continuously rising and reach the backside of the drilling body.The essence of the invention is that the swarf-leading surface is concave-courved seeing from the direction of bore rod, further, as a continuation of the swarf-leading surfaces a swarf-lifting spiral is formed on the bore rod.

Abstract: An improved drill bit for wood boring or boring in other relatively soft material, having a generally cylindrical shaft (20), with a flattened blade portion at one end (24). The blade portion (24) is broad and flat with essentially parallel side surfaces (41, 42) and having negatively beveled edges along the length of such side surfaces, such side surfaces giving way to a modified end edge. The modified end edge includes a center point, with a length of one half to several times the thickness of the blade, and said point (34) is centered on the end edge and is made with a triangular shape with a vee groove from the center of the base to the middle of the vertex. (35). Outer spurs of rectangular cross section (29 and 30) with a concave tip and a negative bevel away from the leading edge are located on the lateral extremities of the end edge.