Abstract: A pilot assembly having a shaped portion and a shaped fastener relief for attachment to a die. The pilot assembly includes a fastener with a shaped washer that engages the shaped fastener relief to permit installation and removal of the pilot from the die. The shaped portion of the pilot assembly helps to locate and center the stock down the pilot assembly toward the die.

Abstract: A drill may be extended from a first end to a second end and may include a cutting part. The cutting part may include a cutting edge, a flute, an end surface and a connection surface. The flute may be extended from the cutting edge toward the second end. The end surface may be located closer to the second end than the flute. The connection surface may be located between the flute and the end surface. The connection surface may include a first portion, and a second portion located closer to an outer periphery of the cutting part than the first portion. A length in the direction along the rotation axis on the second portion may be smaller than a length in the direction along the rotation axis on the first portion in a side view orthogonal to the rotation axis.

Abstract: A cutting head rotatable about a first axis, has a cap portion and a rigid mounting protuberance joined thereto. The cap portion has a plurality of cutting portions circumferentially alternating with a plurality of head chip flutes, and a head base surface facing in an axial rearward direction. The mounting protuberance exhibits rotational symmetry about the first axis, extends axially rearwardly from the head base surface, and has a plurality of circumferentially spaced apart convex clamping surfaces. The plurality of cutting portions define a cutting diameter, the plurality of head chip flutes are inscribed by an imaginary first circle having a first diameter, and the plurality of clamping surfaces are circumscribed by an imaginary second circle having a second diameter. The first diameter is greater than the second diameter, and the second diameter is less than forty percent of the cutting diameter.

Abstract: A rotary cutting tool includes a cutting head and a tool shank, each having an axial abutment surface and a plurality of drive surfaces. One of the two includes a locating pin, while the other includes a pin receptacle and at least one clamping through bore that opens out to the pin receptacle. The locating pin is received into the pin receptacle. The cutting head and tool shank are releasably clamped together by at least one clamping member that passes through the at least one clamping through bore and acts on the locating pin so that the drive surfaces and the axial abutment surfaces on each part abut each other.

Abstract: Methods and constructs for soft tissue to bone repairs employing tensionable knotless anchors, without knot tying. The tensionable knotless anchors may be used by themselves or in combination with additional constructs (which may have a similar or different configuration, i.e., modified according to the specific repair) and with the flexible strands provided through tissue, around tissue, or through and around tissue to be repaired or fixated.

Abstract: A cutting head having a cutting end and an opposite coupling end along a longitudinal cutting head axis; having a cutting head length; and including two major surfaces and a peripheral surface. A male coupling portion extends rearwards from the coupling end, between a base portion and a rear surface, with a circumferential peripheral surface, having a coupling length. A flexibility slot extends from the rear surface opening to the major surfaces, along the cutting head axis, having a slot length and a head slot length. The coupling length is equal to or less than half the head slot length, and the slot length is equal to or greater than half the cutting head length. The cutting head is self-clamped into a tool shank with female coupling portion, by a friction fit between the male and female portion peripheral surfaces, causing the cutting head to elastically deform.

Abstract: A guide pad for a cutting tool is formed with at least one sliding surface, which is convexly curved in a plane perpendicular to a longitudinal axis of the guide pad. Each sliding surface includes two convexly curved sliding sub-surfaces separated by a fluid conveying formation having a longitudinal extension in a direction in parallel to the longitudinal axis. The fluid conveying formation is planar or has a convexly curved shape in a direction perpendicular to the longitudinal axis having a larger radius of curvature than the radius of the sliding surface.

Abstract: The modular carrier tool (2), in particular drilling tool, extends along a central longitudinal axis (4) in axial direction (6) and comprises a carrier (8) as well as a tool head (10) that can be reversibly mounted on the front-end of the carrier (8). The carrier (8) has a head retainer (14) for the insertion of the tool head (10) as well as clamping webs (24), which radially delimit the head retainer (14) and also have bearing surfaces (28). The tool head (10) comprises clamping surfaces (35) extending in axial direction as well as underhead bearing surfaces (34). In a mounted state the clamping webs (24) clamp the tool head (10) in radial direction to the clamping surfaces (35) and the underhead bearing surfaces (34) are pressed against the bearing surfaces (28).

Abstract: A cutting head has a resilient male coupling member. The cutting head has a central resilience slit that extends between two major surfaces and opens out to the male coupling member and at least one lateral resilience slit that extends between the two major surfaces and opens out to a base surface. The central resilience slit and the at least one lateral resilience slit each have forwardmost points, located forward of the base surface. Also, a cutting tool that has a tool holder with the cutting head secured thereto. The tool holder has an insert pocket that includes a forward facing holder base abutment surface that has a female coupling member. In a locked position, the male coupling member is resiliently retained in the female coupling member. All points on the male coupling member are under deflection.

Abstract: A cutting tool has a tool shank and a replaceable cutting head resiliently secured to the tool shank by an interference fit between a male fixation member of the cutting head and a female fixation member of the tool shank. The male fixation member has a resilience slit. In each cross section of the cutting tool taken perpendicular to an axis of rotation of the cutting tool through mutual abutment regions, the cross sectional profiles of the mutual abutment regions are arcuate sectors.

Abstract: A drill, such as a spade drill, is provided. The drill includes a drill body that includes a mounting end and a cutting end. The cutting end includes first and second cutting edges that are generally curved along the entirety of the cutting end of the drill body, removing any sort of cutting corner. The curved cutting edge provides a more resilient drill for removing material from a workpiece. The cutting edges may also include a drilling point at a distal end and at least partially between the first and second edges, along with webs extending from the drilling point to the cutting edges. The mounting portion includes structure to attach the drill to a holder, which can connect to a rotating apparatus for rotating the holder and drill.

Abstract: A throw-away rotating tool includes plural protrusions formed in a part of an outer peripheral wall of a projecting coupling portion. Since the twist angle and a twist direction of the protrusions are set in such a way that with relative rotation when coupling the projecting coupling portion and erected portions together, due to the reaction force received by the protrusions from inner peripheral walls, the projecting coupling portion is pulled to the rear and side of the erected portions and the projecting coupling portion is stably held between the erected portions. Since the number of portions that require stringent dimension control and high machining accuracy can be reduced, productivity can be improved.

Abstract: One non-limiting aspect of the present disclosure is directed to a multi-piece twist drill head. The multi-piece twist drill head includes a core piece formed from a first hard material, and a peripheral piece formed from a second hard material. The core piece and peripheral piece each comprise a cutting edge and are adapted to mate to provide a central region and a peripheral region, respectively, of the multi-piece twist drill head. A twist drill including the multi-piece twist drill head is also disclosed.

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: A cutting insert has a head portion and a coupling portion protruding rearwards from the head portion, along a longitudinal insert axis. The head portion has a base surface at a rearward end thereof, defining a base plane, and two major surfaces. A coupling portion rear surface is longitudinally spaced apart from the base surface and a cylindrical coupling peripheral surface extends between the coupling portion rear surface and the base surface. A resilience slit has two opposite inner walls converging forwards towards a slit inner end terminating at a slit inner end plane. The slit inner end plane is parallel to the base plane and spaced apart therefrom by a longitudinal distance. The inner walls of the resilience slit form an acute slit angle therebetween.

Abstract: A cutting tool has a cutting insert secured in a tool shank by means of a clamping bolt, whereby two opposing side surfaces of a body portion of the cutting insert are located between two spaced apart protuberances of the tool shank. The body portion includes a cut-out extending between the two opposing side surfaces and opening out to a bottom surface. The cut-out includes an undercut with at least one undercut sub-surface with respect to a forward direction. The clamping bolt can be rotated from a locked position wherein the bolt shank has a threaded portion engaged in one of the protuberances and a bolt locking portion located directly forward of the at least one undercut sub-surface, to an un-locked position wherein the threaded portion remains engaged in the protuberance and no portion of the bolt shank is located directly forward of the at least one undercut sub-surface.

Abstract: The coupling part, in particular cutting head for a drilling tool for the interchangeable fastening in a coupling receptacle, has a coupling pin which is enclosed by a head support surface, wherein the coupling pin has a plurality of types of functional surfaces, namely stop surfaces for transmitting a torque between the cutting head and the carrier, and clamping surfaces for centering and clamping the cutting head in the coupling receptacle. The coupling pin has an axially front pin region and an adjoining, axially rear pin region, and the clamping surfaces and the stop surfaces are arranged in different pin regions. This decoupling and distribution of the functional surfaces to the various pin regions permits simpler production of the coupling pin and an overall more robust configuration.

Abstract: A tool head includes an ovoid basic element disposed about a center axis, at least two chip grooves formed in the basic element, and a number of major cutting edges. Each major cutting edge is disposed in a convex course along a respective chip groove of the at least two chip grooves. The major cutting edges define with their radially outermost region a nominal diameter. A radial distance from each major cutting edge to the center axis in a front, tip-side, arc portion increases up to the nominal diameter and in a rear, shank-side, arc portion decreases back down to a minimum diameter.

Abstract: A drill, including: a substantially columnar drill holder including, at a front end portion thereof, a first insert pocket and a second insert pocket formed closer to the outer periphery of the drill holder than the first insert pocket; a first insert which is attached to the first insert pocket and includes a first cutting edge at an intersection of an upper face and a side face; and a second insert which is attached to the second insert pocket and includes a second cutting edge at an intersection of a upper face and a side face. The first insert pocket is located passing through a central axis of rotation of the drill holder. The second cutting edge has a concave shape when viewed from the front end side of the drill holder, and has a curved line at least a part thereof.

Abstract: One non-limiting aspect of the present disclosure is directed to a multi-piece spade drill head for a spade drill, wherein the spade drill includes an elongate body portion and a cutting portion removably secured to an end of the body portion. The multi-piece spade drill head includes at least two insert pieces, each piece including a cutting edge. The at least two insert pieces are configured to be removably secured to the body portion of the spade drill adjacent one another and with the cutting edges of the insert pieces aligned to together form a cutting edge on an end of the spade drill.

Abstract: The invention discloses a drilling tool having at least one chip groove for chip removal, having an insert seat which is formed at the end of the chip groove and serves as a holder for an indexable insert with at least one main cutting edge on the two narrow sides and with at least one secondary cutting edge on the two longitudinal sides of one face side wherein the indexable insert has two face sides facing away from one another and bears with its inactive face side on a holding surface of the insert seat, and a partial region of the inactive secondary cutting edge of its active face side lies in the insert seat at a distance from the adjoining side wall of the insert seat created by a slot, and wherein a guide lip which covers the slot protrudes out of the top side of the side wall in the direction of the inactive secondary cutting edge.

Abstract: A tool shank for use with a cutting insert in a rotary cutting tool includes a body having, and adapted to be rotated about, a central longitudinal tool axis, the body having a tip portion structured to receive at least a portion of the cutting insert therein. The shank also includes a pair of chip flutes formed in the body and a pair of recesses, each recess bordering a respective chip flute. Each recess includes a rim portion extending perpendicular to the tool axis and a bearing surface extending at an incline relative to the tool axis. Each rim portion is adapted to engage a corresponding surface on the cutting insert. Each bearing surface is adapted to engage a corresponding bearing surface on the cutting insert in a manner such that the cutting insert is pulled against the body when the rotary cutting tool is rotated about the tool axis.

Abstract: A drill cutting insert has a cutting edge at a transition between a side surface and a top side which is formed with n identical cutting corners and n identical partial cutting edges—with n ? {3, 4}—extending between the cutting corners. Each of the n partial cutting edges has: adjoining a first cutting corner, a main lip which is straight in plan view of the top side; adjoining the other cutting corner, a secondary lip which is straight in plain view of the top side, and a transition section, via which the main lip and the secondary lip merge into one another and which has a convex section adjoining the main lip and a concave section adjoining the secondary lip. The main and secondary lips enclose on the outside an angle ?<180° in plan view of the top side.

Abstract: A drilling tool of the loose top type includes a basic body having two bendable branches having inner support surfaces that are resiliently pressable against side contact surfaces of a replaceable loose top. The mounting of the loose top is affected by turning-in from an initial position to an operative end position. An abutting edge along each side contact surface then bends out the branches and subjects the branches to a spring force that reaches a maximum in a dead position so as to then decrease somewhat up to the operative end position. During the final phase of the rotary motion, the operator obtains, in a tactile and/or auditory way, confirmation of the loose top indeed reaching its operative end position.

Abstract: A loose top for drilling tools, including front and rear ends, a pair of envelope part surfaces concentric with a center axis, and two chip flutes countersunk in relation to the pair of envelope part surfaces between which two bars project radially from a central core, the front end including a cutting edge and at least one clearance surface positioned rotationally behind the cutting edge, the rear end forming an axial contact surface.

Abstract: Embodiments of the invention relate to a reamer for machining a workpiece by chip removal. Embodiments of the reamer can incorporate a holder, having a receiving opening disposed on a workpiece-side end face and having an internal thread, a holder bore extending inside the holder in a longitudinal direction thereof and opening into the receiving opening, an exchangeable head, having a cutting-nose element having a plurality of cutting noses disposed in a distributed manner in a circumferential direction, an exchangeable-head shank having an external thread corresponding to the internal thread disposed in the receiving opening, a bearing contact element disposed between the cutting-nose element and the exchangeable-head shank and having a first bearing contact surface for bearing contact on a first support surface disposed on the workpiece-side end face, with an exchangeable-head bore corresponding to the holder bore extends through the exchangeable head in a longitudinal direction thereof.

Abstract: The invention relates to a cutting tool for a machine tool, comprising a cutting head (1), a shaft (2), and a coupling which removably fixes the cutting head (1) to the shaft (2), said coupling comprising a coupling pin (6) on the back of the cutting head (7) and a receptacle (5) in the shaft (2), which receptacle is complementary to the coupling pin (6) and accommodates the coupling pin (6) when the coupling is closed, comprising a central coolant channel (20) in the shaft (2), which separates into two sub-channels (12) in the region of the receptacle (5), the two sub-channels (12) flanking the receptacle (5) in the wall thereof and opening into the flat contact surface (10) annularly surrounding the opening edge (8) of the receptacle (5), and comprising a flat collar (16) on the back of the cutting head (7) having an annular distribution groove (15). The tool also comprises at least one coolant hole (19) connecting the cutting edges (14) on the cutting head (1) to the distribution groove (15).

Abstract: A step drill bit comprises a body. A cutting edge insert is removably attached to the body. The body may be made of a first material and the cutting edge insert may be made of a second material where the second material is different than the first material. The cutting edge insert may define a plurality of progressively larger cutting diameters.

Abstract: The present disclosure provides a quadrangular indexable drill insert comprising a substantially flat top surface and bottom surface, a side surface adjoining the top and bottom surfaces; four identical cutting edges formed at intersection of side surface and top surface, each cutting edge comprising, a concave curved part edge of predetermined radius at corner of the insert; a first part edge oriented towards axis of drill body and is having negative slope, said first part edge is connected to the concave curved part edge through a nose portion; a second part edge connected to first part edge through a transitional edge, said second part edge is tangentially oriented to an imaginary inscribed circle; a third part edge connected to the second part edge through a transitional edge, and a nose portion of adjoining the third part edge with concave curved part edge of succeeding cutting edge.

Abstract: A cutting insert has a head portion and a coupling portion protruding rearwards from the head portion, along a longitudinal insert axis. The head portion has a base surface at a rearward end thereof, defining a base plane, and two major surfaces. A coupling portion rear surface is longitudinally spaced apart from the base surface and a cylindrical coupling peripheral surface extends between the coupling portion rear surface and the base surface. A resilience slit has two opposite inner walls converging forwards towards a slit inner end terminating at a slit inner end plane. The slit inner end plane is parallel to the base plane and spaced apart therefrom by a longitudinal distance. The inner walls of the resilience slit form an acute slit angle therebetween.

Abstract: The invention relates to a drilling tool with a base, having a central axis of rotation, and a drill bit, detachably connected to the base. The drill bit has a coupling part, which can be coupled with a coupling receptacle on the face of the base and has at least two convexly curved centring portions, which are arranged such that they are distributed over the circumference and engage with an exact fit in complementary concavely curved centring portions of the coupling receptacle. The coupling part has a complementary driver stop, meshing with a rotary driver of the coupling receptacle. It is claimed as novel that the centring portions of the coupling part and/or of the coupling receptacle have clamping surfaces, which run onto each other in the manner of a rotary wedge until the driver stop and the rotary driver come up against each other counter to a predetermined direction of rotation.

Abstract: A fluted drill has a drill body with a fluted drill cutting head removably secured thereto. The cutting head has two drilling portions facing axially opposite directions. In axial view, the cutting head has at least four through openings. Each drilling portion includes a plurality of head flute portions and a plurality of cutting head coupling portions.

Abstract: A cutting tool having a cutting head removably secured to a shank by frictional forces maintained between a male coupling member located in a female coupling member. Support surfaces of the male coupling member engage support walls of the female coupling member. The support surfaces lie on a common cylinder having a larger diameter than a common cylinder on which the support walls lie. The support walls are located on a circumferentially continuous bore wall of the female coupling member.

Abstract: A throw-away rotating tool improves workability of detaching a throw-away tip and prevents from damaging a body. In the throw-away tool, a convex connection for the throw-away tip has protrusions, each of the protrusion includes a sliding contact portion detachably fitted into the inner peripheral groove recessed in the inner peripheral wall of a body. The protrusion has a first tilt portion continuous to the sliding contact portion. In detaching the throw-away tip from the body, the first tilt portion rotates ahead of the sliding contact portion, and a standing portion is elastically deformed due to a wedge effect of the first tilt portion. As a result, the protrusion can be gently removed from the inner peripheral groove.

Abstract: A holder of the present invention has a first insert pocket and a second insert pocket at the tip end thereof. The first insert pocket is located closer to the central axis thereof than the second insert pocket. The axial rake of the first insert pocket is larger than the axial rake of the second insert pocket.

Abstract: A cutting head includes a drill tip having a chisel edge, at least two main cutting edges, each extending between a central end at the chisel edge and an outer end. A recess is associated with each main cutting edge and located at each side of the chisel edge. Each recess includes a chip breaking groove extending along the main cutting edge and spaced from the main cutting edge by a distance. Furthermore, a twist drill has a cutting head and drill tip.

Abstract: A coupling point for a modular rotary which extends in an axial direction. The coupling point includes a first coupling part disposed on a tool head and a second coupling part disposed on a carrier. The coupling parts can be coupled to one another by bidirectional rotation with the formation of an interference fit which acts in the radial direction. Each coupling part includes two coupling faces which lie opposite one another and have contact regions in which the interference fit is formed. In the first coupling part, at least one of the coupling faces has at least two contact regions which are spaced apart from one another in the circumferential direction, and, to this end, at least one first clearance portion is formed between the contact regions, in which clearance portion the two coupling parts do not bear against one another in the coupled state.

Abstract: A drilling tool for machining structural components made of a titanium alloy includes: a support, which extends along an axis of rotation in the axial direction, the support having an end face with a receptacle disposed centrally therein; a plurality of cutting inserts inserted at the end face in a manner that forms a flat drill, each cutting insert having an active insert cutting edge extending transversely to the axial direction; and a drilling tip disposed in the receptacle and having at least two tip cutting edges, the tip cutting edges extending outward from the axis of rotation and being adjoined in each case by at least one active insert cutting edge.

Abstract: An adjustable drill has a drill body having a face surface with a directional feature provided therewith. At least one cartridge is mounted adjacent the face surface and selectively slidable along the directional feature to provide adjustment. At least one insert is releasably affixed in an insert pocket provided in the cartridge. In further examples, the adjustable drill may have a central cutting system in combination with the adjustable cartridge type system, wherein the central cutting system may be modular. There may also be provided a modular type of holder arrangement to provide flexibility to adapt the system for various applications.

Abstract: The present disclosure relates to a quadrangular indexable drill insert. The drill insert includes a substantially flat top surface, a bottom surface and a side surface adjoining the top and bottom surfaces. The side surface comprises four identical cutting edges intersecting the top surface; each cutting edge comprises a first part edge oriented inwardly towards axis of the drill body. A second part edge tangential to an imaginary inscribed circle diameter connected to the first part edge through a convex curve. A third part connected to the second part edge through concave curve and a fourth part edge connected to the third part edge though a convex curve. The insert further includes a curved nose portion at four corners, each adjoining a first part edge of one cutting edge with a fourth part edge of a succeeding cutting edge.

Abstract: A metal cutting tool has a cutting head releasably mounted on a front end of a tool shank, in a self-clamping manner. The tool shank's forward end is provided with a pair of shank coupling portions, each having a forwardly facing shank support surface. A pocket recess is defined between the shank's coupling portions. Within the pocket recess are a plurality of shank fixation surfaces which are parallel to a longitudinal axis of the tool shank. The cutting head has a cap portion and a fixation portion extending in rearward direction therefrom. The cap portion includes a pair of head segments, each having a rearwardly facing head base surface. The cutting head's fixation portion has a plurality of head fixation surfaces which are parallel to a longitudinal axis of the cutting head.

Abstract: A cutting head has a resilient male coupling member. The cutting head has a central resilience slit that extends between two major surfaces and opens out to the male coupling member and at least one lateral resilience slit that extends between the two major surfaces and opens out to a base surface. The central resilience slit and the at least one lateral resilience slit each have forwardmost points, located forward of the base surface. Also, a cutting tool that has a tool holder with the cutting head secured thereto. The tool holder has an insert pocket that includes a forward facing holder base abutment surface that has a female coupling member. In a locked position, the male coupling member is resiliently retained in the female coupling member. All points on the male coupling member are under deflection.

Abstract: A cutting tool has a tool shank and a replaceable cutting head resiliently secured to the tool shank by an interference fit between a male fixation member of the cutting head and a female fixation member of the tool shank. The male fixation member has a resilience slit. In each cross section of the cutting tool taken perpendicular to an axis of rotation of the cutting tool through mutual abutment regions, the cross sectional profiles of the mutual abutment regions are arcuate sectors.

Abstract: An insert includes a body portion and at least one cutting edge disposed on the periphery thereof. The cutting edge includes an inner lip and an outer lip disposed at an angle with respect to one another. A line extending along the inner lip intersects with a line extending along the outer lip at the vertex of the angle. The angular cutting edge further includes a protuberance disposed between, and connecting the inner and outer lips and projecting outwardly away from the body portion beyond the vertex of the angle defined by the intersection of the lines extending from the inner and outer lips. The protuberance having an inner lip connected to the inner lip of the cutting edge and an outer lip connected to the outer lip of the cutting edge to form smooth curvilinear transitions between the lips of the protuberance and the lips of the cutting edge.

Abstract: A cutting insert has the geometry of a tetrahedron with triangle base areas wherein each triangle base area has a tetrahedral frustum as a clamping body for fixing the cutting insert in a tool seat of a carrier tool. Additionally, a tool seat for the cutting insert includes clamping jaws to secure the cutting insert.

Abstract: A single use intramedullary reamer comprised of a reamer head assembly and a reamer shaft. The reamer head assembly further comprising a series of reamer blades that reside in a series of surface slots that are helically oriented around the cylindrical body. The series of reamer blades are bonded with the cylindrical body through induction bonding.

Abstract: A tool for rotary cutting machining includes a tool body and a replaceable cutting head detachably attachable to the tool body. The cutting head has a coupling portion which is receivable in a space between two axially projecting coupling legs of the tool body. Cylindrical internal gripping surfaces are arranged in said space and designed for engagement with corresponding cylindrical external gripping surfaces of the cutting head. The gripping surfaces of the cutting head and the gripping surfaces of the tool body are dimensioned so as to prevent, by engagement with each other, the cutting head from being displaced in axial direction away from the tool body when the cutting head is attached to the tool body. A tool body and a cutting head included in such a tool are also disclosed.

Abstract: Embodiments of the invention relate to a reamer for machining a workpiece by chip removal. Embodiments of the reamer can incorporate a holder, having a receiving opening disposed on a workpiece-side end face and having an internal thread, a holder bore extending inside the holder in a longitudinal direction thereof and opening into the receiving opening, an exchangeable head, having a cutting-nose element having a plurality of cutting noses disposed in a distributed manner in a circumferential direction, an exchangeable-head shank having an external thread corresponding to the internal thread disposed in the receiving opening, a bearing contact element disposed between the cutting-nose element and the exchangeable-head shank and having a first bearing contact surface for bearing contact on a first support surface disposed on the workpiece-side end face, with an exchangeable-head bore corresponding to the holder bore extends through the exchangeable head in a longitudinal direction thereof.

Abstract: A step drill bit includes a shaft for coupling the step drill bit to a drill and a drill bit portion coaxially coupled to the shaft. The drill bit portion has a plurality of step portions. The drill bit portion may further include three cutting edges wherein the cutting edges are spaced around the drill bit in substantially equal arc angles. The step drill bit further includes surface treatment having a first coating formed of first material and a second coating formed of a second material that is applied over the first coating. The step drill bit further includes a replaceable drill bit tip.

Abstract: A drill having a replaceable cutting head, modified to eliminate forces which would distort the pocket of the drill shank and otherwise concentrate stresses which would cause failure of the drill. The cutting head has a frustoconical depending connecting member received in a receptacle formed in the shank. In different embodiments, contact between the pocket formed in the shank and the cutting head connecting member is limited. In one embodiment, angle of drive surfaces is modified from prior art practice. In another embodiment, transition of at curved joints between vertical and horizontal surfaces is made more gradual. The drill preferably has flutes formed collectively by the shank and cutting head when assembled.