Abstract: According to one implementation, an end mill for orbital drilling includes: a shank; a first cutting edge formed in a peripheral portion of the shank; and a second cutting edge formed in a bottom portion of the shank. At least a chamfered edge is formed on a first ridgeline between a first rake face and a first flank of the first cutting edge.

Abstract: A preparation process of a novel drill shank for an IMPACT gun drill, including: manufacturing a mold and a forming block, wherein a forming blind hole is formed in a middle of the mold, the forming block is inserted into the forming blind hole, a wire pipe is disposed in the mold, a feed port is formed in the forming block, a heating cavity is formed in a forming block lateral face and a forming post; manufacturing the forming block with a 2Cr25Ni20 material; injecting tin bronze powder and iron powder into the forming blind hole, starting vibration pressing by the forming block; inputting direct and pulse current to communicate with the metal powder and heat the metal powder at a same time; forming a drill shank blank after 2-3 min, taking out the drill shank blank; removing an adsorbing agent from the drill shank blank by an extraction method.

Abstract: An end-mill comprising a shank and a cutting portion along its longitudinal axis, and formed by combining ceramic and metal based materials via a brazing method. The cutting portion includes a cutting diameter varying between 2 to 20 mm, at least one web thickness found at a blade part, at least one helix angle having a cutting edge thereon, a core diameter that is at least 0.7 times the cutting diameter, at least one corner radius found at the tip part of the blades between the flutes, and axial and radial rake angles at which a cutting operation is made. TiAlN coating is applied over the ceramic-metal based end-mill by a PVD method in order to extend the service life of the end-mill, increase abrasion resistance, and minimize the welding (sticking) problem of chips on the cutting tools.

Abstract: A friction stir welding tool includes a rotation-symmetrical shaft having a proximal end, a distal end, and a pin, which is arranged concentrically about the rotation axis and which has a smaller diameter than the shaft at the proximal end thereof, and thus projects as compared to a shoulder region of the shaft. The shaft, at least in the shoulder region, and the pin each consists of a high-temperature-resistant metal or an alloy thereof. The pin and/or the shaft in the shoulder region consist of or are coated by a composite material, which substantially consists of molybdenum, tungsten, niobium or tantalum or an alloy of at least one of these metals, and a reinforcement phase embedded therein and consisting of at least one material having a Mohs hardness >6, a micrometer particle size, and a free enthalpy of formation at 1300 K of less than ?350 kJ/mol O2.

Abstract: The present invention relates to a tool bit replaceable rotary cutting tool and a rotary cutting method and a tool bit mounting method thereof and belongs to the field of hole machining in the machining industry. At present, a twist drill for drilling is of an integrated structure, and when service life of a tool bit is exhausted, the whole drill is required to be replaced, so that cost is relatively high. For a tool bit replaceable drilling tool, in a drilling process, radial and axial acting forces on a tool bit are relatively strong and thus may cause the conditions of imprecise drilling caused by radial displacement of the tool bit at a joint and the like, a replaceable structure of the tool bit makes the joint of the tool bit of the drilling tool relatively weak and a design of a chip groove makes a substrate of the drilling tool weaker.

Abstract: A cutting tool may include a body, a cutting edge, and a flute. The body may include a rotation axis and extend from a first end to a second end. The cutting edge may be located at the first end. The flute spirally may extend from the cutting edge toward a side of the second end. The cutting edge may include a first cutting edge and a second cutting edge extending from the first cutting edge toward an outer peripheral surface of the body in a front view. The flute may include a first thinning portion located continuously with the first cutting edge at a side of the first end, and a second thinning portion located continuously with the second cutting edge at a side of the first end. A thinning angle of the first thinning portion may be smaller than a thinning angle of the second thinning portion.

Abstract: A modular rotary cutting tool includes a cutting head for insertion into a support. The cutting head has a coupling pin having torque surfaces and clamping surfaces formed on its outer peripheral surface. The coupling pin is divided into a front pin part and a rear pin part. The front pin part is defined by a circumferential groove. Stop surfaces for an axial pullout prevention are formed between the front pin part and the rear pin part. The torque surfaces and the clamping surfaces are arranged in different pin parts. For example, the clamping surfaces are preferably formed on the front pin part and the torque surfaces are preferably formed on the rear pin part. The clamping surfaces taper radially inward in a direction of the front cutting part at an angle of inclination, ?2, with respect to the axis of rotation. Other variants and embodiments are broadly contemplated herein.

Abstract: A drill has a thinning rake face formed in the front end. An intersection ridgeline between the thinning rake face and the tip flank face is the thinning edge. On the opposite side of the rotation direction, the first and second thinning wall surfaces (6b, 6c) and are formed. Viewed from the front, an intersection angle between the thinning edge (4a) and the first thinning ridgeline is larger than 95°. The second thinning ridgeline (L2) is bent to the opposite side of the rotation direction. The thinning edge and the first thinning ridgeline are connected via a concave curve line. The first and second thinning wall surfaces are connected via a concave surface, and a curvature radius of the concave curve line is smaller than a curvature radius of the concave surface.

Abstract: A cutting tool for performing cutting operations on a workpiece when the cutting tool is rotated about a central axis by a machine tool, the cutting tool includes a generally cylindrical body disposed about the central axis. The generally cylindrical body includes a first end and an opposite second end. The cutting tool further includes a cutting portion and a mounting portion. The cutting portion is disposed at or about the first end of the generally cylindrical body and includes a number of cutting edges structured to engage the workpiece during cutting operations. The mounting portion is disposed at or about the opposite second end of the generally cylindrical body and is structured to be coupled to the machine tool. At least a portion of the generally cylindrical body comprises a molded portion formed via a molding process about the cutting portion in a manner that couples the cutting portion to the generally cylindrical body.

Abstract: A method of joining a plurality of parts to form a unitary body. At least two sintered parts are provided. At least one of the sintered parts has at least one internal channel. Each of the parts is formed of a hard metal composition of material. The at least two sintered parts are assembled into the shape of a unitary body. Each of the at least two sintered parts has a joining surface and when each joining surface is brought into contact the surfaces form a bonding interface therebetween. The assembled parts are subjected to a vacuum or gas atmosphere, without the application of external pressure, and to a temperature sufficient to fuse the at least two sintered parts together at the bonding interface to form the unitary body.

Abstract: The drill (1) is provided with a drill body (2) having a rotation center axis (O), two cutting edges (3) provided on the tip side of the drill body (2), and chip evacuation flutes (10) provided behind the two cutting edges (3) in the direction of rotation of the drill (1) from the two cutting edges, the drill tip angle (?) being from 170 to 190°, the web thickness (d) being from 0.10 to 0.25 times the drill diameter (D), the opening angle (?) of the chip evacuation flutes (10) being from 85 to 110°, and the drill (1) comprising a curve having a radius of curvature that gradually decreases from the cutting edge side wall surface (14) to the heel side wall surface (15) of the chip evacuation flutes (10) in a cross-section at a position where the chip evacuation flutes (10) are present.

Abstract: An anti-vibration damper for tools for machining of metallic work pieces is provided. For improving the damping in order to be more effective under rough includes a vibration damping device received in a hollow cylindrical space of a tool member. The vibration damping device includes a plurality of rotationally symmetrical stacked on top of each other to form a stack. A part of mutually facing upper and lower surfaces of adjacent members is spaced at a distance from each other by elastically deformable elements. The outer diameter of the stack is smaller than the inner diameter of the hollow cylindrical space of the tool member, thereby providing a cylindrical gap, which is substantially filled with spherical balls, wherein clear gap width between the inner diameter of the hollow cylindrical space and the common outer diameter of the stack deviates from any integer sum of the ball diameters.

Abstract: In a drill, a negative land is provided on a rake face, and a ridge line at an intersecting position of the negative land and a flank face, a ridge line at an intersecting position of the flank face and a margin, and a ridge line at an intersecting position of the negative land and the margin are convex faces in a longitudinal rectangular cross section. When a curvature radius of the convex face of a first ridge line at the intersecting position of the flank face and the negative land is 1, at curvature radius of the convex face of a second ridge line at the intersecting position of the flank face and the margin is 0.8 to 1.5 times the curvature radius of the first ridge line, and a curvature radius of the convex face of a fourth ridge line at the intersecting position of the negative land and the margin is 1.5 to 3.0 times the curvature radius of the first ridge line.

Abstract: Miniaturized deburring and/or chamfering tool with a cylindrical guide sleeve (2) in which a blade holder base body (5) is arranged in an exchangeable manner, which has at least one receiving slot (20) for receiving and guiding a blade (6) arranged there, which is leaf-shaped and designed so that it can bend along its longitudinal axis, and which, at its free front end, has a cutting head (7) with a deburring or chamfering blade arranged there, wherein an internal cooling of the blade (6) and removal of shavings from the blade (6) are achieved by the fact that the coolant flows around the blade (6) in the receiving slot (20) on at least two facing sides.

Abstract: A method produces a dental drill that has a shank and a work section. The shank contains a centrally arranged, continuous first channel. The work section contains one or more continuous, spiral-shaped further channels. The first channel and the further channels open into a common chamber connecting the shank and the work section. The shank is sintered with the work section in order to form a one-piece, sintered component that encloses the chamber connecting the shank and the work section.

Abstract: A cutting head is formed for insertion into a support in a modular rotary tool, in particular a drill. The coupling head has a coupling having torque surfaces and clamping surfaces on its outer periphery. The coupling pin is divided into a front pin part and a rear pin part. The front pin part is defined by a circumferential groove. Stop surfaces for an axial pullout safety are formed in the transition area between the two the front pin part and the rear pin part. The torque surfaces and the clamping surfaces are arranged in different pin parts. For example, the clamping surfaces are preferably formed on the front pin part and the torque surfaces are preferably formed in the rear pin part.

Abstract: A dental burr and process of manufacture having a synthetic diamond grit abrasive portion. The dental burr includes a dental burr tool substrate including a shaft portion and a working portion. The working portion contains on its outer surface a synthetic diamond abrasive grit cutting surface. The synthetic diamond is brazedly attached to the surface.

Abstract: In the case of a tool holder having a receptacle for a cutting insert, in particular a tangential cutting insert having eight lips, having a lateral bearing surface, a rear bearing surface and a bottom surface, the bottom surface is quadrangular in plan view and has a raised supporting region which has two supporting surfaces, positioned obliquely with respect to one another, for the cutting insert.

Abstract: According to one implementation, a drill that drills at least one of a composite material and a metal is provided. A web thickness at least at a tip of the drill is not less than 5% and less than 25% of at least one diameter of the drill. Further, according to one implementation, a method of manufacturing a drilled product is provided. The drilled product is manufactured by drilling a workpiece using the above-mentioned drill. The workpiece is made of the at least one of the composite material and the metal.

Abstract: A method for manufacturing a part includes metal injection molding of metal powder mixed with a binder to produce individual components of the part as separately molded green compact sections which are then debindered to form brown compact sections. At least one of the brown compact sections is subjected to a pre-sintering process to undergo a first shrinkage. The pre-sintered brown compact section and a further brown compact section are joined together to form a multi-part brown compact which is subsequently subjected to a main sintering process, where the pre-sintered brown compact section undergoes less shrinkage than the further brown compact section to draw together and firmly connect the pre-sintered brown compact section and the further brown compact section.

Abstract: Provided is a drill suitable for high-efficiency working. A cut debris discharge groove is formed in the outer periphery of the drill body front end section rotated about the axis, and a cutting edge is formed at the front end of the drill body. The wall surface of the cut debris discharge groove, which faces the rotational direction of the drill, is formed to have a concave curve line shape in a cross-section perpendicular to the axis, the concave curve line shape extending along a first circular arc.

Abstract: A long twist drill includes a shank and a drill body having a drill tip (16). The twist drill has a length L and an outer diameter D, and has a cemented carbide or high speed steel substrate and a coating of at least one layer. The quota L/D is at least 16. The twist drill has two cutting segments at the tip and two flutes chip. The twist drill is provided with holes for fluid opening in the tip. The twist drill has an axial web thinning angle GAA, which is 40 to 50°. The twist drill further has a web that back tapers such that a web diameter gets smaller in a direction away from the tip towards the shank within an axial distance.

Abstract: A method for manufacturing a wiring board includes preparing a large-sized wiring board having an effective region and a dummy region such that the board has a penetrating hole on a border of the effective and dummy regions and an inner-hole conductive layer covering an inner surface of the penetrating hole, moving a rotary tool having a tip blade along rotation axis at a peripheral portion of the penetrating hole such that the rotary tool drills a hole into the board at the peripheral portion and segments the conductive layer into portions in the effective and dummy regions, and moving a rotary tool having a side blade in a direction perpendicular to rotation axis such that the dummy region is cut off from the effective region after the rotary tool having tip blade makes the hole and a wiring board having the effective region of the board is formed.

Abstract: A cutting tool and cutter body assembly, including a disk-shaped cutter body and a plurality of support pads removably retained therein, the cutter body having an axis of rotation, two opposing end surfaces and a body peripheral surface extending therebetween. Each support pad intersects one of two annular-shaped planes equidistantly offset from opposite sides of a median plane perpendicular to the axis of rotation, and the cutter body intersects neither of the two annular-shaped planes. Each support pad is configured to make operative contact with a machined surface of a workpiece perpendicular to the axis of rotation. Each support pad has opposing upper and lower surfaces and a pad peripheral surface extending therebetween, the pad peripheral surface having an upper portion intersecting the upper surface, and the upper portion exhibiting N-fold rotational symmetry about a pad axis non-perpendicular to the lower surface.

Abstract: Composite compositions and machine and contact tools, for example, metal boring tools and face mills that are manufactured from them. The tools are provided with composite structure to lighten the tools and yet retain the strength and durability of the tool. The novelty resides in the use of additives to certain composites that make up a portion of the tool, especially tool bars.

Abstract: A drill main body of an indexable drill is disposed first and second spiral flutes on a column-shaped outer circumferential surface with an inner blade tip cutting a hole center side mounted on a tip portion of the first spiral flute and an outer blade tip cutting a hole outer circumferential side mounted on a tip portion of the second spiral flute and the drill main body discharges chips through the first spiral flute and the second spiral flute toward a shank while hole machining is performed with the inner blade tip and the outer blade tip. The drill is a deep hole machining drill having a length of the first spiral flute and the second spiral flute equal to or greater than 4D relative to a drill diameter D that is an outer diameter of the outer blade tip.

Abstract: A bit exchangeable drill includes a detachable cutting head at the tip of a drill body, and the cutting head includes a cutting edge extending linearly from a rotation center to a radial outer end in axial end view, and a helical flute. At a rake face continuous with the cutting edge, a thinning face inclined relative to the rotation axis and rendering an axial rake angle of the cutting edge negative is formed entirely from a radial inner end to a radial outer end of the cutting edge.

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: Rotatable drilling tool has an insert top detachably connectable to a basic body and at least one chip flute. In each cross-section, each chip flute has a depth equal to the difference between the radius of a cutting circle and a radius of a greatest possible core circle centered on the longitudinal axis and tangential to a limiting curve of the respective chip flute. The basic body is divided longitudinally into a coupling segment, extending axially rearward from a coupling end, and a transportation segment that is situated axially behind the coupling segment, extends rearward toward a fixing end, and is longer than the coupling segment. Each chip flute extends through the coupling segment and the transportation segment. At least essentially the entire female part is situated in the coupling segment, and each chip flute has a smaller depth in the coupling segment than in the transportation segment.

Abstract: A multi-flute reamer includes a cutting portion having a forward end and a rearward end, and a chip flute with a chip gash opening, and a cutting insert mounted on the cutting portion. A leading edge is formed at an intersection between a top surface and a radially-outward side surface, and a front edge is formed at an intersection between the top surface and a forward side surface. The cutting insert includes a rounded lead cutting edge formed at the intersection between the leading edge and the front edge, and the top surface includes a chip breaker having a bottom surface formed with a radius, R.

Abstract: A drill includes a drill bit, an intermediate part, and a shaft. The drill bit is made from a sintered carbon-containing hard metal. The intermediate part is made from steel and arranged along an axis between the drill bit and the shaft. An activity of carbon in the steel of the intermediate part is greater at a temperature ranging from 1100° C. to 1450° C. than an activity of carbon in the sintered hard metal at the temperature.

Abstract: A rotary tool extends in the direction of an axis of rotation and includes a carrier having a coupling receptacle disposed at an end face, the carrier having a carrier cross section. The coupling receptacle is delimited in the entire region of the carrier cross section by an outer web having an end face forming a planar bearing area. The coupling receptacle is delimited by side walls which extend step-free from the bearing area to a bottom area and include a pair of opposing clamping segments extending in the circumferential direction and a pair of opposing torque segments arranged at an angle thereto. The tool also includes a cutting head exchangeably fastened to the carrier, the cutting head having a coupling pin disposed in the coupling receptacle. At least one of the pairs of segments is oriented inclined in relation to the axis of rotation.

Abstract: The invention relates to a multi-blade solid carbide drill for cutting high-strength sandwich materials. The tool comprises a shaft section and an adjoining cutting part, into which a number of chip flutes that corresponds to the number of main blades is incorporated. In order to reinforce the curvature of the resulting chip, the chip flute of the drill comprises a chip flute rib in the region of the chip formation zone, said rib protruding from the chip flute surface and having a substantially wave-shaped cross-section (28), and said rib dividing the chip flute into two sections, a first chip flute section (30) forming the cutting rake and a second chip flute (32) forming the chip flute runout.

Abstract: A reconfigurable cutting tool includes a boring head at one end, an attachment portion at a second end that is opposite the first end, and a boring bar disposed between the boring head and the attachment portion. The boring bar is made of a shape memory material such that a geometry of the reconfigurable boring tool is selectively changed in response to an activation signal from a temperature controlling processor.

Abstract: A handheld surgical device includes a multi-position throttle, rotatably attached to the body of the device, to allow for ambidextrous positioning of a motor speed control lever. The motor speed control lever may interact with a speed control sensor in the body of the device capable of detecting the actuation level of the motor speed control lever in any one of two or more positions.

Abstract: A screw tap includes a shaft having at least one cutting portion and a drive portion. The drive portion is of a cross-section complimentary to tools adapted to act upon the drive portion. The shaft is provided with a recess extending axially thereof and adapted to receive drive device having a cross-section corresponding to the cross-section of the recess.

Abstract: In order to allow high-precision machining of the inner surface of a pipe using little machining time, the draw broach has a cutting part having a plurality of cutters extending in the axial draw direction. The cutting part is divided into a main part and an insertion part tapering conically in the draw direction. The insertion part in turn is divided into a front region, viewed in the draw direction, forming a pre-cutting stage, and a rear region, wherein the conicity of the pre-cutting stage is less than that of the rear region.

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: An elongated drill bit has a shank at one end and working end at the other. A flute portion is between the working end and the shank. The flute portion is continuous with the shank and working end and is generally unitarily formed with them. The flute portion has at least one flute with a helix angle between approximately 30° and 35°. The working end has a pilot tip with a cutting portion. A tapered web is formed in the flute portion, a thickness of the web at the tip of the working end is about 9% to 15% of the nominal diameter.

Abstract: A cutting tool for performing hole-cutting operations on a workpiece when the cutting tool is rotated about a central longitudinal axis includes a generally cylindrical body having a first end structured to be mounted to a machine tool and an opposite second end structured to engage and perform cutting operations on the workpiece. A number of coolant passages are defined in the generally cylindrical body, each coolant passage of the number of coolant passages is disposed at a first helix angle relative to the central longitudinal axis. A number of flutes are formed in the generally cylindrical body, each flute of the number of flutes includes a first portion at or about the first end of the generally cylindrical body, a second portion at or about the second end of the generally cylindrical body, and a transition portion disposed therebetween.

Abstract: A bi-metal drill bit includes a body defining a cutting end and a shank end. At least a portion of the cutting end is formed of a first metal section and at least a portion of the shank end is formed of a second metal section that is welded to the first metal section. The first metal section has a first metal having a material hardness that is higher than a second material hardness of the second metal section. One of the first and second metal sections is treated either by coating or oxide treating so as to have a recognizable different appearance than the other of the first and second metal sections. A length to diameter ratio of the first metal section has been optimized to allow electrical resistance welding, provide better strength in the rear end after the tip breaks through a workpiece, and to minimize cost.

Abstract: Composite articles, including composite rotary cutting tools and composite rotary cutting tool blanks, and methods of making the articles are disclosed. The composite article includes an elongate portion. The elongate portion includes a first region composed of a first cemented carbide, and a second region autogenously bonded to the first region and composed of a second cemented carbide. At least one of the first cemented carbide and the second cemented carbide is a hybrid cemented carbide that includes a cemented carbide dispersed phase and a cemented carbide continuous phase. At least one of the cemented carbide dispersed phase and the cemented carbide continuous phase includes at least 0.5 percent by weight of cubic carbide based on the weight of the phase including the cubic carbide.

Abstract: A bevel head replaceable rotary tool is provided. The rotary tool includes a coupling protrusion and a coupling recess, plural sets of serrations provided on an outer circumferential surface of the coupling protrusion and an inner wall surface of the coupling recess, circumferential abutting portions provided on the tool body and the bevel head, and axial tight-contact portions, provided on the tool body and the bevel head. The serrations of the coupling protrusion and the serrations of the coupling recess arranged such that curvatures of circumferential circular arcs of the serrations of the coupling protrusion are greater than those of the serrations of the coupling recess or the serrations of the coupling protrusion and the serrations of the coupling recess have circumferential circular arcs with centers deviated from each other.

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 method of fabricating a micro drill, which includes a drill part for machining a hole and a shank part fixed to a motor, the drill part and the shank part being made of different materials. The method includes the steps of forming a drill part-forming powder compact having a recess in one end thereof, and forming a shank part-forming powder compact having a protrusion, the protrusion intended to be fitted into the recess of the drill part-forming powder compact, forming an assembly of the drill part-forming powder compact and the shank part-forming powder compact, with the protrusion fitted into the recess, and simultaneously sintering the assembly of the drill part-forming powder compact and the shank part-forming powder compact.

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 present invention relates to a method for coating a substrate, preferably a drill, wherein at least one first HiPIMS layer is applied by means of a HiPIMS process. Preferably, at least one second layer is applied to the first HiPIMS layer by means of a coating process that does not contain a HiPIMS process.

Abstract: The tool has a clamping part (2) and a working part (11). It consists of a wear-resistant material, which contains tungsten carbide which has a grain size that lies in the range between approximately 0.2 and approximately 0.5 ?m. The clamping part (2) consists of a tough material, which likewise contains tungsten carbide which has a grain size in the range between approximately 0.8 and approximately 1.3 ?m. In a transitional region (11) between the working part (11) and the clamping part (2), the proportion of wear-resistant tungsten carbide decreases in the direction of the clamping part (2) to 0 and the proportion of tough tungsten carbide decreases in the direction of the working part (11) to 0. The mixing ratio between wear-resistant and tough tungsten carbide changes approximately steadily in the transitional region (10).

Abstract: A drill having a drill head (11) made of hard metal and a shaft (12) or a coupling piece (16) made of a sintered iron alloy. The hard metal is joined in the form of a material connection to the sintered iron alloy by a sintering process.

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.