Abstract: A drilling tool includes a drill body having axially spaced front and rear ends. The front end includes tangential pockets for carrying cutting inserts spaced by respective radial distances from a center axis of rotation of the drill body. Two chip canals are formed in the front end surface adjacent respective pockets for conducting away chips. The canals are interconnected by a chip space located rearwardly of the front surface, to form in the drill body a bridge which extends diametrically and carries a plurality of the pockets. Each insert pocket includes an axially extending abutment surface against which a rear wall of a respective insert engages. Each of the abutment surfaces and rear walls is of semi-circular shape.

Abstract: The present invention provides a method and apparatus for forming a plurality of parts, such as spade-type boring bits, from a continuous stock material. Thus, the various steps of the forming method of the present invention can be performed to predetermined portions of the continuous stock material, prior to separating the continuous stock material into a number of discrete parts. The efficiency of the forming process is enhanced since individual parts need not be individually transported and oriented during the forming operations. By not requiring that the individual parts be separately transported and oriented during the forming operations, the quality of the parts formed by the forming method and apparatus of the present invention will also be enhanced since such separate transportation and orientation of individual parts generally increases the opportunities for misalignment and contributes to poor tolerance control during the manufacturing process.

Abstract: A drilling tool for drilling in metals has in its front part cutting insert-carrying cartridges, for instance 3, 5 or 7 in number. The peripheral cartridge (6) carries a peripheral cutting insert (7). This peripheral cartridge is fastened in the drill by a locking screw (16) that extends in a slot (17) in the drillhead. Radially inside of the peripheral cartridge is a wedge (15) which can be displaced axially and thereby regulate the radial position of the peripheral cartridge and cutting insert and, thereby, the cutting diameter. When the desired radial adjustment has been attained, the peripheral cutting insert is fixed by the locking screw (16). In this way, a very exact adjustment of the cutting diameter is obtained.

Abstract: A cutting tool for forming complex ports within metal workpieces. The present invention provides a cylindrical body to one end of which are attached indexable cutting inserts. One set of inserts is provided at a reduced diameter portion of the shaft for forming a boring section which enlarges and uniformly shapes the diameter of a pilot hole. A second set of inserts is provided at an enlarged diameter section of the shaft for performing multiple functions such as forming both the countersink and the spot face areas of the port. Each set of cutting inserts is substantially equidistantly disposed about the circumference of the shaft to reduce the chatter or deflection of the porting tool and therefore allow a port to be formed in adherence with very tight tolerances. In addition, since at least two inserts are provided at each diameter, the axial feed rate of the porting tool is relatively high in that a full revolution of the tool is not required to form a cut as is required by prior art porting tools.

Abstract: A center drill used for machining a hole in a work piece which is adapted to be partially enclosed in a cup shape drill member in a side view thereof, includes a drill portion provided on a leading end of the center drill, and a dust extractor radially outwardly extending from a portion of the center drill which is enclosed in the cup shape drill member.

Abstract: A wood drill with a point, cutting lips at the point, a shank and a body. The body having lands defining between them flutes. The flutes have a high helix reach extending from a distance from the cutting lips toward the shank, an intermediate helix reach extending from the high helix reach toward the shank and a low helix reach extending between the intermediate reach and the shank. The drill has screw threads in a peripheral surface of the lands from a point adjacent the cutting lips a distance toward the shank less than the length of the high helix reach of the flutes.

Abstract: An improved hole saw for cutting holes having a cylindrical shape that includes, along its cutting edge, a plurality of repetitive groups of saw teeth having at least four radially displaced trailing teeth. The displacement of each trailing tooth is such that it has a substantially greater displacement than for any other tooth of said group preceding said trailing tooth. The displacement of each tooth being such that the cutting edge thereof is characterized as being movable along a cutting path different from the cutting paths of the other teeth of the group as the hole saw is rotated whereby each tooth cuts chips of uniform size. Each group of teeth may include a raker tooth having no substantial displacement with respect to the side surfaces of the hole saw. The raker tooth may be the same height or of greater height than the trailing teeth.

Abstract: A tool assembly comprises first and second tool assembly units formed with interfitting male and female coupling members coaxially coupled together so as to have a common longitudinal axis, whereby a moment transmitted to the first unit is transmitted to the second unit. Each coupling member comprises a torque transmitting component having a central portion of a radial dimension defined by a radius of a circle inscribed therein and at least one arm extending from the central portion to periphery of the corresponding coupling member. The arms of the male and female coupling members have first side walls along which the coupling members generally contact and second side walls having a gap therebetween. The first walls are directed, at least at their contact regions, substantially radially with respect to the longitudinal axis.

Abstract: The invention pertains to a drilling tool for drilling in solid metal. It comprises a base body with flutes for chip removal and two interchangeable inserts (1) designed especially as reset bits, having the same shape and size and being arranged in a recess at the end of a flute at the front of the base body. The inserts (1) are situated at different radial distances from the drilling tool axis (30) with overlapping work ranges. The blade (4,4a) of the insert (1) is formed by two cutting edges (10, 10a) and (14, 14a) which together form an obtuse point angle (18). The insert (1) is characterized by an extended form in its longitudinal direction L with channel-like troughing of its faces (3) running essentially in the longitudinal direction and by an arrangement of the blades (4,4a) at the channel ends. Furthermore, the channel has a base surface (9) which with its longer parallelogram sides (6,7) forms an acute angle (8) with the longitudinal axis (2) of the insert (1).

Abstract: An expansible drill is provided for drilling and undercutting holes. The drill comprises a rotatable tubular drill body having a drill head at one end for cutting a bore. At least one undercutting arm is located within a slot in the drill body and attached by a hinge such that at least a part of the arm is pivotal radially outwards. A guide is provided for moving the arm radially outwards, the guide comprising a shaft which is located within the drill body and constrained to rotate therewith. A locking mechanism selectively prevents or allows the shaft to move axially relative to the drill body as force is applied to an end of the shaft.

Abstract: A reamer for precision machining of holes includes a reamer body and a knife plate supported above the exterior of the body and extending along the exterior. The knife plate has a front lower radial height cutting region and a rear taller radial height cutting region joined by an inclined step so that the first front region does the major cutting and the second rearward region does the finer machining. The front cutting region has an entrance bevel. The inclined flank shapes of the cutting regions are disclosed. Reamer guide strips supported along the support have a similarly shaped bevel and step as the knife plate.

Abstract: A drilling tool having a cylindrical body with a central axis. A first cutting insert with a cutting edge extending from a datum plane from a position about half way between the central axis and the outer edge of the holes and extending toward the first end of the tool at a first acute angle and a second cutting insert extending from the datum plane extending generally outwardly at a second acute angle substantially less than the first acute angle so that the cutting path of the second insert intersects the cutting path of the first insert whereby four chips are cut by the cutting tool.

Abstract: A drilling tool for rotary percussion drilling including: a drilling body defining: a longitudinal centerline axis extending in a drilling direction; a bore extending in a direction of the centerline axis and having a bore bottom; and a recess extending in a direction transverse to the centerline axis and eccentrically with respect thereto. A centering drill is adapted to move in the drilling direction and has a centering drill end, a centering drill shank and a chucking portion having a flattened clearance on one side thereof, the centering drill shank having an end side cylinder section for limiting an axial path of the centering drill during its movement in the drilling direction, the centering drill extending in the bore of the drilling body and the bore bottom being effective as an exclusive stop for the centering drill end when the centering drill is being subjected to percussion stress.

Abstract: A percussive blow assisted rotary drill includes an axially extending shank (1) with a leading end face (3) and an axially extending outside surface (2) containing a helically extending drilled material removal groove (4, 5). At least one hard metal cutting plate (6) extends across a diameter of the shank and has a base part fixed in a continuous groove (9) in the leading end face (3) of the shank (1). The base part (10) is reinforced by an outwardly extending projection (12) in at least one of its side surfaces extending across the shank diameter. Preferably, the projections forms a part of a circle and are centered between the opposite ends of the cutting plate. The continuous groove (9) has a recess in at least one of its side surfaces shaped to coincide with the shape of the outward projection (12) on the cutting plate. Accordingly, the base part (10) is secured in a positively locked manner and preferably is centered in the leading end face of the shank.

Abstract: A self-centering indexable drill having cutting inserts disposed such that cutting forces on the inboard and outboard flutes of the drill body are substantially equal while boring a hole, thereby keeping the drill body substantially centered. The drill includes a drill body and a plurality of cutting inserts. The drill body includes a shank portion configured to be received by the spindle of a machine using the drill, a collar, and a fluted portion. The fluted portion of the drill body defines an inboard flute and an outboard flute. At least one cutting insert is releasably secured to each of the inboard and outboard flutes, with an equal number of cutting inserts carried by each. An insert pocket is defined by the drill for closely receiving each cutting insert such that the leading face of the cutting insert is substantially flush with the face of the flute.

Abstract: A tool bit for use in at least one of a drilling and cutting operation is formed of an axially extending carrier member (1) and a cutting member (2). The cutting member (2) has an expansion joint (2a) extending parallel to the axis of the carrier member (1). The expansion joint (2a) is formed by reducing the thickness of the cutting member (2) so that material webs (2b) remain. In the fabrication and formation of the tool bit, the cutting member (2) is a single unit. In the use of the tool bit, due to the expansion joint the cutting member forms individual operating units (2a) affording reduced material expense of the cutting member (2), because of reduced stresses.

Abstract: An improved self centering spade drill having at least three cutting blades extending radially outward from the center of the drill, the front edge of the blade constituting the cutting portion of the drill, the rear edge of the blade constituting the port end of the drill which are adapted to be received and supported by a drill holder.

Abstract: Reamers, when operated with large amounts of material removed and at high reaming speeds, encounter difficulties when they ream in material in which permanent structural changes occur on the application of heat and subsequent rapid cooling. These difficulties are avoided in that the transition region between the main cutting edge and the minor cutting edge follows a constantly curved path at least one end region of which runs tangentially to at least the minor cutting edge.

Abstract: A diamond coated elongate rotary cutting member and method of making the same. The cutting member includes an axially forward cutting surface, a flute and a fluted land. The cutting member comprises a substrate with hard grains bonded together with a metallic binder. The substrate has a first substrate region that presents an irregular surface so as to define the axially forward cutting surface and the fluted land. The first substrate region contains relatively large hard grains near the surface thereof that are larger in size than the hard grains in the interior of the substrate. A diamond coating is on the surface of the first substrate region. The substrate has a second substrate region that defines the flute.

Abstract: Cutting elements or cutter chips (7, 8) are located on a tool body (1). Cutting chip removal spaces (14, 15) are formed in the tool body in three segments. A first segment (I) adjoins the end face (4) of the drill body and includes at least one cutting element seat (10, 11); a chip removal space extends axially, i.e. straight, or slightly obliquely fluted. A second segment (II), adjacent thereto, is formed partially helically with a twist (21) of less than 90.degree. relative to the tool body axis; the second segment (II) terminates axially at a point where, in operation, the direction of radially acting cutting forces coincides essentially with the primary axis of inertia (0-0) of the geometrical moment of inertia. A third segment (III) adjoins the second segment (II); it is essentially straight-fluted.

Abstract: A drilling tool having an elongated body with a longitudinal axis and provided with at least one insert receiving pocket and an indexable cutting insert for use with the drilling tool for performing drilling action is disclosed. The insert of the drilling tool includes a rake face, relief flank faces, a base, a plurality of cutting edges, each defined between the rake face and adjacent relief flank face and included between two adjacent cutting corners. Each cutting edge has at least one set of component cutting edges, each set having two pairs of component cutting edges merging in a common point, each pair comprising a first and a second component cutting edge merging via a bridging section directed towards a central line constituting or parallel to a median line of the insert and passing through the common point.

Abstract: A drill comprising a holding section, a prismal section receivable by the holding section, and a top-truncated, pyramidal section which is integral with the prismal section, with the prismal section having side faces and side ridges defined by the adjoining two side faces, the top-truncated, pyramidal section having end faces which taper and coverage on the axis of rotation of the drill, end ridges which are defined by meeting of the adjoining two end faces, and a truncated surface extending across the axis of rotation and forming an angle of more than 1.degree. to less than 90.degree. with the cross-section of the prismal section. The end faces and end ridges of the pyramidal section extend from said side faces and side ridges of the prismal section, respectively. Because the apex of the drill is located out of the axis of rotation, it has enhanced cutting performance.

Abstract: A novel surgical router bit is disclosed which comprises a shaft having a distal end and a proximal end and an outer surface tapering outwardly from its distal end to its proximal end, at least one spiral cutting flute or groove formed in and extending along the length of the shaft from the distal end of the shaft to the proximal end of the shaft, with the at least one spiral cutting flute or groove having a planar floor which is inclined relative to the center axis of the router bit, wherein for each pitch of the at least one spiral cutting flute or groove, the distal end of the floor is level with the tapering outer surface of the shaft and the proximal end of the floor has a fixed depth relative to the tapering outer surface of the shaft so as to define a helical cutting edge of fixed height, and at least one straight cutting flute or groove formed in and extending along the length of the shaft from the distal end of the shaft to the proximal end of the shaft, the at least one straight cutting flute or gro

Abstract: A hand-held drilling tool has at least one but preferably two blade structures which project longitudinally from a transverse base member to terminate in a distal end that forms a cutting element. Each blade structure has a pair of blade sections that are joined together along the longitudinal axis and that extend radially therefrom to terminate in lateral edges. Where two blade structures are present, each forms a handle for rotatably operating the other blade structure; where only one blade structure is present, a flattened handle is provided. The blade structures can have different blade widths for drilling differently sized holes. The blade sections may be offset from one another, and wedge-shaped feet may be disposed on the cutting elements. One of the blade structures can have both a bit portion and a shank portion of different widths. A pilot tip may also be provided on the distal ends of the blade structures. The drilling tool is configured for unitary molding from a plastic material.

Abstract: A primer pocket reamer for cartridge cases makes three distinct cuts for removing stake rings, chamfering the outer edge of a primer pocket and endmilling the bottom in a single process. This is accomplished by a cutter with three different rotating cutting edges. The cartridge case is brought to the cutter.

Abstract: A drill for fiber-filled synthetic plastics has an axially extending body with helical grooves spiraling from a drill point toward a shank end. The grooves define helical lands between them having helical land machining edges. At the point axially tapering land and groove point surfaces converge and land point surfaces with machining edges are radiused to merge gradually with the land surfaces rearward of them. The land machining edges are configured with a negative rake. A plurality of cross notches on the lands extending over an axially extending region of the lands from substantially the axially tapering land point surfaces a predetermined distance toward the shank end are configured to create fiber-snipping crosswise helical cutting edges with a positive rake facing the point.

Abstract: A spiral drill and a method to manufacture a spiral drill with two indexable inserts at different distances from the center line and two coolant channels, where the coolant channels (23,24) run parallel to the center line within the shank part, and where the spiral part has been twisted while heated to form spirally curved coolant channels (17,18), and where exit channels at the tip have been drilled after twisting, and where the exit openings (21,2) are located at different distances from the center line.

Abstract: A drill for drilling in metal with improved performance in the smaller diameter range. The drill comprises a drill shaft, the front end of which is provided with radially outer and radially inner inserts, each insert having elongated rhomboidic shape, in which each of the short sides is broken at its middle to form a V-shape having an internal obtuse angle. The inserts are arranged such that the longitudinal axis of the radially outer insert is inclined at an angle from the longitudinal axis that is different from the angle of inclination between the longitudinal axis of the radially inner insert and the longitudinal axis of the drill.

Abstract: A threaded hole may be formed in a lid of an underground petrol tank without emptying the tank or removing the lid, using a tool (FIG. 3) having a taper tap section (61), an intermediate tap section (62) and a final tap section (63). At the leading end of the tool, there is a reamer section (60) and supported on the free end of the tool is a centerless hole cutter (50). A resilient mounting transmits drive from the main part of the tool to the cutter (50), but allows the cutter to float. A sleeve (23) surrounds the tool, so that a column of inert gas may be caused to lie in the cutting region. A magnet (57) mounted within the cutter (50) catches and holds a released disk of the cover. Also described is a rig (FIG. 1), for operating the tool (FIG. 3), and a method (FIG. 5) of securing a collar threaded into a hole formed by the tool.

Abstract: A combination tool has a tool holding fixture for connecting the combination tool to a drive spindle of a machine tool. The tool holding fixture includes a receiving member. A grip with tensioning sleeve is provided. The grip is received in the receiving member of the tool holding fixture and clamped with the tensioning sleeve within the receiving member. The grip has a receiving element for receiving a shank of a working tool and an end face facing away from the holding fixture. At least one cutting member is connected to the end face of the grip.

Abstract: It is an object of the invention to provide an economical milling cutter for T shaped groove.This invention is a milling cutter for T shaped groove comprising at least three cutting edge mounting seats distributed peripherally on a body one end flange of the milling cutter, on the first cutting edge mounting seat a first cutting edge for cutting remotest part from the cutting machine being mounted, on the second cutting edge mounting seat a second cutting edge for cutting nearest part from the cutting machine being mounted, on the third cutting edge mounting seat located between the first and second seats a third round or polygonal cutting edge being mounted, and the third cutting edge projecting radially outwardly from the rotation center line of the body between and from two portions cut by the first and second cutting edges.

Abstract: A twist-bladed dental drill with an enhanced cutting tip for preparing surgical sites for endosseous implants includes a central, axially-extending internal passageway for carrying fluid through the shank of the drill to the outer surfaces of the drill.

Abstract: A high performance cutting tool for drilling complex holes in a work piece comprising a body having a shank for rotating the tool with a drilling machine, an intermediate flute portion having a plurality of straight flutes formed thereon, and a forward, nose portion. A unitary insert having a plurality of cutting edges formed thereon is received in a slot formed in the cutter tool so as to be driven thereby in a manner which permits cutting of a complex hole in a work piece when the cutting tool is rotated in the work piece.

Abstract: A center tool with a shank receivable in a sleeve carried by a body of a holder which may have cutters on a work surface disposed outward of the sleeve. A hydraulic actuator forces the sleeve radially inward to grip, releasably retain and center the shank of the center tool to permit rapid removal and replacement of the center tool. The actuation may also react radially outwardly to move the body and cutters radially outward to vary and adjust the diameter of the bore machined by the cutters on work surfaces. Preferably, the tool holder has a shank received in a chuck with the holder or chuck having a hydraulically actuated sleeve to retain the tool holder in the chuck.

Abstract: A drill having at least one and generally at least two cutting inserts fixed in a cutting end of the drill and in which each cutting insert is a polygonal body having at least three cutting vertices and respective cutting edges between the vertices which are set back so that cutting points are formed close to a vertex. The partial cutting edges formed by the setback extend rectilinearly to the cutting points and include an angle of up to 170.degree. between them.

Abstract: The present invention is a drill screw including a shank having a head at one end, a drill bit at the other end and a threaded section therebetween. The threaded section and the drill bit are operatively adapted such that drilling with the bit is performed by torquing the shank in a rotational direction opposite to that used to screw the threaded section into a bore hole.

Abstract: A boring tool having a tool body (10) which has a pair of chip discharge flutes (11) formed in the peripheral surface thereof. A cutting edge (13) is formed on the edge line where the end relief surface of the tool body intersects the wall surface of each chip discharge flute which faces forwardly as viewed in the direction of the tool rotation. A first margin (15) is provided on the end of the land which is on the trailing side of the flute (11) as viewed in the tool rotation direction, while a second margin (17) is provided on the end of the land adjacent to the heel (16). The lands are provided with recesses (20) in the depths of each of which progressively increase from the first margin towards the second margin. A sub cutting edge (21) is formed on the edge line where the end relief surface meets the wall surface of the recess (20) which faces forwardly as viewed in the direction of the tool rotation.

Abstract: A drill and countersink tool having a drill bit member fixedly attached to a mounting member. The mounting member has exterior threads by which it is ajustably mounted in a countersink member in a manner that the drill bit extends downwardly from the countersink member. A lock nut is threaded onto the mounting member to come into locking engagement with the countersink member. By loosingly the lock nut, the position of the drill bit and the mounting member can be adjusted for different drill lengths.

Abstract: A power drill bit having a stepped construction, referred to as a cone drill, and a quick change capability provided by a shank having a non-circular cross-section and a circumferential groove for quick connect-disconnect in a power tool or drill. The preferred embodiment includes a hexagonal shank which is at least one-half of the axial length of the drill bit in order to provide a better engagement to the power chuck.

Abstract: A cutter shell for cutting a circular opening in a metal object formed of a tubular boring portion and a head portion. The boring portion has a tubular sidewall and teeth at the forward circumferential end. The sidewall is of thickness not greater than the teeth. The head portion has an outer circumferential perimeter secured to the tubular portion rearward circumferential end, the head portion being attachable to a boring bar by which the cutter shell is rotated. A circumferential abrasive band is affixed to the exterior circumferential surface of the tubular sidewall for engagement with the wall of a hole as the hole is cut in an object by the teeth to smooth and round out the hole for improved cylindricality.

Abstract: A twist drill having a longitudinal axis, a shank portion sized and shaped to be grasped by a twisting tool, and a barrel portion for cutting a workpiece. The barrel portion has a number of flutes formed therein spiraling about the axis and terminating at a point end of the barrel portion. The point end has a number of point surfaces including an inner flank surface, an outer flank surface, a groove surface positioned between the inner and outer flank surfaces and a split surface. The inner flank surface extends from the center of the point end to the inner extent of the groove surface and the outer flank surface extends from the outer diameter of the point end to the outer extent of the groove surface.

Abstract: A tool provided with a head tapering stepwise toward a front side. Each step of the head has a cylindrical area for calibrating a pipe end and, joining it, a conical area for deburring the pipe end. Each step of the head corresponds to a usual pipe size. When the head is pushed into a pipe end to be processed, the pipe end is first calibrated and subsequently deburred in one operation. The pipe end is centered in relation to the longitudinal axis of the head due to the calibration at the cylindrical area, which guarantees accurate deburring at the conical area. Each conical area has a plurality of cutting edges, which are formed by chip grooves. The tool is especially suitable for preparing pressed connections on composite pipes.

Abstract: Burrs formed at the ends of a bore during a honing operation performed by a single pass honing tool are removed by a deburring attachment which is carried on the leading end of the tool. The attachment includes one set of spring-loaded blades which remove burrs at one end of the bore as the tool is retracted from the bore and further includes an axially spaced set of spring-loaded blades which remove burrs at the opposite end of the bore during retraction of the tool.

Abstract: A portable, hand-held bevelling device for providing a bevel on both the exterior and an interior of a tube comprises a housing having an interior and an upper extended portion and a lower extended portion. The upper extended portion is spaced a distance away from the lower extended portion for defining a space. A hydraulic clamp is located on the exterior of the housing and comprises an upper clamp portion provided on the upper extended portion of the housing and a lower clamp portion provided on the lower extended portion of the housing for hydraulically clamping a tube. A bevelling head having cutters for providing the interior and external bevels on the tube is contained within the interior of the housing and is extendable through the space between the upper extended portion and the lower extended portion toward the exterior clamp. The bevelling head is connected to a movable shaft located within the housing wherein both the head and the shaft are rotated by an air motor and a drive belt.

Abstract: A diamond coated drill bit capable of drilling small holes and then reaming the holes to their correct size. The tapered tip of the drill bit has a coarse diamond grit coating which enables it to initiate a hole. The drill bit then gradually grinds the hole to the proper size with a grinder having coarse diamond grit bonded to its surface which is at a predetermined taper. The final diameter of the hole is controlled by using a fine grit diamond reamer above the tapered grinder portion. The grinder applies a radial load to the composite material resulting in no fiber breakout or splintering. The tapered grinder and the reamer are formed on a machined-flat portion of the drill bit which enables coolant to circulate down to the grinding area and allows the easy removal of debris.

Abstract: A drill with indexable inserts has one center insert (11) and one peripheral insert (12), said center insert having a symmetric drill point (25) on the drill axis (10) with a transverse edge which is continuous with one short edge (27) and one long edge (21,23) and a screw hole offset from the symmetry axis of the drill point (25) towards the side of the long edge (21,23).

Abstract: A drill of simple construction, using commercially available tips or tips obtained by simply modifying them, well balanced in cutting resistance, and capable of drilling small-diameter holes.A main cutting edge (12) of a center-side cutting edge 1 is situated on a base line VP of a circular cone having its vertex on a point V on a tool central axis OO and a half vertical angle .alpha.. An intermediate cutting edge (2) having a length substantially equal to 1/2 of the length of the main cutting edge (12) is arranged on a straight line V'Q', extending parallel to a base line VQ, which is symmetrical to the base line VP with respect to the tool central axis OO and advanced ahead of the base line VQ for a lip height t mm in the axial direction, so that a straight line connecting the respective middle points of the intermediate cutting edge (2) and the main cutting edge (12) intersect the tool central axis (OO) substantially at right angles.

Abstract: A burnishing drill includes a cylindrical shank and a drill body connected to the shank. Drilling edges, first reaming edges and second reaming edges are formed on a first reduced diameter portion, a second reduced-diameter portion and a third reduced-diameter portion respectively located at a foremost end of the drill body. Each of the reaming edges is inclined with respect to the longitudinal axis of the drill at an angle which is set so as to be within a range of between 5.degree. and 30.degree.. During a boring operation using the drill, a hole is drilled by the drilling edges and the drilled hole is then worked by the first reaming edges and the second reaming edges to provide a smooth inner wall in the drilled hole. Since each of the reaming edges is formed to extend radially outward from the foremost end of the drill and incline axially in the rearward direction at a relatively small angle, the centering property can be greatly improved.

Abstract: A cutting insert includes a cutting edge extending obliquely relative to a center line of the insert. A chip breaking recess is spaced inwardly from the cutting edge and extends parallel hereto. A drill tool contains three inserts situated along a common diameter. The center insert has a cutting edge radially overlapping the cutting edges of the other two inserts. Each of the cutting edges of the other two inserts extends axially rearwardly and radially outwardly.

Abstract: A deburring tool for deburring bore edges of bores consists of a rotating tool holder on which one or more radially adjustable cutting knives are arranged. To ensure universal application of the deburring tool, additional cutting tools are arranged on the tool holder in axial distance from the known cutting knives so that additional chamfers and plane surfaces in the area of and outside the bore can be machined. Also, a drill or milling cutter can be connected to the tool holder on the front side of the tool holder.