Abstract: In a first aspect, the invention relates to a cutting tool that comprises a part (1) having an insert seat as well as a cutting insert (2) detachably connected in the same, which insert comprises a first serration connecting surface (3), which is formed of ridges spaced-apart by grooves, which ridges are arranged to engage grooves situated between ridges in a second serration connecting surface (4) serving as insert seat in said tool part (1). According to the invention, in one (3) of said serration connecting surfaces (3, 4), at least one enlarged ridge (18) is arranged between two spaced-apart fields (20a, 20b), which separately comprises a plurality of ordinary ridges of a certain size, which enlarged ridge is arranged to engage a correspondingly enlarged groove (19) in the second serration connecting surface (4). In additional aspects, the invention also relates to a cutting insert and a tool part as such.

Abstract: A tool bit suited to use in a machining apparatus for lathing of photoreceptor blanks includes a cutting portion which defines a plurality of projections. During lathing, the projections extend into the blank successively greater distances. When the blank is rotated, each projection cuts a successively radially inward portion of the workpiece. The resulting swarf is thinner and generally easier to handle than for a tool with a single cutting edge, thereby enabling vacuum suction of the swarf.

Abstract: Method for making a form-fitting connection between a tool insert and a tool holder of a rotatingly driven tool, wherein the tool holder has bearing surfaces by which forces or torques are transmitted to the tool insert, wherein the tool insert is made from a material harder than that of the tool holder and by sintering a green compact of powder. A sintered green compact for the tool insert is used as a hob, by which the bearing surfaces in tool holders are manufactured by punching or press-forming.

Abstract: A cutting tool includes a basic body and a cutting body that is fixable to the basic body via a male/female coupling. The coupling includes male-like fingers and female-like seats, which are delimited between elastically resilient projections. Each finger includes two converging wedge surfaces, which are pressable against a pair of diverging support surfaces of two adjacent projections. The axial angle of convergence of the two wedge surfaces of an individual finger differ from the angle of divergence of the two co-operating support surfaces of the projections, as long as the fingers are not loaded against the projections. In such a way, the removal of the cutting body from the basic body is facilitated.

Abstract: A deburring tool has a cutting insert slidably supported therein. The deburring cutting insert has a cylindrical major body and is moveable between a retracted position and an extended position by means of a biasing spring located alongside the cutting insert.

Abstract: In a method for producing a surface that is intended to form part of a coupling for use in chip removing machining, the surface includes a number of groove sets to allow locking by shape against another surface provided with grooves. Each groove set has a main direction, and the main directions of adjacently situated groove sets intersect. The number of groove sets are at least three, each groove set is produced in a separate cutting operation, and an equally large part of the surface is machined during each cutting operation. A surface that is intended to form part of a coupling for use in chip removing machining is also disclosed.

Abstract: A turning insert includes a chip-breaking surface and first and second clearance surfaces located at a corner of the insert. First and second edges are formed at a junction of the chip-breaking surface and the first and second clearance surfaces, respectively. The first edge defines a major cutting edge, and the second edge defines a finishing cutting edge. The major cutting edge is straight and transforms into the second edge by a sharp transition.

Abstract: The invention relates to a cutting insert having an essentially parallelepiped-shaped basic body with two larger spaced-apart longitudinal surfaces (10,11) which are connected to one another by two smaller transverse surfaces (12, 13) and two smaller longitudinal surfaces (14) designed as rake faces, wherein the smaller longitudinal surfaces (14) form with the adjacent surfaces a respective, encircling, closed cutting line which forms the cutting edges and rounded-off cutting corners, and the larger longitudinal surface (10, 11) merges on both sides via respective rounded-off edges into the smaller transverse surface (12, 13), and one of the rounded-off cutting corners is designed so as to project relative to a basic shape which is determined by the cutting lines, on both sides, of the larger longitudinal surfaces (10, 11) with the smaller longitudinal surfaces (14).

Abstract: A tool holder includes a shank portion, a head portion that includes an insert pocket defined by a seat surface, a first or radial support sidewall and a second or axial support sidewall, and a spherical contact point protruding from one of the first and second support sidewalls. The spherical contact point minimizes a contact area between a cutting insert mounted in the insert pocket and one of the first and second support sidewalls of the insert pocket. In one embodiment, the radial support sidewall includes two spherical contact points, and the axial support sidewall includes one spherical contact point. The spherical contact point may be formed by inserting a rivet-like structure into an aperture formed in the support sidewalls of the pocket.

Abstract: Boring tool and a cutting insert therefor. The abstract of the disclosure is submitted herewith as required by 37 C.F.R. §1.72(b). As stated in 37 C.F.R. §1.72(b): A brief abstract of the technical disclosure in the specification must commence on a separate sheet, preferably following the claims, under the heading “Abstract of the Disclosure.” The purpose of the abstract is to enable the Patent and Trademark Office and the public generally to determine quickly from a cursory inspection the nature and gist of the technical disclosure. The abstract shall not be used for interpreting the scope of the claims. Therefore, any statements made relating to the abstract are not intended to limit the claims in any manner and should not be interpreted as limiting the claims in any manner.

Abstract: A tool for chip removing machining, including a basic body and a cutting insert detachably connected to the basic body via an interface. The interface includes a first connecting surface formed in the basic body in which a chute is formed that has two side-flank surfaces diverging from a bottom. The interface also includes a second connecting surface formed in the cutting insert in which there are formed a number of male members having converging side-flank surfaces that abut against the side-flank surfaces of the chute, and at least one transverse shoulder surface that abuts against a transverse stop surface in the connecting surface of the basic body.

Abstract: A turning tool including a basic body having an insert seat, an indexable turning insert having a triangular basic shape, and a tightening element fixing the turning insert in the insert seat. The insert includes an upperside and an underside between which three side surfaces extend that are situated in a first imaginary, equilateral triangle and therefore converge in pairs at an angle of 60° toward corners in which cutting edges are included. The turning insert is engaged with the insert seat via an interface that includes elongate and straight, female-like and male-like engagement members, which are in engagement with each other in order to prevent turning of the turning insert. The insert seat includes a supporting surface having a corner section against which an active corner of the turning insert is applied.

Abstract: A turning tool including a basic body having a pocket, a shim plate mounted in the pocket, and an indexable turning insert mounted in the pocket. The pocket opens in a front surface and in a side surface of the basic body, and accommodates two spaces spaced-apart level-wise, a lower space housing the shim plate and delimited by a bottom surface and two side support surfaces, which form an acute angle with each other, one of which is a primary side support surface and the other one a secondary side support surface, and an upper space housing the turning insert. The shim plate includes an upperside and an underside between which a pair of primary and secondary contact surfaces extend, which form an acute angle with each other and are urged against the primary and secondary side support surfaces in the pocket, as well as a pair of inactive surfaces extend in the form of an outer end surface and an outer side limiting surface, which together delimit a supporting corner section of the shim plate.

Abstract: A cutting insert having a front cutting edge and a connecting surface including male- and/or female-like engagement portions, in order to rigidly secure the cutting insert, a geometrically predetermined reference locus serving as a force-application spot for the clamping of the cutting insert. Simultaneously active engagement portions are of only two types—a first, elongate engagement portion, which is located between the front cutting edge and the reference locus, and a second, elongate engagement means, which is oriented at an angle to the first engagement portion and situated at a greater distance from the front cutting edge than the reference locus. In such a way, it is guaranteed that a tightening force always is applied to the cutting insert in a substantially triangular area, which is defined by the free ends of the engagement portions. Furthermore, a tool for chip removing machining, as well as an attachment, e.g., a shim plate, for such tools is provided.

Abstract: A universal turning and milling tool applied in turning, milling, and drilling includes a tool blade with one end disposed with a holder to accommodate a disposable insert to be locked in the holder with a screw; a threaded hole being disposed at the center of the holder; a bevel angle ? inclined downward being defined by the surface of the holder and the turning central line (T.C.L.) of the tool; and the proper bevel angle ? being defined between a screw hole central line (S.C.L.) of the threaded hole and the T.C.L of the tool; the S.C.L. of the threaded hole of the holder straying from the T.C.L. of the tool for a mild distance; and only a cutting edge of the insert straying from the T.C.L. operates to cut and another cutting edge on the other side of the insert is idled when the tool revolves.

Abstract: A toolholder and cutting insert for a toolholder assembly wherein the cutting insert has a tapered shank which provides a resilient interference fit with a tapered section of a bore extending within the toolholder. Additionally, a rearwardly facing face on the cutting insert abuts with a forwardly facing surface on the toolholder to properly locate the cutting insert within the toolholder.

Abstract: A tool holder includes a shank portion, a head portion that includes an insert pocket defined by a seat surface, a first or radial support sidewall and a second or axial support sidewall, and a spherical contact point protruding from one of the first and second support sidewalls. The spherical contact point minimizes a contact area between a cutting insert mounted in the insert pocket and one of the first and second support sidewalls of the insert pocket. In one embodiment, the radial support sidewall includes two spherical contact points, and the axial support sidewall includes one spherical contact point. The spherical contact point may be formed by inserting a rivet-like structure into an aperture formed in the support sidewalls of the pocket.

Abstract: A tool for chip-removing machining includes a holder on which in indexible cutting insert is mounted. The holder includes a first base surface on which a plurality of male parts are disposed to define an insert seat. The insert includes generally parallel second and third base surfaces, each having a plurality of female parts disposed therein. The insert is invertible such that the female parts of one of the second and third base surfaces receive respective male parts of the holder. A fastener secures the insert on the seat, with the male parts tightly fitted in the female parts. The male parts are flexible relative to the first base surface to ensure a firm abutment of the male parts with surfaces of respective female parts.

Abstract: A tool body includes an insert seat for receiving a cutting insert for chip-removing machining. The insert seat includes a bottom surface and support surfaces upstanding from the bottom surface. Each support surface comprises at least three ridges separated by grooves. Each groove has a depth greater than zero and no greater than 0.015 mm. An insert mounted in the seat by a screw has a center hole whose axis is offset from the axis of a threaded hole of the body in which the screw is connected. That offset distance creates a prestress of the insert toward the ridges. The depth of the grooves (i.e., the height of the ridges) is substantially less than the distance of the offset.

Abstract: A cutting tool includes a tool body having a plurality of insert receiving pockets and at least one cutting insert mounted in each pocket. Each pocket includes a pocket base wall, a side wall and a stress relief groove. The tool body also includes a top surface including a first portion and a second portion, and a stress splitter that extends from the stress relief groove and intersects the first and second portions. The stress splitter may be in the form of a sharp peak or ridge, a radiused peak, rounded mass or protuberance, and the like. The stress splitter reduces a maximum amount of stress in an area of the stress relief groove during a machining operation.

Abstract: An indexible cutting bit includes an upper side of polygonal contour defining at respective corners thereof a secondary cutting edge which extends between first and second main cutting edges. The secondary cutting edge includes, in order of closeness to the first main cutting edge: a convexly curved transition first portion extending from an end of the first main cutting edge, a concavely curved second portion of a second radius, a convexly curved third portion of a third radius, a concavely curved fourth portion of a fourth radius, a convexly curved fifth portion of a fifth radius, a concavely curved sixth portion of a sixth radius, and a convexly curved transition seventh portion extending to the second main cutting edge.

Abstract: An insert retention screw has a head with a radius that is a sufficient size to fit within a mounting hole of a cutting insert and seat within a seating plane within the mounting hole that is generally perpendicular to the axis of the insert when the screw is at an angle in a range of about 0–15 degrees. The retention screw is provided for holding a cutting insert in the pocket of a tool body. The pocket is partially defined by a floor and a seating surface. A threaded hole is at an angle that is taken with reference to the pocket floor. The insert has a mounting hole passing therethrough. The retention screw passes through the mounting hole and threads into the threaded hole so as to draw the insert against the seating surface.

Abstract: A tool for chip-removing machining includes an insert holder, a cutting insert for chip-removing machining, and a fixing element for fixing the cutting insert in an insert seat of the insert holder. The insert has fingers projecting from a bottom side of the insert. The insert seat has a number of elastically flexible portions forming recesses therebetween which receive respective fingers of the insert. Contact surfaces of the fingers engage respective contact surfaces of the flexible portions to cause the flexible portions to flex elastically as the fingers become wedgingly secured in the recesses.

Abstract: A cutting tool has a tool body in which a cutting insert is secured to an insert pocket in the tool body by a fastener. In contrast to the use of a threaded clamping screw, the fastener remains in engagement with the tool body during all stages of the attachment and clamping, or unclamping and removal of the cutting insert. The fastener is rotatable between a clamping position and a non-clamping position by means of one of two keys. One key being capable of engaging one of the fastener's ends, and the other key being capable of engaging the other of the fastener's ends. This is particularly convenient for circumstances where the approach to one or the other of the fastener's ends may be obstructed.

Abstract: A tangential indexable cutting insert can be used for metal cutting processes in general and for radial and axial turning of a stepped square shoulder in particular. The cutting insert exhibits 180° rotational symmetry about three mutually perpendicular axes. The cutting insert has generally “S”-shaped cutting edges extending between raised and lowered corners. The cutting edges and side surfaces are concave in an end view of the cutting insert. The cutting insert enables radial and axial turning operations of a square shoulder with unlimited depth of cut.

Abstract: A tool for the fine-turning of grooves in workpieces including a basic body having a rearwardly extending mounting part, and a forwardly projecting bracket. The bracket includes a narrow neck part and an enlarged support part disposed at an end of the neck part. The support part, which forms an insert seat, extends laterally from the neck part wherein the seat is arranged asymmetrically with respect to an imaginary center line of the basic body. A cutting insert includes a bottom side supported on the insert seat. The insert includes two spaced apart convexly arched side cutting edges arranged so that the imaginary center line passes therebetween. A hole is provided through the insert for receiving a fastening screw. The bottom side and the insert seat include mutually engaging stabilizing structures preventing angular displacement of the insert about an axis of the hole.

Abstract: A cutting insert comprises first and second polygonally-shaped main faces arranged substantially parallel to one another, and a side face structure interconnecting the first and second main faces to define a peripheral edge. At least the first main face includes at least one projection extending to the peripheral edge, the projection formed by: a portion of the first main surface (defining a relief surface), a portion of the side face structure (defining a rake surface), and a portion of the peripheral edge (defining a cutting edge). The insert includes support surfaces defined by a portion of the second main face, and by portions of the side surface structure other than the rake surface.

Abstract: A tangential cutting insert having two identical opposing end surfaces with two identical opposing major side surfaces and two identical opposing minor side surfaces extending between them. Each end surface has a peripheral edge containing cutting edges and four corners of which two are lowered and two are raised. Each end surface is provided with at least one projecting abutment member having a projecting abutment surface, wherein in a side view of either major side surface, the at least one projecting abutment surface is concave.

Abstract: An apparatus for chip removing machining includes first and second parts which are intercoupled by a coupling. The coupling includes two interacting surfaces disposed on the first and second parts, respectively. The interacting surfaces are profiled to intermesh with one another to define an intermeshing region of the coupling. Each of the surfaces is profiled with first and second sets of grooves which define first and second main directions, respectively, which extend transversely to one another. At least one groove on each of the surfaces extends across less than the entire intermeshing region, wherein the surfaces define only one coupling position for the first and second parts.

Abstract: A cutting insert for metalworking operations has an insert core with a pair of cutting portions having cutting tips extending therefrom such that a toolholder having a pocket to accept such a core is suitable to accept different cutting inserts having a common core plus different cutting portions. As a result, for example, an 80° diamond, a 55° diamond and a 35° diamond cutting insert may all be utilized within a common toolholder. The invention is also directed to a toolholder that will accept such a variety of cutting inserts.

Abstract: A tool for chip removing machining includes an insert holder and a cutting insert attached thereto. The holder includes a longitudinal center axis and terminates in a support surface at a front end of the holder. The support surface defines a seat to which the insert is removably attached. The support surface forms a 45-degree angle with the center axis. The cutting insert includes a contact surface for mounting the insert to the seat, and a plurality of fingers projecting generally radially with respect to the center axis. Each finger includes a cutting edge and an associated chip surface.

Abstract: A toolholder for a small-size insert having a shoulder for use with a machine tool for grooving, boring and turning has a substantially planar surface portion in an end portion which defines at least one insert-receiving recess extending inwardly into the body of the toolholder, and the end portion defining at least one abutment surface against which the shoulder of the insert may abut to readily orient and rapidly and readily secure the insert in the toolholder.

Abstract: A cutting tool has an insert shaped as a parallelogram that is detachably mounted by a clamp screw 4 on a tip mounting face of a holder. Concave grooves are formed like parallel stripes on the tip mounting face of the holder, and convex lines are formed on the abdominal face of the insert to be fitted in the concave grooves, so that the insert is clamped by the clamp screw to the holder in a state where the convex lines are fitted in the concave grooves on the tip mounting face.

Abstract: A cutting insert for milling cam shafts includes first and second surface interconnected by a third surface, and at least one cutting edge. The cutting edge includes a straight first cutting edge section, a straight second cutting edge section, and a generally convex third cutting edge section, all adjoining one another. The first section extends along the junction between the first and third surfaces. The second section extends along the junction and includes a first end adjoining an end of the first section. The second is inclined at an obtuse angle from one end of the first section in a direction away from the third surface. The third section extends along the junction and adjoins a second end of the second section. The third section is of generally convex shape and extends over an angular range greater than 90°. The first, second and third sections lie in the third surface.

Abstract: An indexible cutting insert has a connecting surface formed by alternating parallel ridges and grooves. Each ridge is defined by a pair of flanks which converge in an outward direction. Each ridge includes a convexly curved surface portion for making line contact with a corresponding ridge of a support surface. The convexly curved surface is spaced from outer and inner ends of the respective flank.

Abstract: A tool for the machine working of workpieces is more particularly provided for universal machines, which automatically work very small workpieces by different lathe working operations. A cutting insert (13) can be fixed in a tool holder (14) by means of a fixing screw (19). The cutting insert (13) is constructed as a reversing plate and has two conical receptacles for the conical gripping head (25) of the fixing screw (19). This reversing plate has several use possibilities, such as grooving, plunge and turn, threading, front turn, back turn and cut off. The central opening (30) in the cutting insert is connected by means of a slot (36) to the narrower trapezoidal surface (35) of the cutting insert, the slot (36) being sufficiently wide to fit over the shank of the fixing screw (19). Thus, after loosening the fixing screw, the cutting insert can be removed laterally and correspondingly fitted again. The screw (19) is captive and can also be operated from the back (48) of the tool holder (14).

Abstract: A cutting blade 16, and a method of securing the blade 16 in a reamer 11 having an axial recess 19 in the body 13 of the reamer. The cutting blade 16 has parallel serrations 35 in its rear face 37 extending normally of each cutting edge 34 and is clamped to mutually interengagable parallel serrations 36 on the reamer 11 which extend radially thereof. The cutting edge 34 of the blade 16 is adjusted to a new position by movement of the blade along the radial serrations 36 using a single adjuster means 42.

Abstract: Cutting tool (1) with a cutting insert (3), on the front edge (14) of which there is a first major cutting edge (15) and an approximately U-shaped indentation (18) that interrupts said first major cutting edge (15), whereby each side leg (19, 20) of the indentation (18) forms a minor cutting edge, and the base (21) of the indentation (18) forms a second major cutting edge (22) which is recessed in the feed direction (V) behind the first major cutting edge (15), and whereby the cutting insert (3) is formed by at least two separate sections (4a, 4b), each of which carries a portion of the indentation (18).

Abstract: A tangential cutting insert having two identical opposing end surfaces with two identical opposing major side surfaces and two identical opposing minor side surfaces extending between them. Each end surface has a peripheral edge containing cutting edges and four corners of which two are lowered and two are raised. Each end surface is provided with at least one projecting abutment member having a projecting abutment surface, wherein in a side view of either major side surface, the at least one projecting abutment surface is concave.

Abstract: A turning tool includes a holder and an cutting insert clamped to the holder. The insert and the holder include respective support surfaces pressed against one another. Each of those support surfaces includes first and second sets of ridges oriented substantially perpendicular to one another. The ridges on the insert's support surface engage respective ridges on the holders support surface to prevent movement of the insert relative to the holder in two directions oriented perpendicularly to one another. At least one of the first and second support surfaces has its first and second sets of ridges arranged in respective first and second regions of that support surface. The other support surface could have its sets of ridges arranged in a similar fashion, or its sets of ridges could occupy the same region of the support surface to form a waffle pattern.

Abstract: A cutting tool has at least one insert receiving pocket with a cutting insert retained therein. The insert receiving pocket has a base wall and a side wall transversely directed to the base wall with a circular recess having a peripheral wall extending downwardly from the base wall. A threaded bore extends downwardly from the lower wall of the recess. The cutting insert has an upper surface, a lower surface and a cylindrical protrusion having peripheral surface extending downwardly from the lower surface. A through bore extends through the cutting insert from the upper surface. A retaining screw passes through the through bore and threadingly engages the threaded bore with the peripheral surface abutting the peripheral wall and with the lower surface abutting the base wall.

Abstract: An indexible turning tool for chip forming machining, includes a holder equipped with insert pockets receiving replaceable inserts, as well as a securing portion intended to be received in a tool machine. At least one of the replaceable inserts has a main plane that extends laterally in relation to the tool's axial direction.

Abstract: According to the invention, an insert holder (10) exists for indexable cutting inserts. In connection with the insert seat, a clamping device is located, including an L-shaped toggle joint (18) of which one arm (21) is received in a hole (13) in the cutting insert and of which the second arm (22) is actuated by end pressure member (19). Characteristic of the invention is that the hole (13) in the cutting insert is a blind hole and that the end portion of the arm (22) co-operating with the member (19) has a V-shaped cavity (23) in order to enclose a waist portion (24) of the member (19).

Abstract: A toolholder for a small-size insert having a shoulder for use with a machine tool for grooving, boring and turning has a substantially planar surface portion in an end portion which defines at least one insert-receiving recess extending inwardly into the body of the toolholder, and the end portion defining at least one abutment surface against which the shoulder of the insert may abut to readily orient and rapidly and readily secure the insert in the toolholder.

Abstract: A cutting bit for a milling tool includes a flat upper face which at least partially serves as a rake face, and a lower support face which is substantially parallel thereto. The upper face and the lower face are connected together by a peripherally extending edge face. The edge surface includes six sides each interconnecting the upper and lower faces. Each side includes first and second faces oriented in non-coplanar relationship, wherein each first face intersects the upper face to form therewith a secondary cutting edge, and each second face intersects the upper face to form therewith a main cutting edge arranged non-colinearly with respect to the secondary cutting edge. A alternating ones of the first faces form a first angle of substantially 60° to one another, and alternating ones of the second faces form a second angle of substantially 60° to one another.

Abstract: An apparatus for chip removing machining includes first and second parts which are intercoupled by a coupling. The coupling includes two interacting surfaces disposed on the first and second parts, respectively. The interacting surfaces are profiled to intermesh with one another to define an intermeshing region of the coupling. Each of the surfaces is profiled with first and second sets of grooves which define first and second main directions, respectively, which extend transversely to one another. At least one groove on each of the surfaces extends across less than the entire intermeshing region, wherein the surfaces define only one coupling position for the first and second parts.

Abstract: A cutting insert is clamped in a pocket of a holder by a top clamp assembly which includes a clamp arm screwed to the holder, and a clamp plate interposed between the insert and a front part of the clamp arm. The clamp plate is formed of a harder and more wear-resistant material than the clamp arm and transmits clamping forces from the clamp arm to the cutting insert. The hard clamp plate shields the clamp arm from being impacted by chips generated during a machining operation, thereby minimizing wearing of the clamp arm.

Abstract: The invention relates to a ceramic cutting insert for cutting tools of the type which include a clamp with a nose intended to grip into a recess (5) in the cutting insert in order to keep the cutting insert firmly in place in an insert seat in a tool holder. The recess (5) has a rotationally symmetrical shape and comprises an inner cavity (18) which is delimited by a cylindrical or slightly conical wall surface (19) said cavity extends from the far end of the inner cavity and expands outwards by ever increasing its diameter in the direction from the inner cavity to the entrance opening in the said upper or lower sides.

Abstract: A metal cutting tool having an indexable cutting insert retained in an insert pocket of an insert holder. The cutting insert has two opposing side surfaces with a peripheral edge surface extending therebetween and a plurality of cutting portions. The peripheral edge surface has a plurality of abutment sections, each abutment section lying on a portion of a sidewall of an imaginary regular polygon. A plurality of cutting portions extend outwardly from the imaginary polygon and are equal in number to the number of side walls thereof. Each abutment section is located between two cutting portions. The insert holder has an insert pocket in which the cutting insert is retained with the peripheral edge surface being abutted at two abutment sections by two support walls of the insert pocket, the support walls being fixed and integral parts of the insert holder.

Abstract: A metal cutting tool includes a stationary tool holder and a mounting body therefor. The tool holder includes a first coupling part which is restrained by a second coupling part on the mounting body. The coupling parts are coaxially arranged one inside of the other. The coupling pars are conical as viewed in a longitudinal section plane containing the axis. The first coupling part includes teeth projecting generally radially with respect to the axis and received in respective radially-open recesses formed in the second coupling part. Each of the teeth makes contact with a wall of the respective recess at first and second contact places which are respectively situated on opposite sides of a generally radial line of symmetry of the tooth. The contact places are operable to transmit a restraining force from the second coupling part to the second coupling in respective directions. A restraining angle in the range of −5° to +45° is formed at each contact place.