SWISS TURNING INSERT WITH CHIP FORMER ARRANGEMENT COMPRISING UPWARDLY EXTENDING RIDGE

Abstract

A swiss insert includes a chip former arrangement. The chip former arrangement includes a ridge separated on each side from a cutting edge's sub-edge by a chip surface. In a side view, each sub-edge extends in a straight line.

Claims

1. A swiss insert comprising: opposite insert first and second side surfaces; opposite insert upper and lower surfaces connecting the insert first and second side surfaces; opposite insert front and rear surfaces connecting the insert upper and lower surfaces and the insert first and second side surfaces; a first corner formed at an intersection of the first and second side surfaces and the insert upper and front surfaces; a second corner formed at an intersection of the first and second side surfaces and the insert upper and rear surfaces; a third corner formed at an intersection of the first and second side surfaces and the insert lower and front surfaces; a fourth corner formed at an intersection of the first and second side surfaces and the insert lower and rear surfaces; a screw hole opening out to the insert first and second side surfaces; an insert thickness axis (A.sub.T) extending perpendicular to, and extending through, the insert first and second side surfaces; an insert height axis (A.sub.H) extending perpendicular to the insert thickness axis, and extending through the insert upper and lower surfaces; an insert length axis (A.sub.L) extending orthogonal to the insert thickness and height axes, and extending through the insert front and rear surfaces; a length plane (P.sub.L) defined by the insert length axis (A.sub.L) and the insert height axis (A.sub.H); a thickness plane (P.sub.T) defined by the insert thickness axis (A.sub.T) and the insert length axis (A.sub.L); a height plane (P.sub.H) defined by the insert height axis (A.sub.H) and the insert thickness axis (A.sub.T); a maximum insert thickness measurable along the insert thickness axis; a maximum insert height measurable along the insert height axis and being greater than the maximum insert thickness; a maximum insert length measurable along the insert length axis and being greater than the maximum insert height; the insert height axis (A.sub.H) defining an upward direction (D.sub.U) from the center of the insert towards the insert upper surface, and defining a downward direction (D.sub.D) opposite to the upward direction; the insert thickness axis (A.sub.T) defining a first side direction (D.sub.S1) from the center of the insert towards the insert first side surface, and defining a second side direction (D.sub.S2) opposite to the first side direction; the insert length axis (A.sub.L) defining a forward direction (D.sub.F) from the center of the insert towards the insert front surface, and defining a rearward direction (D.sub.R) opposite to the forward direction; the first corner comprising: a cutting edge, and a chip former arrangement formed at the upper surface; the cutting edge comprising: a first sub-edge extending along an intersection of the upper surface and the first side surface and following a straight line in a view along the second side direction (D.sub.S2); a second sub-edge extending along an intersection of the upper surface and the second side surface and following a straight line in a view along the first side direction (D.sub.S1); a third sub-edge extending along an intersection of the upper surface and the front surface; a first corner edge connecting the first sub-edge the third sub-edge; and a second corner edge connecting the second sub-edge the third sub-edge; the chip former arrangement comprising: a first chip surface adjacent to the first sub-edge and extending from the third sub-edge to a first rear chip edge, thereby defining a first cutting depth (L.sub.C1); a second chip surface adjacent to the first sub-edge and extending from the third sub-edge to a second rear chip edge, thereby defining a second cutting depth (L.sub.C2); a general cutting depth (L.sub.GC) of the chip former arrangement being defined as (i) the smaller of the first and second cutting depths (L.sub.C1, L.sub.C2), or (ii) if the first and second cutting depths are equal, the depth of both the first and second cutting depths (L.sub.C1, L.sub.C2); and a ridge connected to the first and second chip surfaces, and comprising a ridge front end proximate to the third sub-edge and a ridge rear end located further than the ridge front end from the third sub-edge, the ridge extending in the upward direction from the location of the upper surface where the ridge and the first and second chip surfaces connect; wherein adjacent to the cutting edge the insert's first and second side surfaces and front surface are configured as relief surfaces by: the first side surface tapering in a combined downward and second side direction; the second side surface tapering in a combined downward and first side direction; and the front surface tapering in a combined downward and rearward direction.

2. The insert according to claim 1, wherein in a view of the first cutting portion along the downward direction: one or both of the first and second corner edges comprises a wiper portion connected to the third sub-edge and extending in a straight line extending at a right angle with a nearer of the first and second sub-edges; and the third sub-edge is inwardly recessed relative to each wiper portion.

3. The insert according to claim 2, wherein each of the first and second corner edges comprises: said wiper portion, and a convexly shaped portion connected at a first end thereof to a nearer of the first and second sub-edges and at a second end thereof to said wiper portion.

4. The insert according to claim 1, wherein in a view of the first cutting portion along the downward direction, one or both of the first and second chip surfaces have a tapering shape.

5. The insert according to claim 4, wherein each tapering shape is wider adjacent to the third sub-edge than at another position spaced further apart from the third sub-edge.

6. The insert according to claim 1, wherein one or both the first and second chip surfaces have a planar shape.

7. The insert according to claim 1, wherein one or both the first and second chip surfaces form a side angle α with the thickness plane (P.sub.T), the side angle α fulfilling the following condition: −15°<α<15°.

8. The insert according to claim 1, wherein the entire cutting edge lies in a cutting edge plane having a height of less than 150 microns.

9. The insert according to claim 1, wherein the insert is rotationally symmetric only at an angle of 180° about an axis parallel with the thickness axis (A.sub.T) and extending through the center of the insert.

10. The insert according to claim 1, wherein the ridge comprises first and second side concave portions connecting the ridge to the chip surfaces, the first concave side portion opening up in the first side direction (D.sub.S1) and the second concave side portion opening up in the second side direction (D.sub.S2).

11. The insert according to claim 1, wherein the ridge front end comprises a concave front portion opening up in the forward direction (D.sub.F).

12. The insert according to claim 1, wherein between the ridge front end and the third sub-edge, the chip former arrangement comprises an intermediary plateau no higher in the upward direction (D.sub.U) than 100 microns above the first and second sub-edges.

13. The insert according to claim 12, wherein the intermediary plateau has a planar shape.

14. The insert according to claim 1, wherein, in view along the rearward direction (D.sub.R), a width (L.sub.R) of the ridge, at a height above the first and second side sub-edges, is less than half the overall thickness (L.sub.I) between the first and second side sub-edges measured along the thickness axis (A.sub.T).

15. The insert according to claim 1, wherein the ridge is elongated in a direction parallel to the insert length axis (A.sub.L).

16. The insert according to claim 1, wherein a front spacing length (L.sub.FS) between the third sub-edge and the ridge front end, measurable along the insert length axis (A.sub.L), is at least 5% of the general cutting depth (L.sub.GC).

17. The insert according to claim 16, wherein the front spacing length (L.sub.FS) is defined as 10%±5% of the general cutting depth.

18. The insert according to claim 1, wherein in a view along each of the first and second insert side directions (D.sub.S1, D.sub.S2): the ridge has a basic convex shape; the ridge front end tapers in a combined forward and downward direction; and the ridge rear end tapers in a combined rearward and downward direction.

19. The insert according to claim 18, wherein: a rear edge plane (P.sub.RE) is parallel to the height plane (P.sub.H) and spaced apart from the third sub-edge by said general cutting depth (L.sub.GC); and a rear spacing length (L.sub.RS) between where the ridge rear end starts tapering in said combined rearward and downward direction, and the rear edge plane (P.sub.RE), is at least 5% of the general cutting depth (L.sub.GC).

20. The insert according to claim 19, wherein the rear spacing length (L.sub.RS) is defined as 15%±10% of the general cutting depth (L.sub.GC).

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0084] For a better understanding of the subject matter of the present application, and to show how the same may be carried out in practice, reference will now be made to the accompanying drawings, in which:

[0085] FIG. 1A is a view along a downward direction (hereinafter also called a “top view”) of a tool assembly;

[0086] FIG. 1B is a view along a rearward direction (hereinafter also called a “front end view”) of the tool assembly in FIG. 1A;

[0087] FIG. 1C is a view along a side direction (hereinafter also called a “side view”) of the tool assembly in FIG. 1A;

[0088] FIG. 2A is a top view of a tool of the tool assembly in FIG. 1A;

[0089] FIG. 2B is a front end view of the tool in FIG. 2A;

[0090] FIG. 2C is a side view of the tool in FIG. 2A;

[0091] FIG. 3A is a top view of an insert of the tool assembly in FIG. 1A (i.e. this is a view along a downward direction, noting that an identical view, except rotated 180°, would be shown along an upward direction);

[0092] FIG. 3B is a front end view of the insert in FIG. 3A (i.e. this is a view along a rearward direction, noting that an identical view, except rotated 180°, would be shown along a forward direction);

[0093] FIG. 3C is a side view of the insert in FIG. 3A (i.e. this is a view along a second side direction);

[0094] FIG. 3D is an enlarged partial front end view of the insert as shown in FIG. 3B;

[0095] FIG. 3E is an enlarged partial top view of the left hand side of the insert as shown in FIG. 3A;

[0096] FIG. 3F is an enlarged partial side view of the left hand side of the insert as shown in FIG. 3C;

[0097] FIG. 4 is a partial top view of the tool assembly in FIG. 1A and a workpiece held by a partially shown bushing in a configuration typical of a swiss-style CNC machine;

[0098] FIG. 5A is a front view of a gang comprising four tool assemblies of the type in FIG. 1A; and

[0099] FIG. 5B is a side view of the gang in FIG. 5A.

DETAILED DESCRIPTION

[0100] Referring to FIG. 1A to 1C, illustrated is a tool assembly 10 comprising an insert 12, a tool 14 and a screw 16 for securing the insert 12 to the tool 14.

[0101] Referring to FIGS. 3A to 3C, the insert 12 can comprise first, second, third and fourth corners 18A, 18B, 18C, 18D. The first and third corners 18A, 18C, in this example, are cutting corners, meaning that each such corner comprises a cutting edge 20A, 20B and a chip former arrangement 22A, 22B.

[0102] Insert thickness, height and length axes A.sub.T, A.sub.H, A.sub.L extend through insert first side, second side, upper, lower, front and rear surfaces 24A, 24B, 26A, 26B, 28A, 28B, and define upward, downward, first side, second side, forward and rearward directions D.sub.U, D.sub.D, D.sub.S1, D.sub.S2, D.sub.F, D.sub.R and thickness, height and length planes P.sub.T, P.sub.H, P.sub.L. Maximum insert thickness, height and lengths L.sub.T, L.sub.H, L.sub.L are measured parallel to the insert thickness, height and length axes A.sub.T, A.sub.H, A.sub.L, respectively.

[0103] The insert upper surface 26A could also be described as extending rearwardly from a first upper end 26A1 to a second upper end 26A2. As best shown in FIG. 3B, at least an upper abutment portion 26A3 of the insert upper surface 26A can be slanted in the upward and second directions D.sub.U, D.sub.S2. It will be understood hereinafter, that the insert upper surface 26A is only used for contacting the tool 14 after indexing thereof.

[0104] The insert lower surface 26B could also be described as extending rearwardly from a first lower end 26B 1 to a second lower end 26B2. At least a lower abutment portion 26B3 of the insert lower surface 26B can be slanted in the downward and second side directions D.sub.D, D.sub.S2.

[0105] The second side surface 24B can be formed with a bearing configuration generally designated 30. The bearing configuration 30 can comprise a planar shaped bearing surface 30A, extending parallel with the length plane P.sub.L and preferably is ground for precision mounting of the insert 12 to the tool 14.

[0106] The insert front surface 28A can be generally described as tapering in the downward and rearward directions D.sub.D, D.sub.R from the first upper end 26A1 to the first lower end 26B1. Additionally, at a front abutment portion 28A1 which is spaced apart from the cutting edge 20A can be further defined as being slanted in a combined downward, rearward and first side direction D.sub.U, D.sub.R, D.sub.S1.

[0107] The insert rear surface 28B comprises a correspondingly construction to the insert front surface 28A, bearing in mind the rotational symmetry of the insert 12. To elaborate, the insert rear surface 28B comprises a slanted rear abutment portion 28B 1 being slanted in a combined downward, rearward and first side direction D.sub.U, D.sub.R, D.sub.S1.

[0108] A screw hole 32 opens out to both the insert first and second side surfaces 24A, 24B. In cases where the screw hole 32 is centrally located in the first and second side surfaces 24A, 24B, the insert thickness axis A.sub.T also can also extends through a center I.sub.C of the insert 12 and can constitute a central axis (which in this case is also the insert thickness axis A.sub.T, and also constitutes a screw axis in this case) about which the insert 12 can be indexed. Stated differently the insert 12 can be rotationally symmetric by exactly and only 180° about the central axis, which in this case is coaxial with the insert thickness axis A.sub.T.

[0109] Since both the first and third corners 18A, 18C are identical, only the first corner 18A will be described hereinafter.

[0110] As shown in FIG. 3A, the cutting edge 20A can continuously extend around the upper surface of first corner 18A, comprising a first sub-edge 34A, a second sub-edge 34B and a third sub-edge 34C, the first and third sub-edges 34A, 34C connected by a first corner edge 34D, and the second and third sub-edges 34B, 34C connected by a second corner edge 34E.

[0111] It is preferred that the first and second sub-edges 34A, 34B are substantially parallel. For example, in FIG. 3B it is noted that both the first and second sub-edges lie within a cutting edge plane P.sub.CE having a height H.sub.CE of 10 microns. It will be understood that each statement in the present application of a plane having a height (or corresponding dimension if the plane is oriented differently) could alternatively be stated as the elements specified as being within a certain distance of a plane having a theoretical height of zero. To explain by way of example, if the cutting edge plane P.sub.CE has a theoretical height H.sub.CE of zero, both the first and second sub-edges 34A, 34B extend less from the cutting edge plane P.sub.CE than a distance of: ±5 microns.

[0112] Similarly, the entire cutting edge 20A can preferably lie within the cutting edge plane P.sub.CE should it have a height H.sub.CE of 150 microns, more preferably 100 microns. Stated differently, the cutting edge can extend no further from the cutting edge plane P.sub.CE (assuming it has a theoretical height H.sub.CE of zero) than a distance of: ±75 microns, or more preferably ±50 microns.

[0113] Referring specifically to FIG. 3E, it is illustrated that the first corner edge 34D can comprise a first wiper portion 34D1 connected to a first corner portion 34D2 at a first corner discontinuity point 34D3. The second corner edge 34E can comprise a second wiper portion 34E1 connected to a second corner portion 34E2 at a second corner discontinuity point 34E3.

[0114] Each of the first and second wiper portions 34D1, 34E1 can form a right angle (e.g., the first wiper portion being exemplified in FIG. 3E with a right angle symbol) with a nearer of the first and second sub-edges 34A, 34B as illustrated.

[0115] The first and second wiper portions 34D1, 34E1 connect to the third sub-edge 34C at first and second discontinuity points 35A, 35B which constitute extremity points thereof.

[0116] Between the first and second discontinuity points 35A, 34B the third sub-edge 34C extend inwardly (i.e. in the view shown in FIG. 3E and towards the rearward direction D.sub.R). Notably, the third sub-edge 34C can be, in its entirety, rearwardly located of a front edge plane P.sub.FE along which the first and second wiper portions 34D1, 34E1 lie.

[0117] The third sub-edge 34C can further comprise, in a view along the downward direction (FIG. 3E), a central portion 35C which is concavely shaped in this view and extends to third and fourth discontinuity points 35D, 35E. However, the central portion 35C, in a view along the rearward direction (FIG. 3D) nonetheless extends in a straight line, preferably parallel with the thickness plane P.sub.T.

[0118] To further describe the third sub-edge 34C in the view shown in FIG. 3D, it is noted that the chip former arrangement 22A comprises a ridge 36 which in turn comprises first and second concave side portions 37A, 37B, which will be described further hereinafter.

[0119] At the third sub-edge 34C, the concave side portions 37A, 37B form first and second front concave edge portions 35F, 35G shown to be concave along both the rearward direction (i.e. the view shown in FIG. 3D) and along the downward direction (i.e. the view shown in FIG. 3E). The first and second front concave edge portions 35F, 35G respectively extend from the third and fourth discontinuity points 35D, 35E to fifth and sixth discontinuity points 35H, 35I (the latter being visible in only a view along the downward direction).

[0120] At the third sub-edge 34C, the first and second chip surfaces 38A, 38B form first and second straight edge portions 35J, 35K shown to be straight both the rearward direction (i.e. the view shown in FIG. 3D).

[0121] The first straight edge portion 35J extends from the first discontinuity point 35A to the fifth discontinuity point 35H.

[0122] The second straight edge portion 35K extends from the second discontinuity point 35B to the sixth discontinuity point 35I.

[0123] Additionally, as shown in this view, both of first and second first corner portions 34D2 34E2 are convexly shaped portions (rather than a possible alternative of sharp angled corners).

[0124] It will be noted that both the non-smooth path of the third sub-edge 34C, or stated differently the different heights thereof when viewed in both the rearward and downward directions can be advantageous in destabilization of workpiece chips, by causing different portions thereof to deflect in different directions (for causing chip breakage at a desired length).

[0125] Directing attention to all of FIGS. 3A to 3F, the first chip former arrangement 22A can comprise the first and second chip surfaces 38A, 38B the ridge 36 connected to the first and second chip surfaces 38A, 38B, and an intermediary plateau 40 (the intermediary plateau is present as a result of a preferred production method and is devoid of a chip forming function).

[0126] Since both of the first and second chip surfaces 38A, 38B in this example are mirror-symmetric about the length plane P.sub.L some features below are described with reference to only one of the chip surfaces but should be understood to apply to both.

[0127] Drawing particular attention to FIG. 3A, the second chip surface 38B can comprise a first rear chip edge 38B 1. Along a direction parallel with the length axis A.sub.L, there is defined a second cutting depth L.sub.C2 from the third sub-edge 34C to the second rear chip edge 38B1. In a direction parallel with the thickness axis the second chip surface 38B extends from the second sub-edge 34B to the start of the ridge 36. The ridge 36 is defined as starting at an upwardly extending part of the upper surface (in this case, the start of the upwardly extending part is the start 37B 1 of the second concave side portion 37B, illustrated by an imaginary curvature line in FIG. 3A).

[0128] A general cutting depth L.sub.GC is defined as the smaller of the first and second cutting depths L.sub.C1, L.sub.C2. In this case, the first and second cutting depths L.sub.C1, L.sub.C2 are equal and hence the general cutting depth L.sub.GC is equal to both of them.

[0129] In a view along the downward direction (FIG. 3A), both of first and second chip surfaces 38A, 38B can have a tapering shape wider adjacent to the third sub-edge 34C than at another position spaced further apart therefrom (see, e.g., first and second widths L.sub.W1, L.sub.W2, where the first width L.sub.W1 is nearer to the third sub-edge 34C and is greater in magnitude than the second width L.sub.W2). A chip taper angle 3 can preferably be 4°±2°. Such tapering can be advantageous in destabilization of workpiece chips, by causing different portions thereof to deflect in different directions (intended to cause chip breakage at a desired length).

[0130] Referring now particularly to FIG. 3D, the first and second chip surfaces 38A, 38B can each form a side angle α, which this example is 8°.

[0131] In the same rearward view, a width L.sub.R of the ridge, measurable between ridge extremity points 42A, 42B (which in this case correspond with the same position along the thickness axis as the starting points of the first and second concave portions at the third sub-edge) is less than half an overall insert thickness L.sub.1.

[0132] Reverting to FIG. 3A, the ridge 36 can comprise a ridge front end 36A, a ridge rear end 36B and an intermediary portion 36C extending therebetween.

[0133] The ridge front end 36A can comprise a concave front portion 36A1, a front first planar portion 36A2, and a front second planar portion 36A3 connecting the concave front portion 36A1 and the front second planar portion 36A2.

[0134] An upper rear surface 36B 1 of the ridge rear end 36B can be planar shaped.

[0135] At least an upper surface 36C1 of the intermediary portion 36C can be connected between the front second planar portion 36A3 and the upper rear surface 36B 1.

[0136] As understood best from the view in FIG. 3C, the ridge rear end 36B can extend in both the downward and rearward directions.

[0137] As best shown in FIG. 3F, at least the frontmost portion of the ridge front end 36A (e.g. a ridge discontinuity point 36A4 at which the concave front portion 36A1 and the intermediary plateau 40 meet) of the ridge 36 can extend in the upward and rearward directions D.sub.U, D.sub.R. Accordingly, shown by the full ridge 36 in FIG. 3C, the ridge 36 can have a basic convex shape. Such shape can be advantageous in destabilization of workpiece chips, by causing different portions thereof to deflect in different directions (intended to cause chip breakage at a desired length).

[0138] Referring now to FIG. 3F, while it may be advantageous for machining in the side directions for the front edge of the ridge to extend until the third sub-edge (thereby extending more alongside the main cutting sub-edges of the cutting edge, i.e. the first and second sub-edges), the ridge front end 36A is recessed in this view. This provides an advantage for machining in an axial direction (i.e. in the forward direction D.sub.F) in particular for ductile materials. Even though machining in the side directions constitutes the overwhelming majority of machining, it was found that such feature did not significantly detriment performance. To elaborate, a front spacing length L.sub.FS between the third sub-edge 34C and the start of the ridge front end (i.e. in this example the ridge discontinuity point 36A4) of a ridge, measurable along the insert length axis, can be at least 5% of a general cutting depth L.sub.GC (FIG. 3A).

[0139] Referring now to FIG. 3C, in order to achieve both the ridge's 36 destabilization effect, together with the normal deflection function alongside most of the main cutting edge 22A (i.e. alongside the first and second sub-edges), the ridge rear end 36B can descend only close to a reach chip edge. To elaborate a rear spacing length L.sub.RS between where the ridge rear end 36B2 starts, and a rear edge plane P.sub.RE is at least 5% of the general cutting depth L.sub.GC. As seen from FIGS. 3A and 3C, this rear edge plane P.sub.RE is parallel to the height plane (P.sub.H) and is spaced apart from the third sub-edge 34C by said general cutting depth (L.sub.GC).

[0140] Directing attention to FIGS. 2A to 2C, a tool 14 is shown. The tool 14 comprises front and rear tool ends 44A, 44B and an elongated body 44C extending therebetween. To elaborate, the tool 14 can have tool front and rear surfaces 46A, 46B first, second, third and fourth tool sides surfaces 46C, 46D, 46E, 46F extending at right angles to each other and between the tool front and rear surfaces 46A, 46B.

[0141] The tool 14 also defines tool upward, downward, first side, second side, forward and rearward directions D.sub.TU, D.sub.TD, D.sub.TS1, D.sub.TS2, D.sub.TF, D.sub.TR.

[0142] The tool can comprise a single insert seat 48 at the front tool end 44A. More precisely the insert seat 48 can be formed at an intersection of the tool front surface 46A and first and second tool side surfaces 46C, 46D.

[0143] The insert seat 48 can comprise a tool first abutment surface 48A and at least one internally threaded tool bore 50 formed therein.

[0144] The tool first abutment surface 48A can extend parallel, or substantially parallel, with the second tool side surface 46D. The tool first abutment surface 48A, or at least portions thereof, can be planar shaped for precise mounting of an insert 12.

[0145] The insert seat 48 can further comprise tool second and third abutment surfaces 48B, 48C separated by a relief recess 48D, all of which extend along a periphery of the tool first abutment surface.

[0146] The tool second abutment surface 48B can extend in the tool rearward direction D.sub.TR from the tool front surface 46A. As shown in FIG. 2B, the tool second abutment surface 48B is also inwardly slanted, i.e. extending in the tool downward and second side directions D.sub.TD, D.sub.TS2 to assist in securely clamping the insert 12 against the tool 14.

[0147] The tool third abutment surface 48C can also be slanted for better clamping. As shown it can extend in the tool rearward, second side and downward directions D.sub.TR, D.sub.TS2 D.sub.TD.

[0148] Stated differently, each of the following pairs of surfaces are mutually inclined: the tool first abutment surface 48A and the insert's second side surface 24B (or more precisely, the bearing configuration's 30 bearing surface 30A); the tool second abutment surface 48B and the insert lower surface 26B (or more precisely, the lower abutment portion 26B3 thereof); and the tool third abutment surface 48C and the insert rear surface 28B (or more precisely, the rear abutment portion 28B 1 thereof).

[0149] Directing attention to FIG. 1A to 1C, the insert 12 is shown in a clamped position in the insert seat 48, with all clamping contact between the insert and tool being by the following surfaces: the tool first abutment surface 48A and the insert's second side surface 24B (or more precisely, the bearing configuration's 30 bearing surface 30A); the tool second abutment surface 48B and the insert lower surface 26B (or more precisely, the lower abutment portion 26B3 thereof); and the tool third abutment surface 48C and the insert rear surface 28B (or more precisely, the rear abutment portion 28B1 thereof). The clamping further includes a clamping force, provided in this example by the screw 16.

[0150] For swiss machining, it will be noted from the view of FIG. 1B that the first corner edge 34D is preferably aligned with both the first and second tool side surfaces 46C, 46D.

[0151] Similarly, the first sub-edge 34A can be aligned with the common edge of the tool second side surface 46D in both FIGS. 1A and 1B.

[0152] Referring to FIG. 4, a metal workpiece 52 is shown clamped in a typical manner for swiss-style CNC machines (not shown). Notably, the workpiece 52 is held by a bushing 54 adjacent to a portion 56 of the workpiece 52 being machined, with an end 58 of the workpiece 52 being unsecured.

[0153] It will be understood that the first cutting edge 20A and chip former arrangement 22A according to the present application allow machining in both first and second side directions D.sub.S1, D.sub.S2 shown as well as in an axial direction (i.e. the forward direction D.sub.F, D.sub.TF).

[0154] FIGS. 5A and 5B are shown to demonstrate a typical gang 60 of four swiss tool assemblies 10 (i.e. a tool assembly 10 comprising an insert 12 and a tool 14). It will be understood from the closely packed arrangement why inserts 12 of other types are not useable in such gangs 60.