Cutting insert for right-angle milling, milling tool and manufacture method thereof

Abstract

The present disclosure relates to a cutting insert specifically designed for right-angle milling having a threefold rotational symmetry, along with a complementary milling tool. The cutting insert presents novel features enhancing its efficiency and precision during milling operations. The milling tool is configured to accommodate and optimize the use of this cutting insert for right-angle milling purposes. Various uses and a manufacture method for the cutting insert is detailed.

Description

D E S C R I P T I O NCUTTING INSERT FOR RIGHT-ANGLE MILLING, MILLING TOOL AND MANUFACTURE METHOD THEREOFTECHNICAL FIELD

[0001] The present disclosure relates to a cutting insert for milling and respective milling tool, also respective uses and manufacture method thereof. The present disclosure includes a cutting insert for right-angle (or 90°) milling and complementary milling tool.BACKGROUND

[0002] Milling with rotary cutting tools, having cutting inserts mounted thereupon, is used to remove material from a workpiece. Cutting inserts are replaceable cutting tips mounted on the rotary milling tool. These inserts can have various shapes, materials, and cutting geometries tailored to specific materials and applications.

[0003] During milling, the cutting tool rotates, and the respective cutting inserts rotate around the cutting tool axis and thus turn around relative to the workpiece. This movement allows the inserts to cut and shape the workpiece into the desired shape. The milling process can create various shapes, grooves, contours, and holes on the surface of the workpiece.

[0004] Milling with cutting inserts offers advantages such as high precision, repeatability, and the ability to work with a wide range of materials, including metals, plastics, and composites. The different types of milling operations include face milling, shoulder milling and profile milling, each of which is suited to specific machining needs.

[0005] The document KR101240880B1 discloses an indexable milling insert and a milling tool for chip removing machining. The milling insert is intended to be able to mill substantially perpendicular corners in a work piece. The milling insert comprises an upper side, a lower side and edge surfaces extending there between. The upperside and the lower side are substantially identical. An imaginary circle inscribed in the milling insert touches the milling insert periphery in four to six points. Lines of intersection between the edge surfaces and the sides form relative to each other substantially perpendicular main cutting edges and minor cutting edges. Each of the side includes a support surface, each of which being provided in a plane. Each minor cutting-edge projects from the plane of the associated support surface. Each major cutting edge intersects the plane of the associated support surface.

[0006] The document US10464146B2 discloses a cutting insert according to an embodiment of the present invention, an upper cutting edge includes, sequentially from a first corner to a second corner, a corner cutting edge, a minor cutting edge inclined as separating from the corner cutting edge at a first inclination angle on a basis of a vertical plane perpendicular to a central axis extending between upper and lower surfaces, and a major cutting edge inclined as separating from the minor cutting edge at a second inclination angle on the basis of the vertical plane so as to become more closer to the lower surface than the minor cutting edge. A cross section of a rake surface obtained by cutting an inwardly located end portion thereof along a direction of the central axis has a straight-line shape or concave shape in a region crossing over at least a minor rake surface and a major rake surface. A cutting tool with the cutting insert, and a method of manufacturing a machined product by using the cutting tool are also provided.

[0007] The document US9724769B2 discloses a cutting insert is suitable for right-angle shoulder milling. The cutting insert includes two end surfaces: first and second end surfaces; a peripheral side surface extending therebetween; and a cutting edge formed at an intersecting ridge portion between the first end surface and the peripheral side surface. The cutting edge is formed so that the first end surface functions as a rake face and a part of the peripheral side surface functions as a flank. A side surface portion of the peripheral side surface adjacent to at least a part of the cutting edge includes a first flank portion adjacent to the cutting edge, a second flank portion, a third flank portion, and a fourth flank portion in this order from the first end surface side toward the second end surface side.

[0008] These documents disclose cutting inserts where a relatively high number of edges on the insert are possible, namely documents KR101240880B1 and US10464146B2, however these are not able to define the same cutting angles or have insufficiencies in the clamping stability. Thus, existing inserts with positive cutting angle have fewer working edges or, conversely, existing inserts with the same number of working edges do not provide a positive cutting angle. There is thus a need for a cutting insert for milling operations with a relatively high number of working edges, positive cutting angle and clamping stability.

[0009] These facts are disclosed in order to illustrate the technical problem addressed by the present disclosure.GENERAL DESCRIPTION

[0010] It is disclosed a cutting insert for milling and respective milling tool, also respective uses and operation method thereof.

[0011] The present disclosure relates to a cutting insert specifically designed for rightangle milling having a threefold rotational symmetry, along with a complementary milling tool. The cutting insert presents novel features enhancing its efficiency and precision during milling operations. The milling tool is configured to accommodate and optimize the use of this cutting insert for right-angle milling purposes. Various uses and an operational method for both the cutting insert and milling tool are detailed herein.

[0012] The disclosed cutting insert is useful for cutting a right-angle lateral wall with a positive cutting angle and with 6 usable cutting edges, among other benefits as discussed below. Right-angle milling may refer to milling a 90° angle within work tolerance or milling approximately a 90° angle depending on, for example, the intended application, metal type, or desired cutting profile.

[0013] In particular, the disclosed cutting insert is advantageous for slotting, peripheral or shoulder milling, linear or circular entry-ramp milling, among others. Also, the disclosed cutting insert is advantageous for roughing, medium milling, medium finishing, or finishing, and is particularly advantageous for roughing, medium milling and medium finishing.

[0014] Higher milling rates typically result in more significant forces and heat generation, leading to accelerated wear on the cutting insert. The disclosed insert has the advantage of providing a more positive cutting configuration which enables cutting with less heat being generated and the insert undergoing less wear, also allowing higher milling rates.

[0015] In particular, milling stainless steel generates even more heat than when milling other materials, which makes the disclosed cutting insert particularly useful for 90° milling of stainless steel.

[0016] An aspect of the present disclosure relates to a cutting insert for a milling tool for right-angle milling, having a threefold rotational symmetry, i.e. the cutting insert looks the same when rotated by 120 degrees around its axis, comprising: a first end surface; a second end surface opposite to the first end surface; a lateral surface extending between said first and second surfaces; a first cutting edge extending along an intersection between the first surface and the lateral surface; a second cutting edge extending along an intersection between the second surface and the lateral surface; and a clearance surface defined in said lateral surface; wherein said first and second surfaces are perpendicular to a centre axis of the cutting insert about which said threefold rotational symmetry is centred; wherein at least one of the cutting edges comprises a corner region with a primary cutting edge, a corner cutting edge, and a secondary cutting edge; wherein the primary cutting edge is arranged for radial cutting and the secondary cutting edge is arranged for axial cutting; wherein the clearance surface comprises a first subsurface and a second subsurface, said first subsurface adjoining the secondary cutting edge; i.e. the clearance surface extends from the primary cutting edge; and the second subsurface adjoining the first subsurface; i.e. the second subsurface, extends from first subsurface which extends from the primary cutting edge;wherein the primary cutting edge and adjoining surfaces; i.e. the adjoining clearance surface or surfaces; are arranged for a positive radial rake angle (Rl°) and a positive relief angle (C°, D°), and the secondary cutting edge and adjoining surfaces; i.e. the adjoining clearance surface or surfaces; are arranged for a positive axial rake angle (R2°) and a positive relief angle (A°, B°); wherein the second subsurface is recessed in respect of the first surface; i.e. the recess is inwardly recessed (a) into the cutting insert to provide a more positive radial rake angle.

[0017] An aspect of the present disclosure relates to Cutting insert (1) for a milling tool (15) for right-angle milling, having a threefold rotational symmetry, comprising: a first end surface (13); a second end surface opposite to the first end surface; a lateral surface (3) extending between said first and second surfaces; a first cutting edge extending along an intersection between the first surface and the lateral surface; a second cutting edge extending along an intersection between the second surface and the lateral surface; a clearance surface (8) defined in said lateral surface (3); and a mounting hole (2) for mounting the cutting insert (1) on a milling tool (15); wherein said first and second surfaces are perpendicular to a centre axis of the cutting insert about which said threefold rotational symmetry is centred; wherein the first cutting edge comprises a first corner region arranged on the first end surface (13), and the second cutting edge comprises a second corner region arranged on the second end surface, wherein the first corner region is opposite the second corner region, wherein each corner region comprises a primary cutting edge (4b), a corner cutting edge (7), and a secondary cutting edge (4a); wherein the primary cutting edge (4b) is arranged for radial cutting and the secondary cutting edge (4a) is arranged for axial cutting; wherein the clearance surface (8) comprises, for each corner region, a first subsurface (8a) and a second subsurface (8b), said first subsurface (8a) adjoiningthe respective secondary cutting edge (4a) and the second subsurface (8b) adjoining the first subsurface (8a); wherein, when the cutting insert (1) is mounted on the milling tool (15) by the mounting hole (2), the primary cutting edge (4b) and adjoining surfaces of the primary cutting edge (4b) are arranged for a positive radial rake angle (Rl°) and a positive relief angle (C°, D°), and the secondary cutting edge (4a) and adjoining surfaces of the secondary cutting edge (4a) are arranged for a positive axial rake angle (R2°) and a positive relief angle (A°, B°); wherein the second subsurface (8b) is recessed (a) in respect of the first surface (8a), wherein said recess defines a recess edge (8c) between the first subsurface (8a) and the second subsurface (8b); wherein the first corner region and the second region are slanted in respect of a milling direction defined by said end surfaces [i.e. a line joining the corner cutting edges of the first and second corner regions is an inclined line in respect of said end surfaces, thus a line not perpendicular to said end surfaces, or not parallel to an axis defined by the mounting hole (2)]; wherein a recess edge (8c) of the first corner region and a recess edge (8c) of the second corner region are connected by a connecting edge (8d) which defines a slanted path in respect of said end surfaces [i.e. inclined in respect of said end surfaces, thus not perpendicular to said end surfaces],

[0018] ]ln an embodiment, the cutting instrument of the present disclosure may comprises a support surface (9) defined in said lateral surface (3) and adjoining the primary cutting edge (4b), and arranged to provide clearance for the primary cutting edge (4b), wherein a cross-section going from the primary cutting edge (4b) of the first corner region, by the support surface (9) of the first corner region, by the second subsurface (8b) of the second corner region, and by the first subsurface (8a) of the second corner region, to the secondary cutting edge (4a) of the second corner region, defines an asymmetric recess comprising a sloped surface at the support surface (9) and at the second subsurface (8b), and comprising a recessed edge (8c)between the first subsurface (8a) and the second subsurface (8b) [and vice-versa, i.e. the first and second corner regions reversed],

[0019] In an embodiment for better results, the cutting insert may comprise a support surface, i.e. not comprising a recessed surface such that the primary cutting edge (4b) is suitable for supporting the primary cutting edge (4b), defined in said lateral surface and adjoining the primary cutting edge, and arranged to provide clearance for the primary cutting edge.

[0020] In an embodiment for better results, said support surface is angled in respect of the primary cutting edge to provide a positive radial rake angle (C°, D°).

[0021] In an embodiment for better results, the first subsurface has a cross-section along a radial advancement direction defining a first relief angle (A°) of the first subsurface, and the second subsurface has a cross-section along a radial advancement direction defining a second relief angle (B°) which is larger than the first relief angle (A°).

[0022] In an embodiment for better results, the primary cutting edge, the corner cutting edge, and the secondary cutting edge form an uninterrupted cutting edge.

[0023] In an embodiment for better results, the secondary cutting edge and adjoining surfaces are arranged for surface-wiping.

[0024] In an embodiment for better results, the primary cutting edge, the corner cutting edge, and the secondary cutting edge are raised in respect of a respective end surface.

[0025] In an embodiment for better results, the primary cutting edge gradually rises (H°), in respect of a respective end surface, as it approaches the corner cutting edge.

[0026] In an embodiment for better results, the secondary cutting edge is substantially parallel to a respective end surface.

[0027] In an embodiment for better results, the length of primary cutting edge is longer than the length of the secondary cutting edge.

[0028] In an embodiment for better results, said recess defines a recess edge between the first subsurface and the second subsurface.

[0029] In an embodiment for better results, the first cutting edge comprises a first corner region arranged on the first end surface and the second cutting edge comprise a second corner regions arranged on the second end surface, wherein the first corner region is opposite the second corner region.

[0030] In an embodiment for better results, the first cutting edge comprises three corner regions arranged on the first end surface and the second cutting edge comprises three corner regions arranged on the second end surface, wherein each of the corner region of the first cutting edge is opposite to a respective corner region of the second cutting edge.

[0031] In an embodiment for better results, the cutting insert may comprise a first recess edge of a first corner region and a second recess edge of a second corner region, said second corner region being opposite to the first corner region, are connected by a connecting edge which defines a slanted path in respect of said end surfaces.

[0032] In an embodiment for better results, the connecting edge (8d) is step-wise slanted; i.e. the edge changes direction abruptly at specific points to provide an overall slanted line; or smoothly slanted; i.e. the edge is continuously slanted, that is free of jumps, breaks, or abrupt line changes.

[0033] In an embodiment for better results, the cutting insert has a substantially triangular cross-section.

[0034] In an embodiment for better results, the cutting insert may comprise a rake face of the primary cutting edge, which has an inward rake angle Rl° in respect of the first end surface.

[0035] In an embodiment for better results, the cutting insert may comprise a chip discharge surface of the primary cutting edge adjoining said rake face of the primary cutting edge.

[0036] In an embodiment for better results, the cutting insert may comprise a rake face of the secondary cutting edge, which has an inward rake angle R2° in respect of the first end surface.

[0037] In an embodiment for better results, the cutting insert may comprise a chip discharge surface of the secondary cutting edge, adjoining said rake face of the secondary cutting edge.

[0038] In an embodiment for better results, the cutting insert may comprise a rake face of the corner cutting edge, which has an inward rake angle in respect of the first end surface.

[0039] In an embodiment for better results, the cutting insert may comprise a chip discharge surface of the corner cutting edge, adjoining said rake face of the corner cutting edge.

[0040] Another aspect of the present disclosure relates to a milling tool comprising a matching recess for receiving one or more of the cutting insert of the present disclosure arranged for a positive radial rake angle and for a positive axial rake angle.

[0041] Another aspect of the present disclosure relates to a cutting insert kit for shoulder or 90° milling comprising the milling tool of the present disclosure and one or more of the cutting insert of the present disclosure.

[0042] Manufacture method for obtaining the cutting insert of the present disclosure, comprising forming a cutting insert of a compressed powder comprising said edges and surfaces, and sintering said formed cutting insert, in particular the powder being a tungsten-based powder or a cobalt-based powder, further in particular the powder being a tungsten carbide powder.BRIEF DESCRIPTION OF THE DRAWINGS

[0043] The following figures provide preferred embodiments for illustrating the disclosure and should not be seen as limiting the scope of invention.

[0044] Figure 1: Schematic representation which shows a perspective view of a cutting insert according to an embodiment of the invention.

[0045] Figure 2: Schematic representation of the top view of a cutting insert and section views along the line J-J, G-G and E-E, according to an embodiment of the invention.

[0046] Figure 3A: Show insert top view, right side view, sections views along the line L- L and M-M, and the corresponding detail views O, Q and P, according to an embodiment of the invention.

[0047] Figure 3B: Schematic representation of insert edge contact point to the peripherical, machined plane and section views along the line A-A and B-B, according to an embodiment of the invention. Detail E with edge relief angles on machined plane and detail F with edge relief angles on the side machined plane.

[0048] Figure 4: Schematic representation of a perspective view of a shoulder milling tool according to an embodiment of the invention, detail A from the perspective view of fig. 4.

[0049] Figure 5: Schematic representation of a perspective exploded view of a shoulder milling tool according to an embodiment of the invention, detail A from the perspective view of figure 5 with insert pocket of the cutting tool shown in figure 4 and 5.

[0050] Figure 6: Schematic representation of front view of a shoulder milling tool according to an embodiment of the invention with a portion of the machined parts, section views along the line H-H and l-l.DETAILED DESCRIPTION

[0051] The disclosed cutting insert for milling and respective milling tool are useful for cutting a right-angle lateral wall with a positive cutting angle and enabling 6 usable corner region cutting edges, among other benefits. In particular, the disclosed cutting insert is advantageous for slotting, peripheral or shoulder milling, linear or circular entry-ramp milling, among others.

[0052] The proposed geometry besides the ability to be used with advantageous positive cutting angles, allowing less cutting effort and providing double-sided cutting faces with more cutting edges, also allows for improved clamping.

[0053] Figure 1 illustrates a schematic representation showing a perspective view of a cutting insert according to an embodiment of the invention.

[0054] Figure 2 shows a schematic representation of the top view of a cutting insert and section views along the line J-J, G-G and E-E.

[0055] Figure 3A shows an insert top view, right side view, sections views along the line L-L and M-M, and the corresponding detail views O, Q and P.

[0056] Figure 3B illustrates a schematic representation of insert edge contact point to the peripherical, machined plane and section views along the line A-A and B-B. Detail E with edge relief angles on machined plane and detail F with edge relief angles on the side machined plane.

[0057] Figure 4 shows a schematic representation of a perspective view of a shoulder milling tool according to an embodiment of the invention, detail A from the perspective view of fig. 4.

[0058] Figure 5 shows a schematic representation of a perspective exploded view of a shoulder milling tool according to an embodiment of the invention, detail A from the perspective view of figure 5 with insert pocket of the cutting tool shown in figure 4 and 5.

[0059] Figure 6 shows a schematic representation of front view of a shoulder milling tool according to an embodiment of the invention with a portion of the machined parts, section views along the line H-H and l-l.

[0060] The following features are illustrated in the attached drawings with the respective reference numbers:1 represents a cutting insert according to an embodiment of the invention2 represents a mounting hole of the cutting insert 13 represents a lateral surface of the cutting insert 14a represents a secondary cutting edge4b represents a primary cutting edge6 represents a rake face of the primary cutting edge 4b6a represents a chip discharge surface of the primary cutting edge 4b7 represents a corner cutting edge7a represents a corner lateral surface8 represents a clearance surface of the secondary cutting edge 4a8a represents a first subsurface of the clearance surface 88b represents a second subsurface of the clearance surface 88c represents a recess edge between adjacent first subsurface 8a and second subsurface 8b8d represents a connecting edge which connects a first recess edge (8c) of a first corner region with a second recess edge (8c) of a second corner region which is opposite to the first corner region9 represents a clearance and support surface of the primary cutting edge 4b10 represents a rake face of the secondary cutting edge 4a10a represents a chip discharge surface of the secondary cutting edge 4a11 represents a transition surface between the clearance surface of a secondary cutting edge 4a, and the clearance and support surface of a primary cutting edge 4b belonging to different corner regions of the cutting insert 112 represents a transition edge between a secondary cutting edge 4a and a primary cutting edge 4b belonging to different corner regions of the cutting insert113 represents an end surface of the cutting insert 114 represents a corner rake face of the corner cutting edge 714a represents a corner chip discharge surface of the corner cutting edge 715 represents a milling tool for receiving insert 116 represents a mounting screw18 represents matching recesses of the milling tool for receiving corresponding features of the cutting insert19 represents a mounting hole of the milling tool for receiving the mounting screw A-A represents a cross-section of schematic representation of insert edge contact point to the periphericalB-B represents a cross-section of schematic representation of insert edge contact point to machined planeE-E represents a cross-section of insert top view where the second edge is detailed G-G represents a cross-section of the insert top view where the primary edge is detailedJ-J represents a cross-section of insert top view where the hole insert is detailedL-L represents a cross-section of insert top view where the second edge is detailed M-M represents a cross-section of insert top view where the primary edge is detailedN-N represents a cross-section of insert top view where the hole insert is detailed A represents a magnified detail view of schematic representation of a perspective view of a shoulder milling tool where screw and insert are detailedB represents a magnified detail view of schematic representation of a perspective view of a shoulder milling tool where insert pocket is detailedE represents a magnified detail view of the insert section view along the line B-B where with secondary edge relief angles on machined planeF represents a magnified detail view of the insert section view along the line A-A where with primary edge relief angles on machined planeO represents a magnified detail view of the insert section view along the line M-M where with primary edge relief angles on machined planeP represents a magnified detail view of the insert section view along the line P-P where with primary edge relief angles on machined planeQ represents a magnified detail view of the primary edge where helix angle is detailedA°, B° represent positive axial rake anglesC°, D° represent positive radial rake anglesRl° represents an angle of the rake face 6 of the primary cutting edge 4b in respect of a respective end surfaceR2° represents an angle of the rake face 10 of the secondary cutting edge 4a in respect of a respective end surfaceH° represents an angle of the primary cutting edge (4b) as it gradually rises (H°), in respect of a respective end surface (13), towards the corner cutting edge (7)

[0061] The term "comprising" whenever used in this document is intended to indicate the presence of stated features, integers, steps, components, but not to preclude the presence or addition of one or more other features, integers, steps, components, or groups thereof.

[0062] The disclosure should not be seen in any way restricted to the embodiments described and a person with ordinary skill in the art will foresee many possibilities to modifications thereof. The above-described embodiments are combinable.

[0063] The following claims further set out particular embodiments of the disclosure.

Claims

C L A I M S1. Cutting insert (1) for a milling tool (15) for right-angle milling, having a threefold rotational symmetry, comprising: a first end surface (13); a second end surface opposite to the first end surface; a lateral surface (3) extending between said first and second surfaces; a first cutting edge extending along an intersection between the first surface and the lateral surface; a second cutting edge extending along an intersection between the second surface and the lateral surface; a clearance surface (8) defined in said lateral surface (3); and a mounting hole (2) for mounting the cutting insert (1) on a milling tool (15); wherein said first and second surfaces are perpendicular to a centre axis of the cutting insert about which said threefold rotational symmetry is centred; wherein the first cutting edge comprises a first corner region arranged on the first end surface (13), and the second cutting edge comprises a second corner region arranged on the second end surface, wherein the first corner region is opposite the second corner region, wherein each corner region comprises a primary cutting edge (4b), a corner cutting edge (7), and a secondary cutting edge (4a); wherein the primary cutting edge (4b) is arranged for radial cutting and the secondary cutting edge (4a) is arranged for axial cutting; wherein the clearance surface (8) comprises, for each corner region, a first subsurface (8a) and a second subsurface (8b), said first subsurface (8a) adjoining the respective secondary cutting edge (4a) and the second subsurface (8b) adjoining the first subsurface (8a); wherein, when the cutting insert (1) is mounted on the milling tool (15) by the mounting hole (2), the primary cutting edge (4b) and adjoining surfaces of the primary cutting edge (4b) are arranged for a positive radial rake angle (Rl°) and a positive relief angle (C°, D°), and the secondary cutting edge (4a) and adjoiningsurfaces of the secondary cutting edge (4a) are arranged for a positive axial rake angle (R2°) and a positive relief angle (A°, B°); wherein the second subsurface (8b) is recessed (a) in respect of the first surface (8a), wherein said recess defines a recess edge (8c) between the first subsurface (8a) and the second subsurface (8b); wherein the first corner region and the second region are slanted in respect of a milling direction defined by said end surfaces; wherein a recess edge (8c) of the first corner region and a recess edge (8c) of the second corner region are connected by a connecting edge (8d) which defines a slanted path in respect of said end surfaces.

2. Cutting insert (1) according to the previous claim comprising a support surface (9) defined in said lateral surface (3) and adjoining the primary cutting edge (4b), and arranged to provide clearance for the primary cutting edge (4b), wherein a cross-section going from the primary cutting edge (4b) of the first corner region, by the support surface (9) of the first corner region, by the second subsurface (8b) of the second corner region, and by the first subsurface (8a) of the second corner region, to the secondary cutting edge (4a) of the second corner region, defines an asymmetric recess comprising a sloped surface at the support surface (9) and at the second subsurface (8b), and comprising a recessed edge (8c) between the first subsurface (8a) and the second subsurface (8b).

3. Cutting insert (1) according to the previous claim wherein said support surface (9) is angled in respect of the primary cutting edge (4b) to provide a positive radial rake angle (C°, D°).

4. Cutting insert (1) according to any of the previous claims wherein the first subsurface (8a) comprises a cross-section along a radial advancement direction defining a first relief angle (A°) of the first subsurface (8a), and the second subsurface (8b) comprises a cross-section along a radial advancement direction defining a second relief angle (B°) which is larger than the first relief angle (A°).

5. Cutting insert (1) according to any of the previous claims wherein the primary cutting edge (4b), the corner cutting edge (7), and the secondary cutting edge (4a) form an uninterrupted cutting edge.

6. Cutting insert (1) according to any of the previous claims wherein the secondary cutting edge (4a) and adjoining surfaces are arranged for surface-wiping; preferably wherein the secondary cutting edge (4a) is substantially parallel to a respective end surface (13).

7. Cutting insert (1) according to any of the previous claims wherein the primary cutting edge (4b), the corner cutting edge (7), and the secondary cutting edge (4a) are raised in respect of a respective end surface (13) and / or wherein the primary cutting edge (4b) gradually rises (H°), in respect of a respective end surface (13), as it approaches the corner cutting edge (7).

8. Cutting insert (1) according to any of the previous claims wherein the length of primary cutting edge (4b) is longer than the length of the secondary cutting edge (4a).

9. Cutting insert (1) according to any of the previous claims wherein the cutting insert has a substantially triangular cross-section.

10. Cutting insert (1) according to any of the previous claims wherein the first cutting edge comprises three corner regions arranged on the first end surface (13) and the second cutting edge comprises three corner regions arranged on the second end surface, wherein each of the corner region of the first cutting edge is opposite to a respective corner region of the second cutting edge.

11. Cutting insert (1) according to the previous claim wherein the connecting edge (8d) is step-wise slanted or smoothly slanted.

12. Cutting insert (1) according to any of the previous claims comprising a rake face (6) of the primary cutting edge (4b), which has an inward rake angle Rl° in respect ofthe first end surface (13); and / or a rake face (10) of the secondary cutting edge (4a), which has an inward rake angle R2° in respect of the first end surface (13); and / or a rake face (14) of the corner cutting edge (7), which has an inward rake angle in respect of the first end surface (13).

13. Cutting insert (1) according to the previous claim comprising a chip discharge surface (6a) of the primary cutting edge (4b) adjoining said rake face (6) of the primary cutting edge (4b); and / or a chip discharge surface (10a) of the secondary cutting edge (4a), adjoining said rake face (10) of the secondary cutting edge (4a); and / or a chip discharge surface (14a) of the corner cutting edge (7), adjoining said rake face (14) of the corner cutting edge (7).

14. Milling tool comprising a matching recess for receiving one or more of the cutting insert of any of the previous claims arranged for a positive radial rake angle and for a positive axial rake angle.

15. Cutting insert kit for shoulder or 90° milling comprising the milling tool of the previous claim and one or more of the cutting insert of any of the claims 1-14.

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