A cutting insert includes a split cutting edge, formed at an intersection of the insert forward surface and the insert upper surface, the split cutting edge includes an axially leading cutting edge and an axially trailing cutting edge. An undercut is located in the insert forward surface and interrupts the split cutting edge at an undercut edge portion that extends between the leading and trailing cutting edges. The undercut edge portion transitions into the axially trailing cutting edge at a straight trailing cutting edge portion of the trailing cutting edge.

A tool for chip-removing machining including a tool body and at least one cutting insert mounted in an insert seat of the tool body. The cutting insert includes an upper side and a lower side directed toward a bottom contact surface of the insert seat. The cutting insert is formed by sintering together two compacted powder parts, one of the parts forming an upper part and the other forming a lower part. An imaginary plane is defined between the lower and upper parts. A side surface extends between the upper and lower sides around the periphery of the cutting insert, and at least one cutting edge is formed in a transition between the upper side and the side surface. The tool is configured so that the tool body contacts the side surface of the cutting insert only above the imaginary plane along an upper part of the side surface.

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

A cutting insert for a tool for machining a workpiece, wherein the cutting insert has a 180 rotational symmetry about a bore axis extending perpendicularly and centrally through two opposing, identical base surfaces of the cutting insert, and has two identical parts which are connected along a center plane, wherein said center plane extends orthogonally to the bore axis and has the same distance from each of the two base surfaces, wherein each part has two identical mutually opposite main sides and two identical mutually opposite secondary sides, wherein each main side has a rectilinear main cutting edge extending parallel to the center plane, and each secondary side has a planar bearing surface extending orthogonally to the center plane, wherein the two main cutting edges of each part extend parallel to one another and transversely to the two main cutting edges of the respective other part, and wherein the two main cutting edges of each part extend parallel to the two bearing surfaces of the respective other part, wherein each main cutting edge transitions at its respective first end into a first segmental cutting edge which is arranged on a first protrusion provided on an adjacent secondary side of the respective part, and wherein each main cutting edge transitions into a second segmental cutting edge at its respective second end, opposite the first end, which is arranged on a second protrusion provided on the respective other adjacent secondary side of the respective part, wherein the first and the second protrusions each adjoin the bearing surface arranged on the respective same secondary side and project with respect to the respective bearing surface.

A turning tool holder includes a tool body, a cutting tool insert, and a shim. A coolant conduit system extends through the turning tool holder, a first portion of the coolant conduit system extending through the tool body and an end portion of the coolant conduit system extending through the shim. The end portion of the coolant conduit system includes a through hole extending from a first surface to an opposite second surface of the shim. The end portion has a coolant outlet opening at the second surface, the coolant outlet opening being formed by the shim alone. A jet of coolant from the coolant outlet opening may be directed towards a space expected to have a cutting zone of a workpiece. Further a cutting tool insert arranged to be used in a turning tool holder is disclosed.

A cutting insert for a tool for machining a workpiece, wherein the cutting insert has a 180 rotational symmetry about a bore axis extending perpendicularly and centrally through two opposing, identical base surfaces of the cutting insert, and has two identical parts which are connected along a center plane, wherein said center plane extends orthogonally to the bore axis and has the same distance from each of the two base surfaces, wherein each part has two identical mutually opposite main sides and two identical mutually opposite secondary sides, wherein each main side has a rectilinear main cutting edge extending parallel to the center plane, and each secondary side has a planar bearing surface extending orthogonally to the center plane, wherein the two main cutting edges of each part extend parallel to one another and transversely to the two main cutting edges of the respective other part, and wherein the two main cutting edges of each part extend parallel to the two bearing surfaces of the respective other part, wherein each main cutting edge transitions at its respective first end into a first segmental cutting edge which is arranged on a first protrusion provided on an adjacent secondary side of the respective part, and wherein each main cutting edge transitions into a second segmental cutting edge at its respective second end, opposite the first end, which is arranged on a second protrusion provided on the respective other adjacent secondary side of the respective part, wherein the first and the second protrusions each adjoin the bearing surface arranged on the respective same secondary side and project with respect to the respective bearing surface.

A cutting insert for a tool for machining a workpiece, wherein the cutting insert has a 180 rotational symmetry about a bore axis extending perpendicularly and centrally through two opposing, identical base surfaces of the cutting insert, and has two identical parts which are connected along a center plane, wherein said center plane extends orthogonally to the bore axis and has the same distance from each of the two base surfaces, wherein each part has two identical mutually opposite main sides and two identical mutually opposite secondary sides, wherein each main side has a rectilinear main cutting edge extending parallel to the center plane, and each secondary side has a planar bearing surface extending orthogonally to the center plane, wherein the two main cutting edges of each part extend parallel to one another and transversely to the two main cutting edges of the respective other part, and wherein the two main cutting edges of each part extend parallel to the two bearing surfaces of the respective other part, wherein each main cutting edge transitions at its respective first end into a first segmental cutting edge which is arranged on a first protrusion provided on an adjacent secondary side of the respective part, and wherein each main cutting edge transitions into a second segmental cutting edge at its respective second end, opposite the first end, which is arranged on a second protrusion provided on the respective other adjacent secondary side of the respective part, wherein the first and the second protrusions each adjoin the bearing surface arranged on the respective same secondary side and project with respect to the respective bearing surface.

A double-sided cutting insert for a drilling tool includes a top side, a bottom side, and at least one side surface interconnecting the top side and the bottom side and forming at least one cutting edge. The top side and the bottom side comprise a different external profile and chip groove geometry and an identical inscribed circle, and each of the top side and the bottom side comprises four indexable cutting edges.

Cutting insert with a cuboid body has a substantially square top face and bottom face, said top face and bottom face connected by four peripheral adjoining side surfaces. At least two cutting edges are formed at the transition of the top face to at least two side surfaces, that cutting edges defining a plane of the top face. To provide a cutting insert and a corresponding tool suited to produce valve seat surfaces with high precision but still having a rather simple construction and being precisely mountable with ease and less efforts of adjustment, the plane defined by the top face cutting edges of the cutting insert has maximum dimensions of 7 mm7 mm, where the bottom face has a supporting surface formed exactly parallel to the plane defined by the top face cutting edges by means of grinding within a tolerance of less than 5 angular minutes.