A grooving insert includes a front surface and an opposite rear surface, a first side surface and an opposite second side surface, and a top surface and an opposite bottom surface. The top surface includes a top front portion and a top rear portion, the top front portion having a cutting edge arranged symmetrically relative to a first plane. The bottom surface is symmetrically arranged in relation to a second plane, the first plane and the second plane forming an angle () of 0.5-5.0 relative to each other.

A parting-off insert for relatively high feed includes a rake surface including a reinforced front sub-edge extending between two convex corner sub-edges. A cutting width W.sub.C is defined between distal points of the first and second convex corner sub-edges. The cutting width W.sub.C fulfills the condition: W.sub.C6 mm. The front sub-edge including a minimum front sub-edge thickness T.sub.F fulfilling the condition: T.sub.F>0.20 mm.

A disposable cutting insert locking structure includes a shank and a disposable cutting insert. An insert seat is disposed at a front end of the shank. The insert seat has a positioning portion. The positioning portion has a triangular shape. The positioning portion is provided with a screw hole. The disposable cutting insert has a bottom. The bottom is formed with a positioning recess. A through hole is defined in the positioning recess for a screw to be inserted from a top of the disposable cutting insert and screwed to the insert seat.

The edge portion includes an upper surface, a side surface, and a land surface. The side surface has a front side surface and a pair of lateral side surfaces. An intersection between the land surface and the front side surface forms a front cutting edge. An intersection between the land surface and each of the pair of lateral side surfaces form a corresponding one of a pair of lateral cutting edges. The edge portion contains 80 vol % or more of diamond. A chip breaker recess is provided between the upper surface and the land surface. The surfaces forming the chip breaker recess include a rake face and a breaker wall surface. The upper surface has a front edge portion opposite to the front cutting edge from the chip breaker recess. A pair of protruding portions are provided to extend from the front edge portion toward the front cutting edge.

A turning tool for internal turning of a metal work piece having a rear end, an opposite forward end and a longitudinal center axis extending therebetween. The first nose cutting edge includes a first radially distal point having an associated first rake face and separates and connects a first forward cutting edge and a first rearward cutting edge. A second nose cutting edge of the turning tool includes a second radially distal point having an associated second rake face and separates and connects a second forward cutting edge and a second rearward cutting edge. The second radially distal point is positioned ahead of the first radially distal point. The first forward cutting edge forms an acute first entering angle, the second forward cutting edge forms an obtuse second back clearance angle, and the second rearward cutting edge forms an acute second entering angle.

Provided is a cutting tool in which one end side of a protruding cutting edge is sharpened while wear resistance is improved. The cutting tool of the present invention includes an end surface, a peripheral side surface that intersects the end surface, and a cutting edge in an intersecting ridgeline portion between the end surface and the peripheral side surface. When first and second points (A and B) are set on the cutting edge, the first point (A) protrudes further toward an outer side of the cutting tool than the second point (B). The cutting tool has a coating film on its surface. The cutting edge has a portion in which the thickness of the coating film gradually increases toward the second point (B) from the first point (A).

The invention relates to a cutting tool with a holder, a cutting insert and a screw, wherein the holder has at least one seat with a base, a first side wall and a second side wall, wherein in a plane parallel to the base the first side wall extends in a first direction and the second side wall includes an acute angle (C) with the first side wall, wherein the base has a threaded hole for receiving the screw, wherein the cutting insert has a cut-out for the screw, wherein the cutting insert has a base contact surface, a first positioning surface and a second positioning surface, and wherein in a locked position the base contact surface, the first positioning surface and the second positioning surface of the cutting insert contact the base, the first side wall and the second side wall of the at least one seat, respectively, wherein the second side wall is offset from the threaded hole in the first direction towards a front end of the seat, and in that a screw head of the screw and the cut-out of the cutting insert are provided with complementary conical surfaces, such that when tightening the screw the cutting insert is forced with the first positioning surface and the second positioning surface against the first side wall and the second side wall, respectively.

A double sided V-shaped cutting insert includes insert front and back surfaces and a peripheral surface extending therebetween. The peripheral surface has a forward surface, a first planar converging surface, and a first rake surface extending between the forward surface and the first converging surface. A second planar converging surface forms a convergence angle , 3045 with the first converging surface. A second rake surface extends between the forward surface and the second converging surface. In a view perpendicular to the insert front surface, the cutting insert exhibits mirror symmetry about a bisector plane passing between the first and second rake surfaces. The first and second rake surfaces each face away from the bisector plane. The first rake surface tends towards the bisector plane more than the first converging surface, and the second rake surface tends towards the bisector plane more than the second converging surface.

Provided is a cutting tool that simultaneously improves both fracture resistance and wear resistance. The cutting tool according to the present invention has an end surface, a peripheral side surface intersecting with the end surface, and a cutting edge in an intersecting ridge part along the end surface and the peripheral side surface, and when first and second points A and B are defined on the cutting edge, the first point A protrudes further toward an outer side of the cutting tool than the second point B. The cutting edge has a honing surface. The honing surface has a portion, the width of which gradually increases from the first point A toward the second point B.

A face grooving tool body includes a blade portion having a top surface and an opposite bottom surface, a first side surface and an opposite second side surface, and a front end and an opposite rear end. A longitudinal axis of the blade portion coincides with a primary cutting feed direction of the blade portion. An upper blade portion is associated with the top surface and a lower blade portion is associated with the bottom surface, the upper and lower blade portions being separated by a slit. The second side surface of the lower blade portion is curved around a second side surface axis of curvature parallel to the longitudinal axis. A key hole is formed in the blade portion. The slit includes a slit portion that has the shape of a concave function in a side view.