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.

A turning insert includes a top surface, an opposite bottom surface, side surfaces connecting the top surface and the bottom surface and two opposite nose portions. Each nose portion includes a convex nose cutting edge, a first cutting edge and a second cutting edge. The convex nose cutting edge connects the first and second cutting edges. A bisector extends equidistantly from the first and second cutting edges. In a top view the first and second cutting edges on the same nose portion form a nose angle () of 70-85 relative to each other. Each nose portion includes a third convex cutting edge adjacent to the first cutting edge and a fourth cutting edge adjacent to the third cutting edge. In a top view the fourth cutting edge forms an angle () of 0-34 relative to the bisector.

A cutting insert of one aspect includes a top surface including a corner portion and a pair of side portions each adjacent to the corner portion, a bottom surface, a side surface located between the top surface and the bottom surface, and a corner cutting edge disposed at the corner portion. In such a cutting insert, the top surface includes a first rake surface located along the corner cutting edge, a raised portion located farther on the inner side than the first rake surface, and a second rake surface located between the corner cutting edge and the raised portion. Moreover, a rake angle at a first region of the second rake surface corresponding to a center of the corner cutting edge is greater than a rake angle at a second region of the second rake surface located beside the first region.

A cutting insert according to one aspect of the present invention includes a polygonal columnar shape, and includes an upper surface, a lower surface and a side surface located between the upper surface and the lower surface, and a cutting edge is formed at an intersecting portion between the upper surface and the side surface, the upper surface includes a main portion of a convex shape including a flat upper end surface, a first projecting portion which projects from the main portion to a corner portion of the upper surface, and a pair of second projecting portions which each project from the first projecting portion to a periphery of the upper surface to interpose a region between a front end of the first projecting portion and the corner portion, and each of upper ends of the pair of second projecting portions is spaced part from the first projecting portion.

The present invention provides a novel groove cutter with chip breaker, including: a cutter body; a cutter head arranged at the end part of the cutter body, a cutting edge being arranged at a bordering position of the cutter head; and a chip breaker arranged on the cutter head, wherein the chip breaker comprises a breaker bottom and a breaker wall, the breaker bottom being connected to the cutting edge, the breaker wall being arranged on one side of the breaker bottom away from the cutting edge, the breaker bottom being non-coplanar with the breaker wall, an intersecting line of the breaker bottom and the breaker wall including multiple connecting sections, and one curved transition section being arranged between two adjacent connecting sections. By means of the technical solutions provided in the present application, the problem that breaking chips in a groove machining process is difficult in the prior art can be solved.

A cutting insert includes a land and a breaker flute on a rake face, the land providing a cutting edge by intersecting a flank face. The breaker flute includes breakers. A width T of a portion of the land that extends along a portion of the cutting edge that is at a round corner portion is 0.05 mm<T<0.15 mm. A plurality of crest portions each extending over the entirety of the portion of the cutting edge that is at the round corner portion are provided on a sloping surface of the breaker flute that is on a land side. The crest portions are arranged side by side in a depth direction of the breaker flute. A rake angle of at least one of inclined surfaces that form each of the crest portions is expressed as >20.

An object of the present invention is to configure a cutting-off processing tool that includes a cutting edge angled at an end cutting edge angle and causes evacuation of chips to be controlled so that the chips are evacuated in the tool axis direction, thereby reducing concerns about damage to a processed surface by the chips. The cutting-off processing tool includes a cutting edge angled at the end cutting edge angle. In the cutting-off processing tool, an upper surface has a shape laterally asymmetric about a center in a width direction. In the cutting-off processing tool, when b is a rake angle of a rake face on a first corner side positioned on a foremost end of the tool, and c is a rake angle of the rake face on a second corner side, b>c is satisfied.

A turning insert includes a top surface, an opposite bottom surface, a reference plane located parallel to and between the top surface and the bottom surface, and a center axis extending perpendicular to the reference plane and intersecting the reference plane (RP), the top surface and the bottom surface. Side surfaces connect the top surface and the bottom surface. Three nose portions are formed symmetrically relative to the center axis. Each nose portion includes a first cutting edge, a second cutting edge and a convex nose cutting edge connecting the first) and second cutting edges. In a top view the first and second cutting edges on the same nose portion form a nose angle of 25-50 relative to each other. The distance from the first cutting edge to the reference plane varies in such a way that that this distance is decreasing at increasing distance from the nose cutting edge.

A turning insert includes a top surface, an opposite bottom surface, side surfaces connecting the top surface and the bottom surface and two opposite nose portions. Each nose portion includes a convex nose cutting edge, a first cutting edge and a second cutting edge. The convex nose cutting edge connects the first and second cutting edges. A bisector extends equidistantly from the first and second cutting edges. In a top view the first and second cutting edges on the same nose portion form a nose angle () of 70-85 relative to each other. Each nose portion includes a third convex cutting edge adjacent to the first cutting edge and a fourth cutting edge adjacent to the third cutting edge. In a top view the fourth cutting edge forms an angle () of 0-34 relative to the bisector.

A method to form a surface on a metal work piece includes providing a turning insert having a first cutting edge, a second cutting edge and a convex nose cutting edge connecting the first and second cutting edges, a nose angle formed between the first and second cutting edges being less than or equal to 85; arranging the second cutting edge such that it forms a back clearance angle of more than 90 in a feed direction; positioning all parts of the turning insert ahead of the nose cutting edge in the feed direction; rotating the metal work piece around a rotational axis in a first direction; and moving the turning insert in a direction parallel to or at an angle less than 45 relative to the rotational axis, such that the surface at least partly is formed by the nose cutting edge.