A cutting insert has a cutting portion corner formed at the intersection of a rake surface, a forward cutting portion surface and a relief surface. A cutting edge is formed at an intersection of the rake surface and the relief surface with a land that is located on the rake surface and that extends along, and negatively away from, the cutting edge. A chip-control arrangement is located at the rake surface and includes an elongated projection and plurality of spaced apart elongated protuberances that extend from the projection to the cutting edge, so that the land has a plurality of spaced apart bulging land portions. A non-rotary cutting tool has an insert holder having an insert pocket and the cutting insert releasably retained therein.

A cutting insert has a cutting edge formed at an intersection of a rake surface and a relief surface, with a chip-control arrangement located at the rake surface. The chip-control arrangement includes a depression that includes a depression declining surface that extends downwardly in a direction away from the major cutting edge. A chip deflecting surface located rearward of the depression is inclined upwardly in a direction away from the major cutting edge. A chip former includes an interposed projection that extends from the chip deflecting surface to the depression declining surface, and two lateral protuberances that extend from opposite sides of the interposed projection to the depression declining surface beyond a forwardmost portion of the interposed projection.

A cutting insert has a cutting edge formed at an intersection of a rake surface and a relief surface, with a chip-control arrangement located at the rake surface. The chip-control arrangement includes a depression that includes a depression declining surface that extends downwardly in a direction away from the major cutting edge. A chip deflecting surface located rearward of the depression is inclined upwardly in a direction away from the major cutting edge. A chip former includes an interposed projection that extends from the chip deflecting surface to the depression declining surface, and two lateral protuberances that extend from opposite sides of the interposed projection to the depression declining surface beyond a forwardmost portion of the interposed projection.

Provided is a cutting tool for back turning capable of improving chipping resistance. A cutting tool wherein a wall surface of a chip breaker includes a first wall surface that is formed along a first ridgeline, and a reinforcing surface that is connected to the first wall surface and a first end surface at an end portion of the chip breaker on the side of a first cutting edge, and that forms an angle of 90 degrees or an obtuse angle with the first end surface.

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 cutting insert that has, in an upper surface, a convex portion including a main portion having a flat upper end surface, a first portion projecting from the main portion to a corner portion of the upper surface, a second portion projecting from the first portion to the corner portion, and a third portion projecting from the second portion to the corner portion. Upper end heights of the second portion and the third portion are fixed toward the corner portion, respectively. The first portion and the second portion are connected by a first flat inclined wall surface, the second portion and the third portion are connected by a second wall surface of a convex curved surface, and a front end of the third portion and the breaker groove are connected by a third wall surface of a convex curved surface.

A cutting tool according to an aspect of the present disclosure includes a cutting edge portion which contains at least one of cubic boron nitride and polycrystalline diamond. The cutting edge portion includes a flank face, a negative land contiguous to the flank face, and a cutting edge formed by a ridgeline between the flank face and the negative land. At least one of the negative land and the flank face is provided with a plurality of recesses and a projection. The projection is formed by arranging the edges of adjacent recesses in contact with each other.

The present disclosure relates to a cutting insert. The cutting insert according to the exemplary embodiment of the present disclosure has a dot formed between a main cutting edge and a chip breaker, and the dot has a bridge formed between the main cutting edges. Therefore, a chip, which is produced during a cutting process, may come into contact with three points on a main cutting edge land portion, the bridge, and the dot. The chip may discharge heat generated from the cutting insert while the chip comes into contact with the three points.

A turning insert includes a top surface, an opposite bottom surface, and a reference plane therebetween. A center axis intersects the top and bottom surfaces and a side surface connects the top and bottom surfaces. A circular cutting edge is adjacent the top surface and the side surface. The top surface includes a set of first protrusions, which are elongated in a direction parallel to the adjacent cutting edge. A greatest distance from the reference plane to the first protrusions is greater than a distance from the reference plane to the cutting edge. The bottom surface has a set of radial grooves and includes a set of flat surfaces. The flat surfaces extend in a plane parallel to the reference plane, wherein in a top view each first protrusion is symmetrical in relation to a line extending between the center axis and a mid-point of the first protrusion.

A cutting insert in the present disclosure includes an upper surface, a lower surface, a side surface, and an edge. The upper surface includes a first corner part and a second corner part. The edge is located in a region which is located between the first corner part and the second corner part. The edge includes a first edge located at a side of the first corner part, a second edge located at a side of the second corner part, and a third edge located between the first edge and the second edge. The edge has a curvilinear shape being recessed toward the lower surface in a side view. Each of a radius of curvature R1 of the first edge and a radius of curvature R2 of the second edge is smaller than a radius of curvature R3 of the third edge in a side view.