A cutting element has a cutting head and a shaft. The cutting head is carried by the shaft and protrudes over the shaft transversely relative to a longitudinal extent of the shaft. The cutting head has a cutting edge, the cutting edge follows a circle segment with a circle center at a side of the shaft located in a virtual cutting head plane and is constructed symmetrically, when viewed in a direction perpendicular to the cutting head plane, with respect to a virtual cutting edge axis of symmetry which is contained in the cutting head plane. The cutting head has a chip guiding structure. The chip guiding structure is associated with the cutting edge, has a chip guiding groove and a plurality of chip guiding elements. Each chip guiding element has a longitudinal rib and a transverse rib.

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.

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 solid-lubricated metal cutter and processing method relates to the technical field of metal cutters. A surface texture morphology is worked out on a metal cutter, a solid lubricant is filled into the surface texture morphology, and a convex dam is arranged on the cutter surface on which surface texture morphology is located at a chip flow side. The surface texture morphology has micro-pit and micro-boss features, and can exert antifriction effect of a solid lubricant and anti-adhesion effect of micro-protrusions. The convex dam is arranged at an end of the micro-texture region away from the cutting blade, so that a part of the solid lubricant flows back to the texture region and thereby the utilization efficiency and retentiveness of the solid lubricant are improved.

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).

A cutting insert of an embodiment includes a cutting edge located at an intersecting part of an upper surface and a side surface. The cutting edge includes a corner cutting edge, a major cutting edge, and a flat cutting edge. The upper surface includes a first land surface located along the corner cutting edge, a second land surface located along the major cutting edge, and a third land surface located along the flat cutting edge. A maximum value of a width of the third land surface is smaller than a maximum value of a width of each of the first land surface and the second land surface in a top view.

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.

A cutting tool has an insert holder with an indexable cutting insert removably secured therein. The cutting insert has upper and lower end surfaces with a peripheral side surface and a through bore extending therebetween, and a plurality of upper cutting edges formed on an upper peripheral edge. The peripheral side surface includes a non-circular upper relief surface adjacent the upper peripheral edge and a circular upper abutment surface spaced apart from the upper peripheral edge. Each upper cutting edge exhibits mirror symmetry about a bisector plane, and is non-linear in a side view. The through bore has an inner undercut formed by upper and lower bore surfaces located on opposite sides of a median plane, and a clamping member makes contact with one of the upper and lower bore surfaces at an inner contact zone located between the median plane and a seat surface of the insert holder.

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 cutting insert of one aspect includes a top surface including a first corner portion and a second corner portion; and a top cutting edge. The top cutting edge includes a first corner cutting edge, a first major cutting edge, a second corner cutting edge, and a second major cutting edge. The top surface includes a first breaker protrusion and a second breaker protrusion. A gap between the first breaker protrusion and the first corner cutting edge is larger than a gap between the second breaker protrusion and the second corner cutting edge, a gap between the first breaker protrusion and the first major cutting edge becomes larger as a distance from the first corner cutting edge increases, and a gap between the second breaker protrusion and the second major cutting edge becomes smaller as a distance from the second corner cutting edge increases.