A cutting insert according to one aspect has a flat plate shape including a first main surface having a polygonal shape, a second main surface located opposite to the first main surface, and an outer peripheral surface located between the first main surface and the second main surface. The cutting insert includes a cutting portion located in regions including at least a corner portion of the first main surface, and a main body portion located in a region other than the corner portion. A thickness of the main body portion is larger than a thickness of the cutting portions, and the main body portion includes a recessed portion or a protruding portion located in the outer peripheral surface thereof.

A cutting insert for a tool for machining a workpiece, comprising a first side, an opposite second side and a bore running along a bore axis. The bore penetrates the cutting insert and extends from the first side to the second side. The cutting insert comprises at least three cutting heads arranged distributed on a periphery of the cutting insert, wherein each of the at least three cutting heads comprises a cutting edge, which runs transversely to the first side and the second side and extends between the first side and the second side. The at least three cutting heads comprise a first cutting head, a second cutting head, which in a peripheral direction directly follows the first cutting head, and a third cutting head, which in the peripheral direction directly follows the second cutting head. The cutting insert has a first support surface arranged on the first side, which first support surface runs orthogonal to the bore axis and at least partially surrounds the bore. The cutting insert is rotationally symmetric to the bore axis and mirror-symmetric to a center plane which runs perpendicular to the bore axis and divides the cutting insert into two equally sized halves. Viewed in a top view along the bore axis, an imaginary straight connecting line between the cutting edge of the first cutting head and the cutting edge of the third cutting head intersects neither the bore nor the first support surface.

A tangential cutting insert for a turning tool is described, which comprises a first tangential cutting insert side and a second tangential cutting insert side, wherein one of the tangential cutting insert sides is assigned more than two cutting edges, and the cutting edges are arranged in a star shape about a tangential cutting insert center axis. The tangential cutting insert is produced completely from cubic crystalline boron nitride, polycrystalline cubic boron nitride, polycrystalline diamond, or ceramic. In addition, a cutting tool with such a tangential cutting insert is presented. A method for producing a tangential cutting insert is also explained.

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.

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).

Inclined surfaces are formed on a rake face and a recessed groove is formed in the central portion between the inclined surfaces. A groove width of the recessed groove gradually increases from the position of the end cutting edge toward the rear, then gradually decreases such that the recessed groove has a narrowest portion at a position P2 forward of the position P3 of an upper end of a breaker wall and rearward of a positive rake angle rear end position P1, and then gradually increases toward the rear up to the position P3 of the upper end of the breaker wall. The dimensional relation W1<W2<W3 holds, where W1 is the groove width at the end cutting edge, W2 is the groove width at the narrowest portion, and W3 is the groove width at the position P3 of the upper end of the breaker wall.

A cutting tool having a tool holder, cutting insert and clamping member. The tool holder includes an elongated supporting surface extending in a rearward-to-forward direction. The cutting insert has a central portion and three cutting portions, the central portion having two opposing side surfaces and three spaced apart locating surfaces defining a first imaginary triangle. The cutting insert is indexable about a central axis intersecting the two side surfaces. Each locating surface intersects two of three bisector planes containing the central axis and bisecting respective corners of the first imaginary triangle, and the cutting edge of each cutting portion is located entirely outside of the first imaginary triangle. In each index position the clamping member is located entirely rearward of a first vertical plane containing the central axis and perpendicular to the rearward-to-forward direction, and one of the locating surfaces is in clamping contact with the supporting surface.

A cutting insert for a tool for machining a workpiece, comprising a first cutting edge and a first cutting insert bore, wherein the cutting insert has an elongate shape and extends along a cutting insert longitudinal direction, wherein the first cutting insert bore extends along a first bore axis, which runs substantially orthogonally to the cutting insert longitudinal direction, wherein the cutting insert has a laterally protruding elevation, which is arranged on a side of the cutting insert that is oriented transversely to the first bore axis, and wherein on the elevation are arranged a first lateral holder contact surface, an axial holder contact surface and a first horizontal holder contact surface for the bearing contact of the cutting insert against a tool holder, wherein the first lateral holder contact surface runs substantially orthogonally to the first bore axis, and wherein the axial holder contact surface and the first horizontal holder contact surface run substantially orthogonally to the first lateral holder contact surface and transversely to each other.

A cutting edge configuration of a cutting tool for performing a cutting process on a surface (21) of a workpiece (19), the cutting tool including a rake face (3) provided with first and second cutting edges (11, 13), the cutting tool being moved relative to the surface-to-be-cut (21) with the first and second cutting edges (11, 13) cutting thereinto to thereby perform the cutting process, wherein the first cutting edge (11) is positioned ahead of the second cutting edge (13) in a cutting direction (z-direction) of the cutting tool to provide the rake face (3) with a feed-direction (y-direction) rake-angle, and the cutting tool is fed in a direction from a side of the second cutting edge (13) to a side of the first cutting edge (11).

Chip discharge during high-feed machining and low-feed machining particularly in a high-depth-of-cut state or the like is improved so as to provide adaptability to a wide range of cutting conditions during low depth and high depth cutting and during low-feed and high-feed machining and allow so-called freedom of feed during cutting to be improved. A cutting insert includes a cutting edge body and a substrate to which the cutting edge body is joined. The cutting edge body has a prismatic shape having a longitudinal direction and a lateral direction perpendicular to the longitudinal direction and includes a cutting edge formed on an intersecting edge between a peripheral side surface and an upper surface of the cutting edge body having the prismatic shape and a recessed part formed at a position on the upper surface of the cutting edge body which is more distant from the intersecting edge than from the cutting edge. The substrate has a projected part upwardly projecting from the upper surface of the cutting edge body.