A turning insert includes a head portion connected to a stem portion. A CBN cutting edge includes a surface generating cutting edge and two major cutting edge portions, such that each major cutting edge portion forms an angle of 5-20° in relation to a tangent line of the cutting edge at a forward point of the cutting edge.

A turning insert includes a head portion connected to a stem portion. A CBN cutting edge includes a surface generating cutting edge and two major cutting edge portions, such that each major cutting edge portion forms an angle of 5-20° in relation to a tangent line of the cutting edge at a forward point of the cutting edge.

A cutting insert and a cutting tool which can suppress lowering of blade-edge positional accuracy while holding by a holder having a small thickness is enabled are provided.

The cutting insert includes a first end surface, a second end surface, and a peripheral side surface connected to the first end surface and the second end surface and having a rake face, a flank, and a cutting edge formed in a connection region between the rake face and the flank, and a through hole penetrating the first end surface and the second end surface is formed. It is the cutting insert including a first contact surface substantially perpendicular to a center axis direction of the through hole and capable of contacting the holder, a second contact surface substantially in parallel with the center axis direction of the through hole, substantially perpendicular to a plane including the first contact surface and capable of contacting the holder, and a third contact surface inclined with respect to the center axis direction of the through hole and capable of contacting the holder, and a cutting tool including the cutting insert as above.

A cutting insert for parting off a metal work piece includes an elongated body having a top surface, a bottom surface, a first lateral surface, a second lateral surface connecting the top surface and the bottom surface at one lateral side each, a front surface connecting the first and second lateral surfaces, the top surface and the bottom surface, a longitudinal axis extending axially rearward from the front surface in a central plane, and a cutting head having a cutting edge. The cutting edge is formed at an intersection between the front surface and the top surface. The cutting edge includes a leading cutting corner at the first lateral side surface and a trailing cutting corner at the second lateral side surface. The trailing cutting corner is located axially rearward of the leading cutting corner. The cutting edge has a rearmost point located axially rearward from the trailing cutting corner.

A cutting insert for parting off a metal work piece includes an elongated body having a top surface, a bottom surface, a first lateral surface, a second lateral surface connecting the top surface and the bottom surface at one lateral side each, a front surface connecting the first and second lateral surfaces, the top surface and the bottom surface, a longitudinal axis extending axially rearward from the front surface in a central plane, and a cutting head having a cutting edge. The cutting edge is formed at an intersection between the front surface and the top surface. The cutting edge includes a leading cutting corner at the first lateral side surface and a trailing cutting corner at the second lateral side surface. The trailing cutting corner is located axially rearward of the leading cutting corner. The cutting edge has a rearmost point located axially rearward from the trailing cutting corner.

Provided is a cutting insert having two cutting parts that is capable of entering a workpiece more deeply and easily supports machining of a groove or hole having a small diameter in a workpiece. A cutting insert includes: a body having at least an inner surface to be fixed to a tool body of a cutting tool and an outer surface opposed to the inner surface; and two cutting parts protruding in opposite directions in a longitudinal direction of the body. The cutting part includes: a cutting upper surface; a cutting front surface; and a first cutting side surface and a second cutting side surface. A front cutting edge is located on an edge between the cutting upper surface and the cutting front surface. In a projection view of the body as seen from the longitudinal direction, the cutting upper surfaces of the two cutting parts are oriented in directions opposed to each other, and front cutting edges of the two cutting parts are disposed so as to be more away from each other as being closer to the first cutting side surface from the second cutting side surface.

A threading tool includes: a tool main body; and a cutting edge portion, which is provided on a tip portion of the tool main body and has a rake face and a flank face. The cutting edge portion includes: a primary cutting edge extending in a tooth width direction of the cutting edge portion; two corner edges, one and other of which are provided on one and other of both ends of the primary cutting edge, respectively, and are in a convex curve shape; and two secondary cutting edges, one and other of which extend from the one and the other of the two corner edges to a rear end side of the cutting edge portion, respectively. Two secondary cutting edges are shorter than the primary cutting edge. At least one of the two secondary edges is slanted to a direction intersecting the primary cutting edge in an obtuse angle.

A cutting insert having a first end surface, a second end surface, and a peripheral side surface. The peripheral side surface includes a rake surface, a front flank and a first cutting edge located in an intersecting edge between the rake surface and the front flank. The first end surface includes a central surface and a side flank located closer to the front flank as compared to the central surface. An intersecting edge between the central surface and the peripheral side surface serves as a first edge, and an intersecting edge between the side flank and the peripheral side surface serves as a second edge, and an angle formed by the first cutting edge and the first edge serves as a first angle α, and an angle formed by the first cutting edge and the second edge serves as a second angle β, wherein α is smaller than β.

A cutting insert having a first end surface, a second end surface, and a peripheral side surface. The peripheral side surface includes a rake surface, a front flank and a first cutting edge located in an intersecting edge between the rake surface and the front flank. The first end surface includes a central surface and a side flank located closer to the front flank as compared to the central surface. An intersecting edge between the central surface and the peripheral side surface serves as a first edge, and an intersecting edge between the side flank and the peripheral side surface serves as a second edge, and an angle formed by the first cutting edge and the first edge serves as a first angle α, and an angle formed by the first cutting edge and the second edge serves as a second angle β, wherein α is smaller than β.

An indexable parting blade has opposite blade first and second sides, a blade peripheral edge, a central index axis, and at least first, second and third insert pockets located along the blade peripheral edge. The parting blade also has first, second and third coolant channels, each forming a coolant path from a corresponding inlet to a corresponding one of the insert pockets. Each coolant channel includes a rake outlet opening out to a rake side of its corresponding insert pocket and a relief outlet opening out to a relief side of that same insert pocket. The inlet corresponding to a given coolant channel is located further from that coolant channel's insert pocket than at least one of (a) the inlet corresponding to a different coolant channel, and (b) the central index axis.