A wiper insert includes three first corner portions and three second corner portions which are alternately aligned on a polygonal surface in an insert circumferential direction. A cutting edge has a first cutting edge that performs a finishing operation on a work material, and a second cutting edge. An outer peripheral surface has a first flank face, a second flank face, and a first restraint surface disposed outward from the second cutting edge in an insert radial direction. When viewed in an insert axial direction, an insert shape is rotationally symmetrical by 180° around a rotation center axis passing through the second corner portion adjacent to a first side of a predetermined first corner portion in the insert circumferential direction and an insert center axis.

A cutting insert has an upper surface, a lower surface and a lateral surface. The upper surface has a first upper side, and a second upper side. The lower surface has a first lower side and a second lower side. The lateral surface has a first lateral surface, a second lateral surface, and a third lateral surface. The first lateral surface has a first concave part having a first constraining surface having a flat shape. The second lateral surface has a second concave part having a second constraining surface having a flat shape. The third lateral surface has a convex part. The first concave part and the second concave part are separated from each other by the convex part.

The invention relates to a cutting insert having a polygonal upper side. Cutting edges, which are alternately configured as roughing cutting edges and finishing cutting edges, are provided at the edges of the upper side. The finishing cutting edges define an incircle (K1) having a diameter that is enlarged in comparison to a nominal size of the cutting insert, and the roughing cutting edges define an incircle (K2) having a diameter that is reduced in comparison to the nominal size of the cutting insert. The invention further relates to a cutting tool having a tool body on which at least one such cutting insert is disposed.

Provided is a cutting insert configured to be able to realize downsizing of a cutting tool. A cutting insert includes: an upper surface and a lower surface facing each other and having a plurality of corner parts; a side surface connecting the upper surface and the lower surface and forming intersecting edges with the upper surface and the lower surface, respectively; and a through hole that has a central axis extending from the upper surface to the lower surface and that is formed for penetration from the upper surface to the lower surface. A corner cutting edge arranged at a position corresponding to a corner part of the upper surface, a minor cutting edge connected to a first end of the corner cutting edge, and a major cutting edge connected to a second end of the corner cutting edge are formed on the intersecting edge between the upper surface and the side surface. A flank of the corner cutting edge and a recessed part located on the lower surface side of the flank of the corner cutting edge are formed on the side surface.

A cutting insert includes a polygonal plate-shaped insert main body having two polygonal surfaces, a side surface having a flank, and a cutting edge to be formed in an intersection ridgeline portion between a rake face and the flank. The insert main body has a rotationally symmetrical shape with respect to an insert center line, and has a front-rear reversely symmetrical shape with respect to the polygonal surface. The cutting edge includes a corner cutting edge, a major cutting edge extending from an one end of the corner cutting edge, and a wiper cutting edge extending from an one end of the major cutting edge in a direction intersecting the major cutting edge at an obtuse angle. A first region is disposed where a clearance angle of the flank gradually decreases to a negative angle after continuously passing through 0° from a positive angle.

A cutting insert includes a polygonal plate-shaped insert main body having two polygonal surfaces, a side surface having a flank, and a cutting edge to be formed in an intersection ridgeline portion between a rake face and the flank. The insert main body has a rotationally symmetrical shape with respect to an insert center line, and has a front-rear reversely symmetrical shape with respect to the polygonal surface. The cutting edge includes a corner cutting edge, a major cutting edge extending from an one end of the corner cutting edge, and a wiper cutting edge extending from an one end of the major cutting edge in a direction intersecting the major cutting edge at an obtuse angle. A first region is disposed where a clearance angle of the flank gradually decreases to a negative angle after continuously passing through 0° from a positive angle.

A cutting tool includes a toolholder and a cutting insert. The toolholder includes a toolholder pocket having a pocket wall including a first anti-rotation engagement surface and a second anti-rotation engagement surface. The cutting insert is mounted in the toolholder pocket. The cutting insert includes: an upper surface, the upper surface having a plurality circular sinusoidal cutting edges; a lower surface opposite the upper surface; and an exterior sidewall between the upper surface and the lower surface. The first anti-rotation engagement surface and the second anti-rotation engagement surface of the pocket wall of the toolholder engage the exterior sidewall of the cutting insert to resist rotation of cutting insert.

Provided is a cutting insert in which cutting edges in a plurality of sections can be used, and it is possible to keep chips, which are discharged from a cutting edge in a section that is being used, from damaging an unused cutting edge in an adjacent section. An edge where an upper surface and a peripheral side surface intersect is divided into a plurality of sections AB, BC, CD, and so on. In each of the plurality of section, the section AB, for example, includes one minor cutting edge and one major cutting edge that is longer than the minor cutting edge. The major cutting edge is inclined at an angle α to be away from a lower surface gradually while extending away from the minor cutting edge. A height position of the upper surface in an up-down direction in which the upper surface and the lower surface oppose each other does not change as the upper surface extends toward the attachment hole, or the height position decreases in a direction from the upper surface toward the lower surface.

Provided is a cutting insert in which cutting edges in a plurality of sections can be used, and it is possible to keep chips, which are discharged from a cutting edge in a section that is being used, from damaging an unused cutting edge in an adjacent section. An edge where an upper surface and a peripheral side surface intersect is divided into a plurality of sections AB, BC, CD, and so on. In each of the plurality of section, the section AB, for example, includes one minor cutting edge and one major cutting edge that is longer than the minor cutting edge. The major cutting edge is inclined at an angle α to be away from a lower surface gradually while extending away from the minor cutting edge. A height position of the upper surface in an up-down direction in which the upper surface and the lower surface oppose each other does not change as the upper surface extends toward the attachment hole, or the height position decreases in a direction from the upper surface toward the lower surface.

A double-sided cutting insert for milling has a first cutting edge formed at a transition from a top side to a circumferential lateral surface and a second cutting edge formed at a transition from a bottom side to the circumferential lateral surface. A reference plane (R) runs normal to an axis of symmetry (S). The cutting edges have main cutting edge portions and face cutting edge portions arranged in alternation, which extend between raised cutting corners and lowered cutting corners. The circumferential lateral surface has face free surfaces, which extend along the face cutting edge portion and which approach the axis of symmetry (S) with increasing distance from the associated face cutting edge portion. The circumferential lateral surface has main free surfaces, which extend along the main cutting edge portion and which move farther away from the axis of symmetry with increasing distance from the associated main cutting edge portion.