A cutting insert has a plate shape centered on an insert center axis. The cutting insert includes a front surface and a back surface facing an insert axial direction, an outer peripheral surface facing outward in an insert radial direction, and a cutting edge at an intersecting ridge line between the front surface and the outer peripheral surface. The back surface has a flat shape perpendicular to the insert center axis. The outer peripheral surface includes a flank surface coupled. The flank surface is inclined inward in the insert radial direction as extending in the insert axial direction from the front surface side to the back surface side. The front surface includes a rake surface. The rake surface is inclined from a back surface side to a front surface side in the insert axial direction as extending inward in the insert radial direction from the cutting edge.

A cutting tool including a toolholder and a round cutting insert for mounting on a pocket floor of the toolholder. The toolholder includes the toolholder pocket floor having a bore therein and a plurality of grooves in the pocket floor arranged radially about the bore, wherein adjacent grooves are radially offset by a groove offset angle x. The round cutting insert includes an upper surface having a cutting edge, a lower surface opposite the upper surface, an exterior side surface between the upper surface and the lower surface, an interior side surface defining an aperture extending from the upper surface to the lower surface, and a plurality of lugs arranged radially about the aperture, wherein adjacent lugs are radially offset by a lug offset angle y, and wherein a ratio of y:x is an integer greater than or equal to 2.

A cutting insert for a shoulder milling tool has a trigonal shape and includes a first surface, a second surface, and a circumferential surface extending between the first surface and the second surface. The circumferential surface includes a countersunk circumferential waist portion. The circumferential surface has a first and a second clearance surface extending along a first and a second main cutting edge. Each of the first and second clearance surfaces forma a negative nominal clearance angle. Each of the first and second main cutting edges is arranged inside the countersunk circumferential waist portion, as seen in the view towards the first and second surfaces, respectively.

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.

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.

Provided is a milling tool that allows a life of a tool main body to be elongated. The milling tool includes a replaceable cutting insert and a tool main body in which at least one insert seat that fixes the cutting insert is provided on a distal end side. The tool main body has a reinforcing wall covering at least a portion of the cutting insert when the cutting insert that is in a state of being fixed to the tool main body is viewed from the distal end side.

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.

A double-sided cutting insert for milling includes first and second major faces, a peripheral surface arranged between the major faces and including a first main side face, a first main cutting edge formed at an intersection between the first main side face and the first major face, a second main cutting edge formed at an intersection between the first main side face and the second major face, first and second inclined side surfaces, which are formed on the first main side face and which are inclined towards each other to form a depression on the first main side face, and a chip deflecting member formed on the first main side face as a protrusion across the depression and which includes a chip deflecting surface configured to deflect chips, which hit the first main side face, away from the depression.

A cutting insert of the present invention includes an upper surface, a lower surface, a side surface, a cutting edge, and a mounting hole penetrating the upper surface and the lower surface, in which the cutting edge includes a main cutting edge, a corner cutting edge extending from the main cutting edge, and a sub-cutting edge extending from the corner cutting edge, the side surface includes a main cutting edge flank surface and a sub-cutting edge flank surface, the main cutting edge flank surface includes a first main cutting edge flank surface extending from the main cutting edge, and a second main cutting edge flank surface extending from the lower surface, the sub-cutting edge flank surface includes a first sub-cutting edge flank surface extending from the sub-cutting edge, and a second sub-cutting edge flank surface extending from the lower surface, the first sub-cutting edge flank surface and the second sub-cutting edge flank surface together form a stepped portion, and the second sub-cutting edge flank surface protrudes from an imaginary plane extending from the first sub-cutting edge flank surface.