A cutting insert according to an embodiment has a polygonal shaped upper surface, a lower surface, a side surface, and a cutting edge. The cutting edge has an arc-shaped first corner edge, an arc-shaped second corner edge, and a wiper edge located between the first corner edge and the second corner edge. The wiper edge has an arc-shaped first wiper edge and an arc-shaped second wiper edge located closer to the second corner edge than the first wiper edge. R0<R1<R2 is satisfied wherein R1 is a radius of curvature of the first wiper edge, R2 is a radius of curvature of the second wiper edge, and R0 is a radius of curvature of each of the corner edges in a top view.

A cutting tool including a tool body with an insert seat and an associated clamp pocket, a cutting insert releasably mountable in the insert seat, a clamp received in the clamp pocket and a screw that extends with play through a through hole in the clamp and is engaged in a hole at the bottom of the clamp pocket, is provided. Upon tightening of the screw, the clamp will slide against an inclined guide surface in the slide pocket via a slide surface on the clamp, which will force the clamp to move transversally to the screw shaft towards the cutting insert such that a clamp protrusion on the clamp is moved into a recess in the cutting insert and clamping surfaces on the clamp are pressed tightly against corresponding contact surfaces on the cutting insert.

An object is to provide a cutting insert for a milling cutter with which efficiency in machining can be increased. The cutting insert includes two polygonal main surfaces facing each other and side surfaces each connected to a corresponding side of each of the main surfaces. The side surfaces include a major side surface through which an attachment hole extends, a first minor side surface perpendicular to the major side surface, and a second minor side surface disposed between the first minor side surface and the major side surface. A ridge between each of the main surfaces and the major side surface forms a major cutting edge, and a ridge between each of the main surfaces and the second minor side surface forms a minor cutting edge. An angle between the major cutting edge and the minor cutting edge is 145 or larger.

A milling insert, including an upperside, an underside, and a reference plane parallel to the upperside and the underside. A plurality of indexable cutting edges are formed along a peripheral borderline in transitions between at least the upperside and a number of clearance surfaces. Each cutting edge includes a chip-removing main edge and a surface-wiping secondary edge, the secondary edge forming an obtuse angle with the main edge as viewed in planar view from the upperside. The main edge, from a first end of the main edge adjacent to the secondary edge, first declines toward the underside of the milling insert and then, from a lowest part, rises toward an opposite second end of the main edge. The secondary edge is inclined at an angle () in relation to the reference plane as viewed perpendicularly to the clearance surface of the secondary edge, such that a first end of the secondary edge connected to the main edge is situated on a lower level than the opposite, second end of the secondary edge.

A milling insert, including an upperside, an underside, and a reference plane parallel thereto. A plurality of indexable cutting edges are formed along a peripheral borderline in transitions between at least the upperside and a number of clearance surfaces. Each cutting edge includes a chip-removing main edge and a surface-wiping secondary edge. The main edge, from a first end of the main edge adjacent to the secondary edge, declines toward the underside of the milling insert and then, from a lowest part, rises toward an opposite second end of the main edge. The secondary edge is inclined at an angle () in relation to the reference plane as viewed perpendicularly to the clearance surface of the secondary edge, such that a first end of the secondary edge connected to the main edge is situated on a lower level than the opposite, second end of the secondary edge.

A first outer region of an outer inclined surface of a cutting insert according to one aspect bas a width in a direction orthogonal to a first portion of a first side decreasing with distance from the first corner. A second outer region of the outer inclined surface bas a width in a direction orthogonal to a second portion of the first side increasing with distance from the first corner.

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.