In a cutting tool rotatable about a tool axis, a reversible cutting insert is removably secured in a tool body. The cutting insert has opposing top and bottom end surfaces interconnected by a peripheral surface, and a median plane located therebetween. The peripheral surface includes four side surfaces alternating with four corner surfaces, the side and corner surfaces intersecting the top surface to form top major cutting edges and top corner cutting edges, respectively. Each side surface has a median surface and a top major relief surface. Each top major relief surface forms an acute internal top major relief angle with the median plane, and the median plane intersects the four median surfaces to define an imaginary median square. In a top end view of the cutting insert, the four top major cutting edges define an imaginary top major square rotationally offset from the imaginary median square.

A cutting insert for milling square shoulders has side surfaces each provided with a major cutting edge connected to an associated wiper edge on an adjacent side surface of the insert. The side surface provided with the major cutting edge has two generally flat and non-coplanar support surfaces arranged consecutively with respect to a direction of the extension of the major cutting edge and make different angles with a normal to a bottom surface of the insert. A border forming a limit of the support surfaces most distant to the bottom surface is inclined with respect to the bottom surface so that the distance of this border to the bottom surface increases in a direction of extension of the cutting edge towards the wiper edge.

A double-sided, polygonal cutting insert includes a first surface and a second surface opposite the first surface. A plurality of side surfaces extend between the first surface and the second surface. A plurality of primary concave cutting edges are formed at an intersection between the plurality of side surfaces and the first and second surfaces, and a plurality of convex wiper edges are formed at an intersection between the plurality of side surfaces and the first and second surfaces. Each wiper edge has a step extending radially outward from a respective side surface. The cutting insert is mounted in a cutting tool such that the primary cutting edge and a wiper edge contact a workpiece to produce a high-quality surface finish on the workpiece.

In a cutting tool rotatable about a tool axis, a reversible cutting insert is removably secured in a tool body. The cutting insert has opposing top and bottom end surfaces interconnected by a peripheral surface, and a median plane located therebetween. The peripheral surface includes four side surfaces alternating with four corner surfaces, the side and corner surfaces intersecting the top surface to form top major cutting edges and top corner cutting edges, respectively. Each side surface has a median surface and a top major relief surface. Each top major relief surface forms an acute internal top major relief angle with the median plane, and the median plane intersects the four median surfaces to define an imaginary median square. In a top end view of the cutting insert, the four top major cutting edges define an imaginary top major square rotationally offset from the imaginary median square.

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 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.

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 double-sided, polygonal cutting insert includes a first surface and a second surface opposite the first surface. A plurality of side surfaces extend between the first surface and the second surface. A plurality of primary concave cutting edges are formed at an intersection between the plurality of side surfaces and the first and second surfaces, and a plurality of convex wiper edges are formed at an intersection between the plurality of side surfaces and the first and second surfaces. Each wiper edge has a step extending radially outward from a respective side surface. The cutting insert is mounted in a cutting tool such that the primary cutting edge and a wiper edge contact a workpiece to produce a high-quality surface finish on the workpiece.

A double-sided, polygonal cutting insert includes a first surface and a second surface opposite the first surface. A plurality of side surfaces extend between the first surface and the second surface. A plurality of primary concave cutting edges are formed at an intersection between the plurality of side surfaces and the first and second surfaces, and a plurality of convex wiper edges are formed at an intersection between the plurality of side surfaces and the first and second surfaces. Each wiper edge has a step extending radially outward from a respective side surface. The cutting insert is mounted in a cutting tool such that the primary cutting edge and a wiper edge contact a workpiece to produce a high-quality surface finish on the workpiece.

The cutting edge has: a corner cutting edge; a flat cutting edge continuous to a first end portion of the corner cutting edge; and a main cutting edge continuous to a second end portion of the corner cutting edge opposite to the first end portion of the corner cutting edge. The rake face has: a first rising surface portion; and a first rake face portion continuous to the first rising surface portion and located opposite to the corner cutting edge when viewed from the first rising surface portion. When viewed in a direction perpendicular to the reference surface, the first boundary includes a first line segment extending, from one of the flat cutting edge and the corner cutting edge, in a direction crossing a straight line extending along the main cutting edge.