An indexable cutting insert has upper and lower surfaces with a peripheral surface extending therebetween and having four side surfaces alternating with four corner surfaces. The side and corner surfaces intersect the upper surface to form side and corner cutting edges, respectively. Each side cutting edge includes a primary cutting edge adjoining one of the corner cutting edges at a first endpoint and a secondary cutting edge adjoining another one of the corner cutting edges at a second endpoint. In a top view, the four primary cutting edges define an imaginary first square, each primary cutting edge is tangential to its adjoining corner cutting edge, and each secondary cutting edge is curved and entirely located in one of four imaginary quadrants. The insert is removably secured in a rotary cutting tool such that one of the secondary cutting edges contains the axially forwardmost point of the insert's upper peripheral edge.

A cutting insert comprises: a first end surface and a second end surface which are opposed to each other; a peripheral side surface which extends so as to connect the first end surface and the second end surface; a first cutting edge which is arranged in an intersecting edge between the first end surface and the peripheral side surface; and a second cutting edge which is arranged in an intersecting edge between the second end surface and the peripheral side surface. The peripheral side surface includes a first flank which is connected to the first cutting edge and an intermediate peripheral side surface portion which is arranged closer to the second end surface than the first flank. The first flank extends in a direction perpendicular to the first end surface. The intermediate peripheral side surface portion protrudes outward from the first flank.

A cutting insert having two opposing end surfaces, two identical opposing major side surfaces and two identical opposing minor side surfaces. Each end surface has four corners comprising two lowered corners and two raised corners, the two lowered corners being diagonally opposite each other, the two raised corners being diagonally opposite each other. The cutting insert also includes a major cutting edge formed at an intersection of each major edge and the end surface. A section of the major cutting edge proximate the raised corner constitutes a leading end of the major cutting edge, and a section of the major cutting edge proximate the lowered corner constitutes a trailing end of the major cutting edge. An angled margin only partially extends along the leading end of the major cutting edge and segments the major cutting edge.

An insert may include a base member and a resin layer located on the base member. The base member may include a first surface, a second surface, and a cutting edge. The first surface includes a rake surface region. The second surface may be adjacent to the first surface and includes a flank surface region. The cutting edge may be located in at least a part of a ridge line at which the first surface intersects with the second surface. The resin layer may not be located on the second surface but may be located on the first surface.

An indexable cutting insert has upper and lower surfaces with a peripheral surface extending therebetween and having four side surfaces alternating with four corner surfaces. The side and corner surfaces intersect the upper surface to form side and corner cutting edges, respectively. Each side cutting edge includes a primary cutting edge adjoining one of the corner cutting edges at a first endpoint and a secondary cutting edge adjoining another one of the corner cutting edges at a second endpoint. In a top view, the four primary cutting edges define an imaginary first square, each primary cutting edge is tangential to its adjoining corner cutting edge, and each secondary cutting edge is curved and entirely located in one of four imaginary quadrants. The insert is removably secured in a rotary cutting tool such that one of the secondary cutting edges contains the axially forwardmost point of the insert's upper peripheral edge.

The present invention provides a cutting insert in which suitable honing is formed on a cutting edge. The cutting insert is provided with: two end surfaces opposing each other; a peripheral side surface extending between the two end surfaces; and a cutting edge formed on an intersecting ridge between at least one of the two end surfaces and the peripheral side surface. The cutting edge at least includes a major cutting edge and an inner cutting edge. Honing is provided on the major cutting edge and the inner cutting edge. A width of second honing of the inner cutting edge is narrower than a width of first honing of the major cutting edge, as viewed from a side of the end surfaces.

A cutting insert (1) comprises: a first end surface (2) and a second end surface (3) which are opposed to each other; a peripheral side surface (4) which extends so as to connect the first end surface (2) and the second end surface (3); a first cutting edge (5a) which is arranged in an intersecting edge between the first end surface (2) and the peripheral side surface (4); and a second cutting edge (5b) which is arranged in an intersecting edge between the second end surface (3) and the peripheral side surface (4). The peripheral side surface (4) includes a first flank (4a1) which is connected to the first cutting edge (5a) and an intermediate peripheral side surface portion (4b) which is arranged closer to the second end surface (3) than the first flank (4a1). The first flank (4a1) extends in a direction perpendicular to the first end surface (2). The intermediate peripheral side surface portion (4b) protrudes outward from the first flank (4a1).

An insert detachably attached to an indexable rotary cutting tool, having an upper surface having cutting edges along the ridgeline, a lower surface, side surfaces, and a center hole for a fastening screw; each cutting edge having a corner cutting edge formed in each acute corner portion, and a bottom cutting edge and a peripheral cutting edge formed along the ridgelines on both sides of the corner cutting edge; the bottom cutting edge and the peripheral cutting edge having different clearance angles; a flank of the corner cutting edge having an angle-changing surface portion having a clearance angle continuously changing in a region from the bottom cutting edge to the peripheral cutting edge; and the length of the peripheral cutting edge being restricted by a receding portion adjacent to an upper end of the peripheral cutting edge.

An indexable rotary cutting tool comprising, a twist angle of the outer peripheral cutting edge having a positive value, an axial rake angle of the cutting edge of the corner R at a boundary point between the cutting edge of the corner R and the outer peripheral cutting edge has a positive value, the axial rake angle of the cutting edge of the corner R at the reference point has a negative value, at least the radial rake angle in a region between the boundary point and the reference point in an entire edge length region of the cutting edge of the corner R has a negative value, and the radial rake angle of the cutting edge of the corner R at the reference point is smaller than the radial rake angle of the cutting edge of the corner at the boundary point.

An indexable cutting insert for face milling with high feed rates has: an upper side, a lower side with a smaller outer circumference than the upper side, and side surfaces connecting the upper and lower sides. Rounded cutting corners are formed at the transition between the side surfaces and the upper side. The cutting corners are connected via convexly arched cutting edges, each running convexly curved from one cutting corner to an adjacent cutting corner. Adjacent the cutting edges, the side surfaces have main flanks extending along the respective cutting edge in a continuously convexly curved manner from one cutting corner to an adjacent cutting corner. The main flanks extend in the direction of the lower side only over part of the height of the side surfaces and merge in a stepped manner into secondary surfaces which are set back inward.