A cutting insert includes a first surface and a second surface each of which is polygonal and that face away from each other; a side surface that is continuous with the first surface and a side surface that is continuous with the second surface; a cutting edge formed along each of a ridge where the first surface and the side surface intersect and a ridge where the second surface and the side surface intersect; a bearing surface formed in each of a part the first surface and a part of the second surface adjacent to an insert center, the bearing surfaces disposed parallel to each other; and a recessed portion that separates the side surface that is continuous with the first surface from the side surface that is continuous with the second surface. The cutting edge includes three corner edges, a first cutting edge, and a second cutting edge, the first and second cutting edges being continuous with each other and located between each pair of the corner edges. A length of the first cutting edge is greater than that of the second cutting edge, an end portion of the first cutting edge adjacent to one of the corner edges is at a position higher than the bearing surface, and an end portion of the first cutting edge opposite to the end portion adjacent to the corner edge is at a position lower than the bearing surface. Each of the first surface, the second surface, and a cross section of the recessed portion has such a shape that outlines of the shape before and after rotation of the insert by 120 around the insert center are coincident with each other. The first surface and the second surface have the same shape, and the second cutting edge of the second surface is located at a corner at which the first cutting edge of the first surface is located.

The present invention provides a tool body (20) for use in an indexable rotary cutting tool, the tool body (20) having a rotational axis and a substantially cylindrical shape. Spiral grooves (28) are formed so as to extend from a base end side of the tool body to a leading end side in a peripheral surface (23) of the tool body. The spiral grooves (28) each have a plurality of insert seats (30) formed so as to be shifted from each other from the base end side toward the leading end side. The insert seats (30) each have a bottom surface (31) and first and second side surfaces (32, 33) that extend so as to intersect with the bottom surface (31). The first side surface (32) faces the base end side of the tool body (20), and the second side surface (33) faces the leading end side of the tool body (20) and is located on the base end side with respect to the first side surface (32). In at least one insert seat (30) located closer to the base end side with respect to an insert seat (30) located closest to the leading end side of the tool body (20), a length (L1) of the first side surface (32) is longer than a length (L2) of the second side surface (33).

A cutting insert includes: a polygonal shaped upper surface; a lower surface; a side surface connected to each of the upper and lower surfaces; and an upper cutting edge located at the intersection of the upper surface and the side surface. The upper surface alternately includes three major corners and three minor corners. The upper cutting edge includes: a corner cutting edge; a minor cutting edge inclined toward the lower surface as separating from the corner cutting edge at a first inclination angle; and a major cutting edge inclined toward the lower surface as separating from the minor cutting edge at a second inclination angle. The corner cutting edge, the minor cutting edge and the major cutting edge are located sequentially from a first major corner to each of first and second minor corners, both of which are adjacent to the first major corner.

A high-feed milling tool assembly includes a tool and a ramping insert. The ramping insert includes ramping, feed and side sub-edges. The ramping and feed sub-edges are longer than the side sub-edges and converge with increasing proximity to the side sub-edge to which they are both connected.

An insert in which a cutting edge is formed only between an upper surface and a side surface. The insert comprises: three or more corners along a perimeter; a main cutting edge formed on an edge between an upper surface and a main side surface, and a sub cutting edge formed on an edge between the upper surface and a sub side surface, wherein the main cutting edge and the sub cutting edge are placed in succession between the corners; and a flat lower surface. The main cutting edge forms an inclination angle such that a height decreases gradually in a direction toward the sub cutting edge. The main side surface is formed by a first end main side surface and a second end main side surface. The sub side surface is formed by a first end sub side surface and a second end sub side surface.

In a cutting insert according to an embodiment of the present invention, an upper cutting edge includes, sequentially from a first corner to a second corner, a corner cutting edge, a minor cutting edge inclined as separating from the corner cutting edge at a first inclination angle on a basis of a vertical plane perpendicular to a central axis extending between upper and lower surfaces, and a major cutting edge inclined as separating from the minor cutting edge at a second inclination angle on the basis of the vertical plane so as to become more closer to the lower surface than the minor cutting edge. A cross section of a rake surface obtained by cutting an inwardly located end portion thereof along a direction of the central axis has a straight line shape or concave shape in a region crossing over at least a minor rake surface and a major rake surface. A cutting tool with the cutting insert, and a method of manufacturing a machined product by using the cutting tool are also provided.

A cutting tool including: a tool body (2) provided with an insert support seat (5) including a major seat surface (5a) that supports a bearing surface of a cutting insert, a plurality of seat side surfaces (5b, 5c) that supports side surfaces of the cutting insert at different positions, and a thinned portion (5d) continuous with the major seat surface and the seat side surfaces; and a cutting insert attached to the insert support seat, wherein a ridge at a position where the major seat surface and the thinned portion intersect, a ridge at a position where the seat side surface and the thinned portion intersect, and a ridge at a position where the thinned portions continuous with each other intersect are each formed of a convex arc curved surface.

A cutting insert includes a first and a second pair of opposing side surfaces. As seen towards a first side surface, a first axial relief face and a first axial abutment face form part of a first surface grouping on a first side of a longitudinal plane. As seen towards a second side surface, a second axial relief face and a second axial abutment face form part of a second surface grouping on the first side of the longitudinal plane. The first axial abutment face forms a substantially flat surface and extends perpendicularly to a median plane of the insert. The second axial abutment face forms a substantially flat surface and extends perpendicularly to the median plane. A second side surface of the first pair of opposing side surfaces has a first and a second radial abutment face.

A cylindrical tool body has a peripheral surface provided with one or more spiral grooves extending from a base end side to a leading end side. The grooves each have a plurality of insert seats which are shifted relative to one another from the base end side toward the leading end side. The insert seats each have a bottom surface, a first side surface of length L1, and a second side surface of length L2. The first side surface faces the tool body's base end side, and the second side surface faces the tool body's leading end side and is located on the base end side with respect to the first side surface. In at least one insert seat located closer to the base end side than an insert seat located closest to the tool body's leading end side, the first side surface is longer than the second side surface.

A cutting insert includes: a polygonal shaped upper surface; a lower surface; a side surface connected to each of the upper and lower surfaces; and an upper cutting edge located at the intersection of the upper surface and the side surface. The upper surface alternately includes three major corners and three minor corners. The upper cutting edge includes: a corner cutting edge; a minor cutting edge inclined toward the lower surface as separating from the corner cutting edge at a first inclination angle; and a major cutting edge inclined toward the lower surface as separating from the minor cutting edge at a second inclination angle. The corner cutting edge, the minor cutting edge and the major cutting edge are located sequentially from a first major corner to each of first and second minor corners, both of which are adjacent to the first major corner.