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, 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 cutting insert, a cutting tool and method of manufacturing a machined product. The cutting insert includes: upper and lower surfaces; a side surface; a cutting edge; and a rake portion on the upper surface. The cutting edge includes major and minor cutting edges that are convex toward outside of the main body portion. The minor cutting edge has a curvature radius smaller than a curvature radius of the major cutting edge. The rake portion is inclined and approaches the lower surface as moving from the major cutting edge toward inside of the main body portion and is located along the major cutting edge. An inclination angle of the rake portion becomes smaller as moving from a part continuous with one end of the major cutting edge toward a part continuous with center of the major cutting edge.

Provided is a cutting insert capable of suppressing edge fracture when a work having high hardness is machined. A cutting insert includes two end surfaces having a plurality of corner parts and opposed to each other, a peripheral side surface extending between the two end surfaces, and a cutting edge formed at an intersecting edge between at least one of the two end surfaces and the peripheral side surface. The cutting edge has at least a first corner edge, a second corner edge, a major cutting edge, and an end cutting edge. The end cutting edge has a circular-arc shape, which projects outward, as viewed from the side of the end surface. The end cutting edge has a width which is from 15% to 50% of the width of the cutting insert. The end cutting edge has an arc radius which is from to 1/1 of the width of the cutting insert.

A cutting edge configuration of a cutting tool for performing a cutting process on a surface (21) of a workpiece (19), the cutting tool including a rake face (3) provided with first and second cutting edges (11, 13), the cutting tool being moved relative to the surface-to-be-cut (21) with the first and second cutting edges (11, 13) cutting thereinto to thereby perform the cutting process, wherein the first cutting edge (11) is positioned ahead of the second cutting edge (13) in a cutting direction (z-direction) of the cutting tool to provide the rake face (3) with a feed-direction (y-direction) rake-angle, and the cutting tool is fed in a direction from a side of the second cutting edge (13) to a side of the first cutting edge (11).

In a cutting insert of an embodiment of the present invention, an upper surface includes a first corner, and a second corner and a third corner respectively adjacent to both sides of the first corner. The upper surface sequentially includes a rake surface located along an upper cutting edge and inclined toward a lower surface as going inward from the upper cutting edge at a rake angle on a basis of a perpendicular plane perpendicular to a central axis extending between the upper and lower surfaces, and a connection surface located more inward than the rake surface and inclined toward the lower surface as going inward at a connection angle on the basis of the perpendicular plane. An intersecting part of the rake surface and the connection surface includes a highest position in a portion of the intersecting part corresponding to the minor rake surface. A cutting tool with the cutting insert, and a method of producing a machined product by using the cutting tool are also provided.

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 cutting insert for machining has a substantially cylindrical main body with an axis, a lateral flank and opposing rake faces. Cutting edges are formed at the intersection of the flank and rake faces. The cutting edges have, in the direction of the axis, in each case at least two convexly curved sections which are connected together by concavely curved or substantially straight sections.

A double-sided, indexable cutting insert for a milling cutter includes a first surface, a second surface, and side surfaces. Major cutting edges are defined at an intersection between the first and second surfaces and side surfaces. Minor cutting edges and ramping cutting edges are defined at the intersection between the first and second surfaces and side surfaces. The cutting insert is mounted in a milling cutter having a bottom seating surface formed at an angle with respect to a central, rotational axis of the milling cutter, which provides superior performance for both milling and ramping cutting operations.

A cutting insert is used in a cutting edge replaceable rotary cutting tool. The cutting insert includes a first cutting edge formed on an intersecting ridge portion between a first end surface of two opposite end surfaces and a circumferential side surface, and a first depressed portion formed along a part of the first cutting edge. The first depressed portion is provided to form a larger rake angle at the first cutting edge than that at a part not having the first depressed portion of the first cutting edge.

A cutting insert comprises an upper surface including a first corner, and a second and third corner, respectively, adjacent to both sides of the first corner. The upper surface sequentially includes a rake surface along an upper cutting edge, inclined toward a lower surface, going inward from the upper cutting edge at a rake angle on a basis of a perpendicular plane perpendicular to a central axis extending between the upper and lower surfaces, and a connection surface more inward than the rake surface, inclined toward the lower surface, going inward at a connection angle on the basis of the perpendicular plane. An intersecting part of the rake surface and the connection surface includes a highest position in a portion of the intersecting part corresponding to a minor rake surface. A cutting tool with cutting insert, and a method of producing a machined product using the cutting tool are provided.