Abstract: A cutting insert according to one aspect of the present invention includes a polygonal columnar shape, and includes an upper surface, a lower surface and a side surface located between the upper surface and the lower surface, and a cutting edge is formed at an intersecting portion between the upper surface and the side surface, the upper surface includes a main portion of a convex shape including a flat upper end surface, a first projecting portion which projects from the main portion to a corner portion of the upper surface, and a pair of second projecting portions which each project from the first projecting portion to a periphery of the upper surface to interpose a region between a front end of the first projecting portion and the corner portion, and each of upper ends of the pair of second projecting portions is spaced part from the first projecting portion.

Abstract: A cutting insert has a polygonal columnar shape and includes an upper surface, a lower surface, a side surface located between the upper surface and the lower surface, and a cutting edge formed at an intersection of the upper surface and the side surface. The upper surface includes a convex-shaped main part including a flat upper end surface, a first projection projecting from the main part to a corner part of the upper surface, a second projection projecting from the first projection toward the corner part, and a pair of third projections respectively projecting from the first projection toward a periphery of the upper surface that interpose at least a part of the second projection between the pair of third projections. A surface of the first projection is an inclined surface curved in a concave shape, and a surface of the second projection is a planar inclined surface.

Abstract: A cutting insert has a polygonal columnar shape and includes an upper surface, a lower surface, a side surface located between the upper surface and the lower surface, and a cutting edge formed at an intersection of the upper surface and the side surface. The upper surface includes a convex-shaped main part including a flat upper end surface, a first projection projecting from the main part to a corner part of the upper surface, a second projection projecting from the first projection toward the corner part, and a pair of third projections respectively projecting from the first projection toward a periphery of the upper surface that interpose at least a part of the second projection between the pair of third projections. A surface of the first projection is an inclined surface curved in a concave shape, and a surface of the second projection is a planar inclined surface.

Abstract: A cutting insert according to one aspect of the present invention includes a polygonal columnar shape, and includes an upper surface, a lower surface and a side surface located between the upper surface and the lower surface, and a cutting edge is formed at an intersecting portion between the upper surface and the side surface, the upper surface includes a main portion of a convex shape including a flat upper end surface, a first projecting portion which projects from the main portion to a corner portion of the upper surface, and a pair of second projecting portions which each project from the first projecting portion to a periphery of the upper surface to interpose a region between a front end of the first projecting portion and the corner portion, and each of upper ends of the pair of second projecting portions is spaced part from the first projecting portion.

Abstract: A cutting insert according to an embodiment of the present invention includes an upper surface; a side surface; and a cutting edge located at an intersection region of the upper surface and the side surface. The upper surface includes a rake surface continuous with the cutting edge; and a rising surface inclined and lying at a higher position as going inward from the rake surface. The rake surface includes a pair of first raised parts respectively extending inward from near both ends of the cutting edge in a top view; and a second raised part extending from one of the pair of first raised parts to the other. A cutting tool including the cutting insert, and a method of manufacturing a machined product by using the cutting tool are also provided.

Abstract: A cutting insert according to an embodiment of the present invention includes an upper surface; a side surface; and a cutting edge located at an intersection region of the upper surface and the side surface. The upper surface includes a rake surface continuous with the cutting edge; and a rising surface inclined and lying at a higher position as going inward from the rake surface. The rake surface includes a pair of first raised parts respectively extending inward from near both ends of the cutting edge in a top view; and a second raised part extending from one of the pair of first raised parts to the other. A cutting tool including the cutting insert, and a method of manufacturing a machined product by using the cutting tool are also provided.