A cutting tool includes: a body extending along a longitudinal axis between a leading and trailing ends, the body having a clamping region disposed at or about the trailing end and a cutting region which extends toward the clamping region from the leading end of the body; a plurality of flutes defined in the body, each extending from the leading end toward the coupling portion; a plurality of peripheral cutting edges, each extending from the leading end toward the coupling portion along a corresponding flute of the plurality of flutes; and a plurality of end cutting edges disposed at the leading end, each end cutting edge extending from at or near the longitudinal axis outward along a corresponding flute. At least one end cutting edge is defined, in-part, by a plurality of rake faces which each extend from a corresponding portion of the one cutting edge into the corresponding flute.

A cutting tool includes: a body extending along a longitudinal axis between a leading and trailing ends, the body having a clamping region disposed at or about the trailing end and a cutting region which extends toward the clamping region from the leading end of the body; a plurality of flutes defined in the body, each extending from the leading end toward the coupling portion; a plurality of peripheral cutting edges, each extending from the leading end toward the coupling portion along a corresponding flute of the plurality of flutes; and a plurality of end cutting edges disposed at the leading end, each end cutting edge extending from at or near the longitudinal axis outward along a corresponding flute. At least one end cutting edge is defined, in-part, by a plurality of rake faces which each extend from a corresponding portion of the one cutting edge into the corresponding flute.

A cutting insert includes a rake face, a flank surface, and a cutting edge, the cutting edge includes a bottom cutting edge that is positioned at a front end in a central axis direction and forms a convex arc shape and an outer peripheral cutting edge aligned with a radial-direction outer end of the bottom cutting edge and forms a convex arc shape of which a curvature radius is larger than that of the bottom cutting edge, an angle formed between a tangent line to a boundary point between the bottom cutting edge and the outer peripheral cutting edge and the central axis is less than 45, a curvature radius R1 of the bottom cutting edge is 0.3 to 10 mm, and a ratio (R2/R1) of a curvature radius R2 of the outer peripheral cutting edge to the curvature radius R1 of the bottom cutting edge is 3.6 to 333.

A cutting insert includes a rake face, a flank surface, and a cutting edge, the cutting edge includes a bottom cutting edge that is positioned at a front end in a central axis direction and forms a convex arc shape and an outer peripheral cutting edge aligned with a radial-direction outer end of the bottom cutting edge and forms a convex arc shape of which a curvature radius is larger than that of the bottom cutting edge, an angle formed between a tangent line to a boundary point between the bottom cutting edge and the outer peripheral cutting edge and the central axis is less than 45, a curvature radius R1 of the bottom cutting edge is 0.3 to 10 mm, and a ratio (R2/R1) of a curvature radius R2 of the outer peripheral cutting edge to the curvature radius R1 of the bottom cutting edge is 3.6 to 333.