RADIUS END MILL AND CUTTING INSERT

摘要

A radius end mill including an end mill body which is rotated around an axis thereof; a chip discharge flute being provided at an outer periphery of a tip portion of the end mill body; a gash being provided at a tip portion of the chip discharge flute; a rake face being formed on a wall face facing an end-mill rotational direction in the chip discharge flute or the gash; a cutting edge being formed on the rake face; the cutting edge including an end cutting edge, an outer peripheral cutting edge, and a convex circular-arc-shaped corner cutting edge; the end cutting edge being formed at a side ridge portion on the tip portion of the rake face; the outer peripheral cutting edge being formed at a side ridge portion on the outer peripheral side of the rake face; the convex circular-arc-shaped corner cutting edge being formed at a corner side ridge portion formed by the end cutting edge and the outer peripheral cutting edge; a chip breaker being formed on a side ridge portion of the rake face at least along the corner cutting edge so as to have a convex circular-arc shape extending parallel to the corner cutting edge at the portion along the corner cutting edge; the chip breaker having a groove bottom face lower than respect to the rake face, and a groove wall face which rises from the groove bottom face and is connected to the rake face; and at both ends of the chip breaker on the side of the end cutting edge and on the side of the outer peripheral cutting edge, the groove bottom face rising to connect with the rake face in a direction along the end cutting edge or the outer peripheral cutting edge at the end, or the groove bottom face extends so as to be parallel to the rake face and the chip breaker is opened.