| 摘要 |
The present invention is provided with: a ceramic end mill main body (2); chip discharge grooves (4) formed in an outer periphery of the end mill main body (2); outer peripheral cutting edges (6) formed at intersecting ridge lines between wall surfaces which face in a tool rotation direction (T), in the chip discharge grooves (4), and an outer peripheral surface of the end mill main body (2); base cutting edges formed at intersecting ridge lines between the wall surfaces in the chip discharge grooves (4) and a tip end surface of the end mill main body (2); and corner cutting edges which are located in tip end outer peripheral portions of the end mill main body (2), connect the outer ends of the base cutting edges with the tip ends of the outer peripheral cutting edges (6), and are formed in the shape of convex curved lines which have a convexity facing toward the tip end outer peripheral side of the end mill main body (2). From among the outer peripheral cutting edges (6), the base cutting edges and the corner cutting edges, a radial rake angle (angle α) of at least the outer peripheral cutting edges (6) is set to a negative angle. The radial rake angle (angle α) of the outer peripheral cutting edges (6) is between -20° and -10°. |
