Throw-away insert and milling cutter using such a throw-away insert

摘要

A throw-away insert 1 includes: an upper surface 2; a bottom surface 3; two side surfaces 4, 4 formed with upper side surfaces 4a and lower side surfaces 4b; two end surfaces; four nose sections formed at the corners of the upper surface 2; a main cutting section 6 formed from a ridge line positioned at the intersection between the upper side surface 4a and the upper surface 2; a secondary cutting section formed from a linear ridge line positioned at the intersection between the end surface and the upper surface; and an axial support surface formed from a section of the end surface. The upper side surface 4a is projected outward more than the lower side surface 4b.