| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a finishing end mill capable of effectively restraining generation of a cutter mark, by improving processing surface roughness more than conventional processing surface.SOLUTION: The finishing end mill comprises a blade part 4 having an outer peripheral blade 11 formed by projecting outside in the radial direction from a core thickness circumferential surface 6 and a bottom blade 16 formed on a tip surface, and the bottom blade 16 comprises a bottom blade flank 14 for forming a bottom second primary cutting edge 12 and a bottom second secondary cutting edge 13 inward in the radial direction from the adjacent side of the outer peripheral edge 11, and assuming a concave angle of the bottom second primary cutting edge 12 asαand a concave angle of the bottom second secondary cutting edge 13 asβ, the angles are set so as to becomeα<β, and at least one of a corner edge 7 of a boundary part with the outer peripheral blade of the bottom second primary cutting edge 12 and a radius edge 8 of a boundary part between a rake face 19 of the bottom blade second flank 14 and the bottom second primary cutting edge 12, is formed as a round surface R on a circular arc having predetermined curvature.</p> |
