Patent ID: 7997836
Filing Date: 2011-08-16
Classification: B23B,Y10S,Y10T

Abstract:
1. An indexable type cutting tool comprising: a drill having a shank and a drill body which extends integrally from the shank, the drill body being defined, on a circumferential outer surface thereof, with body flutes, and being formed, at a distal end thereof with an insert seat which has seat side surfaces and a seat bottom surface, and, at both sides of the insert seat, with body flank surfaces and body thinning surfaces which are opposite to each other; a drill insert fitted into the insert seat of the drill body, having at a distal end thereof cutting edges and at an opposite proximal end thereof an insert bottom surface which is brought into close contact with the seat bottom surface, formed between the cutting edges and the insert bottom surface with insert flutes and insert side surfaces which are brought into close contact with the seat side surfaces, and defined with a through-hole which passes through the insert side surfaces; and a fastening screw for fastening the drill insert fitted into the insert seat to the drill; wherein the through-hole is composed of a through-hole roof part, a through-hole bottom part which has a size smaller than that of the through-hole roof part, and through-hole side parts which connect both ends of the through-hole roof part and both ends of the through-hole bottom part with each other; and the through-hole side parts extend such that they radially converge from the through-hole roof part to the through-hole bottom part.