| 摘要 |
A core cutter allowing the free setting of the thickness of a base body and the easy formation of garrets, wherein each of the blade parts (2) of the core cutter is formed of a chip body and a first cutting blade (2a) disposed on the inner diameter side, a third cutting blade (2c) disposed on the outer diameter side, and an intermediate second cutting blade (2b) are shifted in the order of the first to third cutting blades so that the circumferential positions thereof are located rearwards in that order in the rotating direction. A wall surface (3b) at the rear end of a discharge groove (3) formed correspondingly to the face (2k) of the third cutting blade is formed to be positioned at the same position as that of the blade part (2) or at the rear side thereof in the rotating direction. Each of the garrets (4) having a single surface formed by cutting the tip part outer peripheral surface of the base body (1) so that the inner diameter side thereof leads to the first cutting blade and is projected from the outer diameter side to the tip thereof is formed adjacent to the front part of each of the blade parts in the rotating direction. |
