| 摘要 |
<P>PROBLEM TO BE SOLVED: To reduce the problem in a throwaway type drill that machining accuracy in the radial direction is deteriorated by positional deviation in the radial direction of a cutting insert for an outer peripheral side during drilling. Ž<P>SOLUTION: This drill includes a substantially rod-like holder, and two cutting inserts each having a cutting blade and fixed to the holder by a screw member. The holder includes a first insert pocket provided at the tip end side and to which one cutting insert is attached, and a second insert pocket provided at the tip end side and further on the inner peripheral side of the first insert pocket, and to which the other cutting insert is attached. The first insert pocket has a first rear end side restraining face abutted on a side face of the one cutting insert positioned at a rear end side of the holder out of side faces thereof. The screw member is rotated in the direction for pressing the outer peripheral side of the one cutting insert out of the side faces thereof toward the first rear end side restraining face in top view of the one cutting insert and fixes the one cutting insert to the holder. Ž<P>COPYRIGHT: (C)2010,JPO&INPIT Ž
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