| 摘要 |
PROBLEM TO BE SOLVED: To provide a cylindrical drilling tool which prevents abrasion and deformation of a cylindrical part by cutting chips and a chipped part of a cutting edge, by minimizing a rake angle in the radial direction. SOLUTION: The cylindrical drilling tool has: a cylindrical part 22 having the axis; and a cutting tip 1B arranged in a tip part of its cylindrical part and having the cutting edge in the tip part, and drills a machinable material by rotating around the axis. The tool also has a breaker part arranged in a predetermined position on a rake face corresponding to an effective cutting edge range of the cutting edge, that is, the breaker part having a guide part extending in the substantially axial direction from the tip part of the cutting tip and a deflection part extending from a rear end side end part of the guide part and rising in the substantially circumferential direction of the cylindrical part. COPYRIGHT: (C)2008,JPO&INPIT
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