| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a drill head capable of preventing occurrence of a spiral mark in a hole inner peripheral surface in forming a through-hole on a cutting object material as a drill head including a brazing type cutting blade, and providing excellent external appearance and high processing accuracy. <P>SOLUTION: In this method of manufacturing a drill head 1A including an outer periphery-side cutting blade 3A, an intermediate cutting blade 3B and a center-side cutting blade 3C formed by brazing of cutting blade chips 30A-30C each formed of a sintered hard material, respectively, a cutting blade chip provided with a cutting margin 32 on an outer edge side is used as the cutting blade chip 30A for the outer periphery-side cutting blade 3A; the cutting blade chip 3A is brazed to a cutting blade mounting seat 13a of a body part 10, and thereafter the outer edge side of the cutting blade chip 30A is linearly polished and removed by the first-stage polishing work to set an outer edge part 33 of the outer periphery-side cutting blade 3A; and then the outer end side of the outer periphery-side cutting blade 3A is polished and removed in a round shape by the second-stage polishing work to form a cutting edge outer end 31a having a round shape R. <P>COPYRIGHT: (C)2012,JPO&INPIT |
