| 摘要 |
PROBLEM TO BE SOLVED: To prevent the relatively early abrasion of a diamondlike material by forming a cutting edge along the front edge part of polycrystalline diamondlike material formed in the groove of a cutter blank. SOLUTION: A groove 18 is formed in the front edge part 15 of each part between flutes 14 provided on the outer periphery of a cutter blank 12. A sintered polycrystalline diamondlike material 30 is formed in a spirally formed groove 18. A cutting edge 32 is formed in the front edge part 15 of the sintered diamondlike material 30 press-processed in the groove 18 adjacent to the flute 14. The cutter blank 12 formed like this is metallic-joined through a joining part 17 to a drill shaft part 16 made of steel or carbide. The metallic joining can be carried out by brazing. |
