| 摘要 |
This drill tip performs drilling when attached to the leading end of a drill bit, and comprises a tip main body and a hard layer which is coated on at least the leading end of the tip main body and is formed from a hard diamond sintered body harder than the tip main body, wherein, from the surface side to the tip main body side of the hard layer, the hard layer comprises at least two high-hardness layers and, arranged between said high-hardness layers, a low-hardness layer which has a hardness lower than that of the high-hardness layers. |
