| 摘要 |
The method involves cutting a conical, preferably hollow, seat for the drill. The seat may be formed by high speed milling or by electrical eroding. The surface of the system may be made coarse with ribbing or teeth, preferably at a microscopic level. A drill bit and a drill shaft are then fixed on the seat and joined by hard soldering. The drill bit may have a complementary conical counter part that fits in the seat. An independent claim is included for a drill. |
