| 摘要 |
PCT No. PCT/DE96/00868 Sec. 371 Date Feb. 4, 1998 Sec. 102(e) Date Feb. 4, 1998 PCT Filed May 8, 1996 PCT Pub. No. WO96/35856 PCT Pub. Date Nov. 14, 1996Drilling tool with a drill head with an end face pointing in the feed direction and which has a main bit, which forms a drill point located in the drill axis and the bit is inclined on either side in a substantially roof-shaped manner and the tool has drilling dust grooves. The main bit has a primary cutting edge, which extends radially over at least one side of the main bit, and a secondary cutting edge, which extends radially over substantially the remaining length of the main bit and is axially set back with respect to the primary cutting edge counter to the feed direction by at least the amount of feed in millimeters per revolution. |
