| 摘要 |
The drill bit has a drilling head, drill shaft (10) and feed lands formed by at least two spiral swarf grooves (16, 18) with webs (20, 22) between them. The non-head end (12) fits in a chuck. Two swarf grooves, at least in the region of the end of the shaft facing the drilling head, have the same identical clear cross section and are at an angle of 130-170 degrees to each other. |
