| 摘要 |
<p>Self-tapping screw comprises a screw head (1), a screw shaft (2) with a thread (4), and a drill tip (3) used as a drill, especially a twist drill, and made of super-speed steel and connected to the screw shaft. Preferred Features: The screw shaft is made of case-hardened steel. The drill tip is welded to the shaft, especially by friction welding.</p> |
