| 摘要 |
Screw-driver blade or screw-driver bit with a long-wearing working point. The blade or bit is made of tough steel with a hardness degree between 45 and 60 on the Rockwell C scale, whereby the working point is coated with a 1.5 to 5.0 mu m-thick layer of TiN or TiC. The advantage of the present invention is that, because of the tough steel used for the blade or bit, the blade or bit does not brake in the event of sudden peaks in load. Because of the surface coating, the working tip is also very resistant to wear and therefore dimensionally very stable. |
