| 摘要 |
The invention relates to a countersunk head screw comprising a cylindrical shaft (2) and an essentially conical countersunk head (4) comprising at least two edges (15) on the lower side. Said countersunk head screw is characterised in that the edges each mark an end of a partial surface (10) located on the lower side, each of the partial surfaces lying on a non-concave separate surface of revolution. |
