| 摘要 |
New system for holding and tightening screws, comprising a screw head with a mortise hole (1) which is bevelled in the screw axis and is provided with a plurality of lugs (2) and corresponding circular sections (3), a tip (4) of a screw-driver or tightening tool with a plurality of wings (5) corresponding to the number of lugs and a tooling set intended to obtain said mortise (1) in the screw head and said tip (4) of screw- driver or tightening tool. |
