| 摘要 |
The invention relates to a hole-forming and thread-forming screw comprising a head provided with a tool receiving element, in addition to a threaded shaft, and a hole-forming part tapering off in the form of a cone and ending in a truncated end piece. Said end piece has a coaxial recess surrounded by an edge that has an outer diameter (d) which is between 0.25 and 0.75 times smaller than the largest diameter (D) of the hole-forming part.
|
