US Patent 8403972 Thread-forming screw

A thread-forming screw includes a screw end, a shank, and a thread-free head, wherein the shank is provided at least partly with a thread and has a pre-forming region, an intermediate region, which is arranged to follow the pre-forming region, and an anchoring region, which is arranged so as to adjoin the intermediate region and below the head, wherein the pre-forming region is arranged so as to directly adjoin the screw end.