US Patent 7326014 Interactive fit screw thread

A threaded fastener includes a curved-line path thread provided in a helical pattern along a shank of the fastener. The curved-line path can be provided on either side of the standard straight-line path or on opposite sides of the straight-line path. The curved-line path and can be provided on all or a portion of the thread from near the tip end thereof to near the head end thereof.