WERKWIJZE VOOR HET ROLLEN VAN DE SCHROEFDRAAD VAN EEN ZELFTAPPENDE SCHROEF.

摘要

A self-thread forming threaded fastener is disclosed having a straight thread on a shank of circular cross section and a tapered thread on the work-entering end. The tapered portion of the thread is of lobular root, pitch and crest surface cross sections and which lobular configuration is continued, but to a diminishing extent, on the first few threads on the shank section immediately adjacent the tapered section.