Self-threading screw for metal with six formers of prismatic shape

摘要

Described herein is a self-threading screw, designed to be inserted in a hole of appropriate size made in a sheet of metal (or other metallic body), which has at the free end of its shank (1) six projections (2) ("formers" or "shapers") of prismatic shape designed to thread by rolling the wall of the hole in which the screw itself is inserted.