SELF-TAPPING SCREW FOR USE IN LOW DUCTILE MATERIALS

摘要

The present invention relates to a thread (400) in particular for a thread-rolling or self-tapping screw (100) or nut, respectively, having a non-triangular thread profile (300) with leading thread faces (422) and trailing thread faces (424) wherein at least one of said leading thread faces (422) and trailing thread faces (424) is provided with a convex curvature having a first radius (R). The tip (442) of said non-triangular thread profile (400) has also a convex curvature with a second radius (r1) wherein the value of the first radius (R) is different from the value of the second radius (r1).