A self-tapping screw includes a head and a shank extending from the head. The shank includes a cylindrical shank immediately below the head and a truncated conical shank following an end of the cylindrical shank. The cylindrical shank is provided with a plurality of first external threads, the truncated conical shank is provided with a plurality of second external threads following the first external threads, and a peak of each of the second external threads is provided with a biting surface having a concave-convex form.

A screw anchor and method of forming such a screw anchor, the method comprising: forming a first male screw thread section on a metallic body and which is integral to the metallic body; and using a metal deposition technique to deposit a second male screw thread section on the metallic body; wherein the second male screw thread section is formed of metallic material having a greater hardness than the metallic body and is able to tap out a female thread in a hole in a support for receiving the first male screw thread section when the screw anchor is twisted into the hole.