Tapping screws are threaded fasteners with unique ability to "tap" their own mating internal thread when driven into performed holes in metallic and non-metallic materials. apping screws are high strength, one-piece, one-side-installation fasteners. Self-tapping is the ability of a screw to advance when turned, while creating its own thread. This ability is sometimes created by a gap in the continuity of the thread on the screw. These edges cut a thread as the screw is driven in to the material. The cutting edge drills away the material, leaving a hole for the screw to go into.