Self Tapping Screws DIN7971, DIN7972, DIN7973, DIN7981, DIN7982, DIN7983 ASME B18.6.4 & SAE J933 specifications Self Tapping ScrewsDIN7971, DIN7972, DIN7973, DIN7981, DIN7982, DIN7983 ASME ... self tapping screws: thread forming, thread cutting, and thread rolling.Specifications: Head: Pan head, Flat head, Indented hex head, Indented hex washer head, Serrated hex washer head, Truss head, Oval head ...