(25) 5/16-18 X 1-1/2 Filettatura Vite da Taglio Tipo F F Flangia Esagonale Sems Autofilettante
5/16-18 X 1-1/2 Thread Cutting Screw Type F Hex Flange Sems Self Tapping (MADE IN USA). Because these screws possess almost twice the strength of ordinary machine screws much smaller screws can be used.