Hexagon second punch of Heading Dies for Hexagon head screws, inluding self tapping screw & self drilling screws, etc. Work with one die two blow heading machines. Manufacturing steps to make self drilling screw with washer: Finished wire -- Heading -- Self Drilling Screw Point Forming -- Thread Rolling -- Heat treatment -- Surface treatment -- Screw Washer Assembly -- Packing We Airon Machinery supply full line equipment for self drilling screw manufacturing, including Heading Machine, Thread Rolling Machine, Self Drilling Screw Point Forming Machine, Screw Washer Assembly Machine, Heat treatment equipment etc.