... in accordance with a screwdriver.l Multiple spindle automatic locking screw machine, 2- spindle , 3- spindle , 4- spindle , 5- spindle …all of this can be customized ... .0mm-M8.0mmthread length 4 - 25mm,thread length >= Head diameter2mmthread length 4 - 25mm,thread length >= Head diameter2mmHead diameter3.0 - 8,0,Head diameter >= 1.3times ...