... easy operation. Screw making machine, bolt making machine, cold former, rivet making machine Features:1. Used as one die two blow ... of two die four blow former), screw drawing machine, hollow rivet making machine. 2.Unique and patent technology of non-clamp ... easy to operate.Range of products:Ordinary screw, hexagon head screw, hexagon with washer screw, step screw series, precise screw series, axle ...