... 1.Material:steel,stainless steel.brass,aluminum,brass.cooper. carbon steel. 2.Surface:zinc plating ,powdered,pas Torsion Bar Spring 1.Material:steel,stainless steel.brass,aluminum ... melting furnace,CNC machine center...8Test Euipmentspectrum analyzer, Physio-chemicalLabora tory 9Production lines1) The lost-wax casting of stainless steel and heat-resisting steel ...