... ,GB 2,Use:auto evaporator 3,Material:low carbon steel tube 4,Copper coated,Zinc coated O.D(mm) Thickness(mm ... .000.7 12.700.71,Use:automobile brake system,condenser, evaporators.2,Standard:ASTM,DIN,UNI,GB3,Material:low carbon steel ... .5mm~0.7mm6,Outer diameter:3.18mm~12mm evaporator steel tube in car