... 2,Copper plated,Zinc plated 3,Material:low carbon steel tube 4,Use:auto brake assembly O.D(mm) Thickness(mm ... 7 12.700.71,Use:automobile brake system2,Standard:ASTM,DIN,UNI,GB3,Material:low carbon steel tube4,Copper plated ... or Zinc plated5,Wall thickness:0.5mm~0.7mm6,Outer diameter:3.18mm~12mm Auto ... Metal Brake Tube