For use in marine and automotive applications, our Stainless Steel 321 Electropolish Tubes are 100 % stainless steel and are available with varying tensions. Stainless Steel 321H Rectangular Tubes is often used in Chemical and petrochemical process equipment, pulp and paper manufacturing and condensers in fossil and nuclear fueled power generation stations. SS 321 Square Tubes is molybdenum bearing grade austenitic stainless steel that provides improved corrosion resistance over 304L and 316L stainless steels. Stainless Steel 321H Round Tube does not perform well in chloride solutions, even in small concentrations, or in sulfuric acid service. In order to provide optimum resistance in SS 321 ERW Tubes to intergranular corrosion and to polythionic acid stress corrosion cracking in service temperatures at 1500°-1650°F an air cool may be used. This titanium addition in Stainless Steel 321H EFW Tubes reduces or prevents carbide precipitation during welding and in the 800°-1500°F service conditions.