904L Stainless Steel Tubes also offers good resistance to other inorganic acids such as hot phosphoric acid as well as most organic acids. Stainless Steel 904L Heat Exchanger Tubes was originally developed to withstand environments containing dilute sulfuric acid. The addition of copper to SS 904L Electropolish Tubes gives it corrosion resistant properties superior to the conventional chrome nickel stainless steels, in particular to sulphuric, phosphoric and acetic acids. Stainless Steel 904L Rectangular Tubes contains high amounts of expensive ingredients, such as molybdenum and nickel. Stainless Steel 904L Square Tubes is non-magnetic, and offers excellent formability, toughness and weldability. Stainless Steel 904L Round Tubes is also resistant to stress corrosion cracking and crevice corrosion. SS 904L ERW Tubes is added with copper to improve its resistance to strong reducing acids, such as sulphuric acid.