Grade 904L is a non-stabilised low carbon high alloy austenitic stainless steel. The addition of copper to this grade gives it greatly improved resistance to strong reducing acids,particularly sulphuric acid. It is also highly resistant to chloride attack - both pitting / crevice corrosion and stress corrosion cracking.This grade is non magnetic in all conditions and has excellent weldability and formability.The austenitic structure also gives this grade excellent toughness, even down to cryogenic temperatures.