AK Steel 439 LT is a ferritic stainless steel that outperforms Type 409 in both oxidation resistance and corrosion resistance, and is comparable to Type 439 stainless steel. Special attention to chemical composition combined with special processing give this alloy optimum formability that is reproducible, coil after coil and heat after heat. This provides special advantages when producing difficult-to-form exhaust systems components. The lower titanium content of AK Steel 439 LT Stainless Steel compared to Type 439 provides an improved surface essentially free from titanium scale.

Oxidation resistance and corrosion resistance superior to Type 409 stainless steel make AK Steel 439 LT Stainless Steel attractive for numerous automotive exhaust applications. Suggested applications include tubular manifolds and other exhaust system areas where temperatures may exceed the oxidation limit of Type 409 or where wet corrosion resistance, particularly to chlorides, is needed.