Lincoln Electric SuperArc 0.025 in. L-56 MIG Welding Wire 2 lb. is a great choice for welding on metals with a medium to high presence of mill scale. It is copper-coated carbon steel wire with high silicon and manganese deoxidizer levels. Shielding gases include argon and carbon dioxide blends, argon and oxygen blends, straight carbon dioxide, and 3- or 4-part gas mixes.