Lincoln Electric SuperArc 0.030 in. L-56 MIG Welding Wire 2 lb. is copper-coated MIG wire that is great for welding on metals with a medium to high presence of mill scale. It works best on clean, oil-free and rust-free base material. It has 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.