Weldmark by Lincoln ER70S-6 MIG mild steel welding wire with its higher levels of manganese and silicon deoxidizers is tolerate when welding medium up to heavy mill scale surfaces. Typical applications include general shop where there is poor fit-up or when used on rusty, oily plates, steel castings or forging salvage. It is also very good for home projects, on sheet metal, tanks and construction work. The high silicon content increases the fluidity of the weld pool creating a smoother bead appearance, resulting in minimal post-weld grinding. The diameter on this item is .035" (0.9mm) and is packaged on a 33 pound wire spool.