Lincoln's premium copper coated MIG wire, SuperArc L-56 is an excellent choice on metals with a medium to high presence of millscale. For best performance use on clean, oil-free, and rust-free base material. Best weld appearance and toe wetting when compared to ER70S-3 and ER70S-4 classifications. SuperArc L-56 has high silicon and manganese deoxidizer levels. Superior feedability and excellent arc characteristics are trademarks of SuperArc L-56.