Carbon Steel Welding Wire ER70S-6, .023", 33 LBS Spool. Spool comes in box. 48 rolls available. ER70S-6 MIG welding wire is suitable for welding steel that is dirty, oily, or rusty or steel that has moderate levels of mill scale on the surface. It produces smooth weld beads, making it well suited for welding sheet metal. This wire is typically used in general fabrication, automotive, and pipe welding applications.