Mild Steel Welding Alloy ER70S-2: a premium, multiple deoxidized TIG welding rod produces high quality welds in most grades of carbon steels. E70S-2 is a triple deoxidized wire which provides defect free weld deposits when properly used on most carbon steels. It is used especially for pipe welding. ER70S-2 Conforms to AWS A5.18 ER70S-2.