Gas Tungsten Arc Welding (GTAW) WELD 250 Practice Test

In these filler-metal designations, the letter after the alloy number signals the product form. In ER480S-2, the S denotes a solid filler metal, meaning it is a solid wire without flux or other cores. The rest of the designation describes the alloy family and version, but the S itself is about the form of the filler, not about being stainless, stabilized, or simply “steel.” So the best answer is that the S indicates a solid wire.