A403 Stainless Steel covers the standard for wrought austenitic stainless steel fittings for pressure piping applications. The material for fittings shall consist of stainless steel forgings, stainless steel bars, stainless steel plates, or seamless or welded stainless steel tubular products. Stainless Steel forging or shaping operations shall be performed by hammering, pressing, piercing, extruding, upsetting, rolling, bending, fusion welding, machining.