Forged Steel Socket Welding & Screw Fittings & Pipe Nipples Carbon Steel : ASTM A105, ASTM A106 GR B Stainless Steel (AUSTENITIC) : ASTM A182 GR F304/L ASTM A182 GR F316/L Class Designation : 3000, 6000 Dimensional : ASME B16.11,ANSI/ASME B1.20.1