Specifications ASTM B366 / ASME SB366 Dimensions ASME/ANSI B16.9, ASME B16.28, MSS-SP-43 Size Seamless Butt Weld Fittings: 1/2â?³ â?? 10â?³, Welded Butt Weld Fittings: 1/2â?³ â?? 48â?³ Type Seamless / Welded / Fabricated Schedule Sch 5 TO Sch XXS. Thickness 20 Swg., 18 Swg., 16 Swg., 14 Swg., 12 Swg., 10 Swg., & Sch. 10, Sch. 40, Sch. 80 etc.