Specifications ASTM B366 ASME SB366 Dimensions ASMEANSI B169 ASME B1628 MSSSP43 Size Seamless Butt Weld Fittings 12 10 Welded Butt Weld Fittings 12 48 Type Seamless Welded Fabricated Schedule Sch 5 TO Sch XXS Thickness 20 Swg 18 Swg 16 Swg 14 Swg 12 Swg 10 Swg amp Sch 10 Sch 40 Sch 80 etc