... Standard:ASME,BS,GOST,etc API,ISO,CE,etc pipe fittingsSize -- Seamless:from 1/2" to 24" ,Welded:from 24 ... Q235A, 20G,16Mn, DIN St37, St45.8, St52.4,St.35.8,St.35.8 ASTM A333 GR.6 ; API 5L ... GRB, X60, X65, X42,X52, ectStainless Steel --ASTM A403 WP304,304L,316,316L ... construction, etcSpecial design available as the requirement of customer] seamless pipe fittings SCH40