STEEL COUPLING 1) Materials: 304, 304L, 316, 316L, 321 2) Forming type: mandrel-forming 3) Standards: ASME B16.9,MSS SP-43 Steel Coupling1 ... ) Materials: 304, 304L, 316, 316L, 321 2) Forming type: mandrel-forming 3) Standards: ASME B16.9,MSS SP-43,DIN ... 3409,SH 3409,HG/T 21635,HG/T 21631 4) Sizes: seamless:1/2"-20"(DN15-DN500),SCH5S/10S/40/80/160 welded ...