standard:ANSI, DIN,JIS, BS and UNI carbon steel stainless steel and alloy steel cap Standard: Standard: GB /ASTM / ASME / DIN / JIS.Material ... :Carbon steel(10#, 20#, Q235, 20G, 16Mn, ASTM A234, ASTM A105, ST37 ... ),Stainless steel (TP304, TP304H, TP304LN, TP304L, TP310 / S, TP316L, TP316H, TP316 / 316L, TP317L, TP321 / 321H).Size: 1/2"-36" Seamless; 1 ...