Stud Bolt and Nut, Copper Pipe Tube, Spiral Wound Gasket manufacturer / supplier in China, offering API/B16.20 Ring Joint Flange Gasket, ANSI B18.2.1 A193 B7 3/8 Inch Hex Bolt for Oil Pipeline, DIN 931 A193 B7 Xylan Coated Stud Bolt for Oil Pipeline and so on.