Bolt, Nut, Customized Fastener manufacturer / supplier in China, offering ASTM A320 B8 12 Point Flange Head Bolt for Oil Gas, Ifi-115-2002 1-1/2 3-5/8 2-7/8 Zinc Nickle Plated PTFE ASTM A193 B7 Blue Fluorocarbon 12 Point Hex Flange Bolt for Oil&Gas Industry, Ifi-115 A193 B7 12 Point Flange Bolt, Black Oxide, 3/8"-3/4", En 10204 3.1, Oil & Gas Heavy Duty and so on.