ASTM :A105,A350(LF1,LF2,LF3), DIN:C22.8,C21,RST37.2 JIS: SS400,SF440A GB: Q235, 16Mn Flanges Type Weld Neck,Slip-On,Blind,Socket Weld,Lap Joint,Threaded,Etc. Size 1/2"-72"Class 150#,300#,400#,600#,900#,1500#,2500# Specification Carbon Steel ASTM A105/A694 F42/46/52/60/A350 LF2 Stainless Steel ASTM A182 F304/304L/316/316L Alloy Steel ASTM A182 F1/F5/F9/F11/F22/F91/Etc.