1) Carbon steel flange 2) Stainless steel flange 3) 20#, A105, Q235A, 12Cr1MoV, 16MnR, 15CrMo,321,304,304L, ... , 16MnR, 15CrMo,321,304,304L,316,316LExample:ANSI B16.5 FORGED FLANGESslip-on flanges, welding neck flanges, socket welding flanges, threaded ...