1) Carbon steel flange 2) Stainless steel flange 3) 20#, A105, Q235A, 12Cr1MoV, 16MnR, 15CrMo,321,304,304L, ... neck flanges, socket welding flanges, threaded flanges, lap joint flanges, blind flangesDIN2512, DIN2513, DIN2514, DIN2519, DIN2566, DIN2573, DIN2576, DIN2530, DIN2627, DIN2628 ...