... .5, GOST, EN1092-1, HG, UNI, JIS, NFE, GB, BS... 2. Material: 1.4301, 1.4307, 1.4401, 1.4404, 1.4541, 1.4571, 1.4305, 1.4539, F44, F51 ... , duplex flange and alloy steel flange, which can be used in pharmacy, tube, pipe industry, oil and gas industry, space, machinery accessory etc... slip on flange