UNS S32205, S31803 Duplex Stainless Steel Fittings is an austenitic-ferritic stainless steel with superior corrosion resistance and high strength. It has good solderability and can be soldered by a variety of methods. Grade 1.4462 (also known as UNS S31803/S32205, F51 and SS2377) fittings are a stainless acid resistant duplex steel with high strength and excellent corrosion properties.