Stainless steels are iron based alloys containing at least 10.5% chromium. They achieve their stainless characteristics through the formation of an invisible and adherent chromium rich oxide film. Alloy 316 is a general purpose austenitic stainless steel with a face centered cubic structure. It is essentially non-magnetic in the annealed condition and can only be hardened by cold working. Molybdenum has been added to increase corrosion resistance particulary in chloride containing enviroments. The lower carbon content of alloy 316L gives even better corrosion resistance in welded structures.