Stainless steel is the generic name for a number of different steels used primarily for
their resistance to corrosion. The one key element they all share is a minimum percentage
of chromium: 10.5%. Although other elements are added to improve corrosion resistance,
chromium is always present. The principal grades are austenitic (typically 16-26%Cr,
6-22Ni); ferritic (10.5-28%Cr with no/low Ni); martensitic (higher carbon content than
ferritic and typically 12-19%Cr with low/no Ni); and duplex, a dual-phase austenitic/ferritic
steel (Cr>21%, Ni <8%).
Its many varied applications include food production and storage equipment, pumping and
storage of oils, gases and acids, specialist components in the automotive industry,
cutlery, surgical instruments and fasteners.