The term 'corrosion resistant steel' is used when the alloy has less than the 12% minimum of chromium, for example in the aviation industry. There are different grades and surface finishes of stainless steel, depending on where it will be used. Stainless steels have a higher resistance to oxidation (rust) and corrosion in many natural and man-made environments, Different stainless steels have different amounts of different metals in them, and they are good for different purposes. There are over 150 grades of stainless steel, of which fifteen are the most used. 