Hi Every one: Stainless Steel is corrosion resistant because of the Chrome content in it's formulation. Type 316 has about 16.5 % Chrome, 12 % Nickle, 2.5 % Molybdenum, 2% Manganese, 1 % Silicon, 0.03 % Carbon in an Iron solution. A steel cannot qualify for the stainless prefix untill it has at least 10.5% chromium. The Chrome migrates to the surface during processing and forms an oxide that is extremly corrision ressistant. This is the same reason the bumpers on cars stay the way they do and why I wished I had the money to buy a stainless extractor. James Peterson Ph. D. Chemistry Teacher