Our Machine Screws in TYPE 316 Stainless Steel are excellent for use in high corrosion enviroments. Make Sure that you are getting the proper alloy that you are paying for. Most of these screw will have a "DIMPLE" or a "DOT" to help verify the proper alloy! Type 316 contains slightly more nickel than 304 and 2-3% molybdenum giving it better resistance to corrosion than 304, especially in chloride environments that tend to cause pitting. It offers superior performance when exposed to sea water and resists corrosion in sulfuric acid compounds. This Material is best used where exposed to DIRECT salt spray and chemicals.