You say that Emperor and Vulcan cleats are produced in 316L Stainless steel. What is the difference between 316, 316L, 304 and 304L stainless steels?
304 and 316 are both similar austenitic stainless steels, which are designed to withstand corrosion. 316 is the superior grade because it contains molybdenum, which enhances its resistance to corrosion and makes it appropriate for use in a marine environment. There is a simple test, which may be carried out to determine whether molybdenum is present in a particular sample of steel. The importance of using 316L rather than 316 stainless steel, relates to the corrosion resistance of the steel after welding. Stainless steel resists corrosion because it forms an impervious oxide layer on its surface, which heals itself when oxygen is present. When stainless steel is welded, chromium carbide may precipitate at the grain boundaries. This depletes the chromium within the austenite and prevents the passive oxide layer being formed. Because the grain boundaries are small and highly anodic, rapid corrosion occurs. This process can be prevented by using steels with a carbon content of less than 0
