Stainless steel flange not only refers to a kind of stainless steel flange, but also represents more than 100 kinds of industrial stainless steel flanges. Each type of stainless steel has good performance in its specific application field. First, the purpose of flange shall be clarified, and then the correct stainless steel grade shall be determined. Common stainless steels are 304, 304L, 316, 316L, etc. They all contain chromium, nickel and other chemical components. For example, the addition of molybdenum can further improve the atmospheric corrosion, especially the corrosion resistance to the atmosphere containing chloride.