Both 304 and 316 belong to the austenitic stainless steel series. They are roughly similar in terms of product mechanical properties, with the main difference lying in the difference in their corrosion resistance. The corrosion resistance of stainless steel is also conditional; one type of stainless steel may be corrosion-resistant in a certain medium, but may be damaged within a few hours in another medium. Moreover, the corrosion resistance of stainless steel is relative. So far, no type of stainless steel is absolutely corrosion-resistant, nor is any type of stainless steel corrosion-resistant in all environments. Generally, for applications in the ocean, ships, sewage treatment, and acid environments, 316 material is recommended as it has a higher ability to resist intergranular corrosion. Choosing the appropriate stainless steel based on the usage environment and purpose can extend the service life and maintain a shiny appearance.