There is stainless steel grade 304, and then there is grade 316.
The composition of stainless steel grade 304 has 18-20% Chromium (Cr) and 8-12% Nickel (Ni) while the stainless steel 316 has 16-18% Chromium (Cr) and 10-14% Nickel (Ni) as well as 2-3% Molybdenum (Mo).
What’s the real difference? It means stainless steel grade 316 has a higher resistance to pitting and corrosion in non-oxidising acids. This grade is generally known as a marine grade, which means it can be submerged in salt water or exposed to harsh outdoor conditions.
Stainless steel grade 304 is used for general applications including sanitary process lines for food and beverages.