Would 304 or 316 stainless work better for my project? What are the differences and when should I prefer one over the other? If these are the questions you are asking yourself, look no further!
Both of these grades fall under the Austenitic Family of stainless steel, which means they are adaptable to cold forming, easy to weld, and offer high corrosion resistance. However, their difference in chemical makeup allows 316 to have a higher corrosion resistance, giving it the name “marine grade.” Below we will dive into a brief description, pros & cons, and when you should use each.
304 stainless, also known as A2 stainless, is the most common grade of the Austenitic Family. It contains a high amount of nickel (8-10.5%) and chromium (18-20%). The other major alloying elements are manganese, silicon, and carbon. The remainder is predominantly iron.
304 stainless is a more affordable and machinable product than 316 stainless. 304 is often seen in household and industrial applications like sinks, refrigerators, fasteners, pipes, heat exchangers, and structures in environments where carbon steels would rust.
316 stainless, also known as A4 stainless, is defined by its stellar corrosion resistance. It is chemically similar to 304, with high levels of chromium and nickel. Also, 316 has silicon, manganese, and carbon, with iron as the remainder. However, 316 has a significant amount of molybdenum (2-3%), which 304 lacks.
This molybdenum gives 316 superb abilities in salt-water and marine applications. Hence why 316 is called “marine” grade. 316 stainless is widely used in chemical process and high-salinity environments. For these reasons it is also often used for chemical processing and storage equipment, medical and surgical devices, and refinery equipment in addition to marine equipment.
Low cost is more important than corrosion resistance
High corrosion resistance is more important than cost
The part requires more forming or machining operations
You are in a marine or corrosive environment
The environment isn’t particularly corrosive
Your application requires higher strength and hardness
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Now that you’ve got more information about 304 vs 316 stainless steel, do you have more questions? Looking to weld your Stainless? Whether your project uses 304 vs 316, or a different grade, check out our blog post about welding the different types of stainless steel.