Differences Between 304 and 316 Stainless Steel

Stainless steel is a widely used material known for its resistance to corrosion, durability, and versatile applications. Two of the most popular grades of stainless steel are 304 and 316 stainless steel. Both are austenitic steels, which means they contain a high level of chromium and nickel, providing excellent corrosion resistance. However, there are significant differences between 304 vs 316 stainless steel in terms of their composition, corrosion resistance, and suitable applications.

Composition and Alloying Elements

304 stainless steel is an alloy that contains around 18% chromium and 8% nickel, giving it the nickname “18/8 stainless steel.” These two elements are what give 304 its excellent corrosion resistance and durability. In addition to chromium and nickel, 304 stainless steel also contains trace amounts of carbon, manganese, and silicon.

On the other hand, 316 stainless steel contains about 16% chromium, 10% nickel, and an important addition of 2-3% molybdenum. Molybdenum is the key alloying element that makes 316 stainless steel more resistant to chlorides, acids, and other harsh environments compared to 304.

Key Takeaways of 304 and316 Stainless Steel

304 contains 18% chromium and 8% nickel.
316 contains 16% chromium, 10% nickel, and 2-3% molybdenum.
Molybdenum in 316 increases its resistance to corrosive environments.

Corrosion Resistance

Corrosion resistance is one of the most important factors to consider when selecting stainless steel for an application. Both 316 and 304 stainless steel offer excellent protection against corrosion, but 316 stainless steel is better equipped to handle harsh environments.

304 Stainless Steel: While 304 stainless steel has good corrosion resistance, it may not perform as well as 316 in more corrosive environments, such as in coastal areas or places with high exposure to chloride (like saltwater). It is, however, more than adequate for most everyday applications, such as kitchen appliances, food processing equipment, and general construction.
316 Stainless Steel: The addition of molybdenum makes 316 stainless steel much more resistant to corrosion from chlorides and acidic environments. This is why 316 is often referred to as “marine-grade stainless steel,” as it performs well in saltwater and other aggressive environments. It is commonly used in chemical processing, medical devices, and marine applications.