What are 304 and 316 stainless steel?

The key difference between 304 vs 316 stainless steel that makes them different is the addition of molybdenum, an alloy that drastically enhances corrosion resistance, especially for more saline or chloride-exposed environments. 316 stainless steel contains molybdenum, but 304 does not.

304 Stainless Steel

Grade 304 is the most common austenitic stainless steel. It contains 8 percent nickel and 18% chromium. The alloy also includes other elements – carbon, manganese, and silicon – and the remaining composition is primarily iron. The 304 stainless steel is highly resistant to corrosion and has high nickel-chromium levels.

316 Stainless Steel

316 stainless steel is composed primarily of iron and contains 10% nickel and 16% chromium, as well as small amounts of carbon, manganese, molybdenum, and silicon. Therefore, it is more resistant to corrosion than 304. For this reason, 316 stainless steel is often the preferred choice in marine construction.

How are 304 and 316 stainless steel classified?

Although there are more than 100 grades of stainless steel, most fall into five main categories within the stainless steel family: austenitic, ferritic, martensitic, duplex, and precipitation hardening. These five types of stainless steel are arranged according to their crystal structure. Austenitic grades include 316 and 304 stainless steel sheets. The austenitic system of stainless steel grades makes them non-magnetic and unavailable for heat treatment.

What is the difference between 304 and 316 stainless steel?

316 contains many chemical properties similar to those of 304 stainless steel. To the naked eye, the two metals appear to be identical. The simple answer to this question is that 304 has 18% chromium. 316 has 10% nickel. 2% molybdenum. 316 has added molybdenum to help resist corrosion from some oxides such as seawater or salt water. Next, we briefly describe the characteristics of each of 304 and 316.