Glossary

316 stainless steel is an austenitic grade of stainless steel known for its superior corrosion resistance compared to the more common 304 (18/8) stainless. Like other austenitic steels, it contains chromium and nickel, but what sets it apart is the addition of molybdenum (about 2–3%), which significantly improves its resistance to pitting, crevice corrosion, and attack from chlorides and saltwater environments.

The typical composition of 316 stainless steel is around 16–18% chromium, 10–14% nickel, 2–3% molybdenum, and the balance iron, with small amounts of manganese, silicon, and carbon. This combination makes it exceptionally durable in marine conditions, chemical processing environments, and medical applications.

Because of its toughness and resistance to harsh conditions, 316 stainless steel is often called “marine grade stainless steel.” It’s widely used in shipbuilding, coastal architectural structures, food and pharmaceutical processing equipment, surgical instruments, and high-strength fasteners that must withstand exposure to moisture, chemicals, or salt.

In fastener applications, 316 stainless steel bolts, nuts, and washers are preferred when maximum corrosion resistance is needed—such as in marine, chemical, or outdoor structural settings. While it is more expensive than 304 stainless, the added longevity and reliability in severe environments often justify the cost.