316 vs. 304 Grade Stainless Steel: Similarities and Differences

Written By Rachel Novak

Stainless steel hardware comes in a variety of grades and finishes. These different classifications of steel are used to meet differing environmental and physical demands. When selecting stainless steel hardware, it is important to understand the differences between the variety of grades and finishes available so you can choose the products that will work most safely and effectively for your purposes.

Metal hardware products are often composed of either 304 grade or 316 grade stainless steel. It’s difficult to distinguish between these two types of steel visually, but significant differences between the two steel types do exist and are important to understand. Below is a basic guide to the similarities and differences of 304 grade and 316 grade stainless steel.

1.    Composition
The first key difference between 304 grade stainless steel and 316 grade stainless steel relates to composition. Steels are classified in part based on chromium and alloy content and crystalline structure. Austenitic steel – also known as 300 series steel – contains 18% chromium and 8% nickel. This type of steel is incredibly common; about 70% of stainless steel products are composed of austenitic steel. 304 grade stainless steel is considered to be austenitic, while 316 grade stainless steel is considered to be superaustenitic – meaning it contains a higher content of molybdenum, nitrogen and nickel, making it more resistant to corrosion and stress.

2.    Resistance to Corrosion
While both 304 and 316 grade stainless steels are resistant to corrosion, 316 grade stainless steel provides a higher degree of corrosion resistance than 304 grade steel because it includes molybdenum in its composition. As a result, 316 grade stainless steel is better suited for resisting extreme environmental conditions like salt water, de-icing salts, brine solutions and exposure to chemicals. Though 304 grade stainless steel will resist corrosion for a time, it will eventually begin to tarnish.

3.    Uses
Stainless steel type 304 is used frequently in a variety of contexts. It is often found in household products and appliances, including pots and pans, coffee urns, stoves, refrigerators and sinks. It is also commonly used in dairy equipment and the brewing and food producing industries. 304 grade stainless steel is also used frequently for nuts, bolts, screws and other fasteners.

Stainless steel type 316 is more commonly used in severe environments and for industrial processes that require higher levels of resistance to corrosion than 304 grade stainless steel can offer. This type of metal is often used in chemical processing equipment, to create fasteners and hardware used for industrial purposes, and in surgical implants. It is also frequently used in marine environments because of its higher resistance to tarnish and corrosion.

4.    Cost
Typically, 316 grade stainless steel costs slightly more than 304 grade steel because of its enhanced chemical and production properties. The extra cost can be justified, however, because hardware made of type 316 stainless steel is extra resistant to tarnish and corrosion, enabling it to last a very long time.

Henssgen Hardware provides high quality, durable hardware products to consumers, distributors and manufacturers. Our products, which include snap hooks, pulleys, rings and chains, are made of high quality materials. Steel products distributed by Henssgen Hardware are manufactured with 316 grade stainless steel to provide enhanced durability and corrosion resistance.

To learn more about our stainless steel hardware and the variety of other products supplied by Henssgen Hardware, please visit our website, call us at 1-800-833-9598 or contact us via email at [email protected].