Advantages of 316 Stainless Steel over 304 Stainless Steel

Posted: 5/8/2019

Steel isn’t ever just steel. Because it’s an alloy, different types of metallic compositions can lead to different types of steel. However, the most common type is 304 stainless steel.

Containing approximately 18% to 20% chromium and 8% to 10.5% nickel, 304 stainless steel offers all of the attributes you’d expect. Ease of fabrication. A wide variety of electrical, chemical storage, furnishing, and piping applications (just to name a few).

On paper, 316 stainless steel looks very similar to 304 stainless steel. However, a slight variation in the metals mix leads to very different results. What are they, and how does 316 differ from 304?

Superior Corrosion and Chlorine Resistance

Like 304 stainless steel, 316 contains chromium and nickel. However, it also has molybdenum (2% to 3%) as part of its makeup. That small addition of atomic number 42 lends some unique characteristics to 316 stainless steel.

For one thing, 316 stainless has a stronger resistance to various chemical agents that might damage or corrode 304 stainless steel. It can tolerate fatty acids, sulfuric acid, tartaric acid, and chlorides, even at high temperatures. That makes it ideal for applications in surgical tools, food-related products, and various aspects of pharmaceutical production.

However, 316 stainless steel also excels at resisting brine. That makes it ideal for working in marine applications. Expect to find it in products as diverse as handrails, lamps posts, ladders, various deck components on watercraft, and propeller shafts. Steel with higher levels of molybdenum (up to 6%) appear in oil-platform components.

Longer Life Expectancy Across a Variety of Applications

When temperatures get higher, 316 stainless steel gets tougher. Though it remains just as easy to fabricate as 304 stainless steel, it will not harden under heat treatment. If your application requires annealing, know that you will need to first heat it between 1,900 and 2,100 degrees Fahrenheit prior to quenching.

This incipient toughness means that 316 functions well when used in applications such as jet engines, furnaces, various kinds of manifolds, and (naturally) pump parts.

There’s one quirk of 316 stainless steel to be aware of: Though it’s naturally non-magnetic, it can become magnetic when cold worked.

Can March Pump Help Me Find the Best Steel for my Application?

Selecting from types of steel can seem a bit bewildering. Fortunately, March Pumps has been working with steel since 1954. We understand the ins and outs of all sorts of metals — and we particularly know how they work with pumps. We’re happy to answer any and every question about your application. Reach out to us via phone at (847) 725-0580 or through our contact page.

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