When looking at 304 stainless steel vs 316, it is hard to notice the difference between them. However, when manufacturing with 304 vs 316 stainless steel, the difference can be huge. Keep reading to learn more about the two most popular types of stainless steel.
The high levels of chromium and nickel found in 304 and 316 stainless steel provides them with a strong resistance to heat, abrasion, and corrosion. Not only are they known for their resistance to corrosion, they are also known for their clean appearance and overall cleanliness.
Kloeckner Metals is a full-line stainless steel supplier and service center. Download our stainless steel spec sheet and check what Kloeckner Metals routinely stocks.
Both types of stainless steel appear in wide-ranging industries . As the most common grade of stainless steel, 304 is considered the standard “18/8” stainless. 304 stainless steel is widely used because it is durable and easy to form into various forms such as stainless steel sheet stainless steel bar , and stainless steel tube . 316 steel’s resistance to chemicals and marine environments makes it a popular choice among manufacturers.
The five classes of stainless steel are organized based on their crystalline structure (how their atoms are arranged). Out of the five classes, 304 and 316 stainless steel are in the austenitic grade class. The structure of austenitic grade stainless steels makes them non-magnetic and prevents them from being hardenable by heat treatment.
The medical industry commonly uses 304 SS because it endures the powerful cleaning chemicals without corroding. As one of the few alloys that meets the Food and Drug Administration’s sanitary regulations for food preparation, the food industry often uses 304 SS.
316 contains many similar chemical and mechanical properties as 304 stainless steel. To the naked eye, the two metals look the same. However, the chemical composition of 316, which is made up of 16% chromium, 10% nickel, and 2% molybdenum, is the main difference between 304 and 316 stainless steel.
The addition of Molybdenum in 316 makes it much more corrosion resistant than similar alloys. Due to its superior resistance to corrosion, 316 is one of the staple metals for marine environments. 316 stainless steel is also utilized in hospitals because of its durability and cleanliness.
Fun fact: The Chicago Bean is made from 316 stainless steel!
Heat resistance is an important factor to consider when comparing the different grades of stainless steel. The melting range of 304 is around 50 to 100 degrees Fahrenheit higher than 316. Although the melting range of 304 is higher than 316, they both have good resistance to oxidization in intermittent service up to 870°C (1500℉) and in continuous service at 925°C (1697℉).
What makes 316 more expensive than 304 stainless steel? The increase of nickel content and the addition of molybdenum in 316 makes it more expensive than 304. On average, the price of 316 stainless steel 40% higher than the price of 304 SS.
When comparing 304 stainless steel vs 316, they both have pros and cons to consider when deciding which one to use for different applications. For instance, 316 stainless steel is more resistant than 304 to salt and other corrosives. So, if you are manufacturing a product that will often face exposure to chemicals or a marine environment, 316 is the better choice.
On the other hand, if you are manufacturing a product that does not need strong corrosion resistance, 304 is a practical and economical choice. For many applications, 304 and 316 are actually interchangeable.
Kloeckner Metals is a full-line stainless steel supplier and service center. Kloeckner Metals combines a national footprint with the latest fabrication and processing technologies and most innovative customer service solutions.
The simple answer is 304 contains 18% chromium and 8% nickel while 316 contains 16% chromium, 10% nickel and 2% molybdenum. The molybdenum is added to help resist corrosion to chlorides (like sea water and de-icing salts). I found the brochure Stainless Steel for Coastal and Salt Corrosion Applications to be very helpful as a general reference for using stainless steel in our area.
Click here to view our 304 vs 316 stainless steel infographic!
The last thing you need is your outdoor electrical enclosure rusting out on you.
Not only is there the danger of exposing all your critical electrical components inside, it could cost you a lot to replace when it shorts out. We’re talking parts damage and replacement, repair costs including labor and downtime. I’ve seen some real horror shows when enclosures rust out. It’s not pretty. The good news is we have a simple cost effective solution. We found that by using 316 stainless steel instead of 304 stainless steel on an outdoor enclosure that will be exposed to the elements (like on an oil rig, for example) not only increases the life span of the enclosure but it is much safer to be around.
How do you know you’re getting 316 stainless steel instead of 304 stainless steel?
You can’t tell just by looking at it. There’s no visible difference between two identical pieces of sheet metal, a polished or grained the exact same way. That’s why you need a material test report (MTR) of the actual material to validate it as being 304 or 316. We make sure we get one with every shipment we receive at Nema Enclosures so that we can assure our customers that the enclosure and its parts are constructed of the exact stainless steel material, as specified and ordered. Some small parts such as clamps and mounting feet, constructed of 316 stainless steel are specifically marked, in this case a number 6 within a circle, as shown in the photo above.
What is Type 304 stainless steel and what’s it used for?
Type 304, with its chromium-nickel content and low carbon, is the most versatile and widely used of the austenitic stainless steels. Its alloys are all modifications of the 18% chromium, 8% nickel austenitic alloy. Type 304 proves to be resistant to oxidation, corrosion, and durability. All provide ease of fabrication and cleaning, prevention of product contamination offer a variety of finishes and appearances. Type 304 stainless steels are used in corrosion resistant electrical enclosures, auto molding and trim, wheel covers, kitchen equipment, hose clamps, exhaust manifolds, stainless hardware, storage tanks, pressure vessels and piping.
What is Type 316 stainless steel and what’s it used for?
Type 316 stainless steel is an austenitic chromium-nickel stainless and heat-resisting steel with superior corrosion resistance as compared to other chromium-nickel steels when exposed to many types of chemical corrodents such as sea water, brine solutions, and the like. Since Type 316 stainless steel alloy contains molybdenum bearing it has a greater resistance to chemical attack than 304. Type 316 is durable, easy-to-fabricate, clean, weld and finish. It is considerably more resistant to solutions of sulfuric acid, chlorides, bromides, iodides and fatty acids at high temperature. Stainless steels containing molybdenum are required in the manufacture of certain pharmaceuticals in order to avoid excessive metallic contamination. The bottom line is that Type 316 stainless steel costs a little more upfront but you could save a whole lot on the back end – especially if your enclosure is going to be used outdoors. Something worth keeping in mind when you’re designing your next enclosure. To place an order or if you have questions please contact us today at 713-921-2233.
If you want to learn more, please visit our website Structure of the graphite crystal, Continuous Casting in Graphite Materials, Experimental graphite crucible.