What's the difference between 316 vs 316L stainless steel? The answer is surprisingly simple.
It's the carbon content. 316 stainless steel has a max carbon content of 0.08%. 316L stainless has a max carbon content of 0.03%.
How do you remember which is which? 316L has a Low carbon content. Easy peasy.
Note these are the same materials as SS316 and SS316L, as well as AISI 316 and 316L. No matter how you slice it, the "L" is the difference.
Why Does the Choice Between 316 Vs 316L Stainless Matter?
316 Vs 316L Stainless Steel Corrosion Resistance
Performance-wise, 316L is better than any other stainless steel for very high temperature, high corrosion applications. 316L is easy to fabricate, and is used often in construction, marine, and infrastructure industries due to its durability.
The low carbon content of 316L stainless steel means it's slightly more weldable than grade 316. With a higher carbon content, 316 is more likely to experience weld decay. In other words, 316L is more resistant to intergranular corrosion. However, this is only an issue if the metal needs to be welded over a period of several minutes or it's heated to temperatures between 425-815º C.
316 Vs 316L Cost
If you're choosing materials based on price, the lower carbon content of 316L doesn't make a big difference. They cost approximately the same, with minor price fluctuations due to regular market shifts.
316 vs. 316L in Practical Applications
If you're not sure which type of steel is best for your project, here's the biggest thing to remember: if your project requires lots of welding, 316L is a better choice off the bat. However, 316 can be annealed to resist weld decay if you're set on this grade.
Need both welding AND forming fabrications? Talk to your manufacturer about which material is best for your project.
Overall, both steels are highly durable, corrosion resistant, and perform well under high stress conditions. If you're looking for a cheaper material, 304 and 304L are physically similar to the 316s (slightly less durable) but cost a little less. If you're looking for highest durability, 317 and 317L have a higher molybdenum content, which increases their overall corrosion resistance.
The entire 300 series of austenitic stainless steels are well-known for their strength and long lifespans.
(Editor's note: This article was originally posted in July 2016 and was recently updated.)