304L and 315L Stainless SteelIf you’re looking for a high-quality, corrosion-resistant metal for your next project, stainless steel is a great option. But with so many different grades and types of stainless steel available on the market, it can be tough to know which one is right for you. One designation you might come across is “L.” So what does L mean in stainless steel? Keep reading to find out.

The letter L following the grade number, such as 304L, indicates that carbon content is limited to 0.03 percent (normal levels are 0.08 percent maximum and in some grades can be up to 0.15 percent maximum). This lower level of carbon is generally employed where welding will take place because it helps to prevent the chromium from being depleted (by forming chrome carbides at the weld site) and allows it to stay above 10.5 percent. This forms the passive oxide layer that gives stainless its corrosion resistance.

Rolled Metal Products stocks two stainless steel “L” grades – 304L and 316L.


Type 304L stainless steel is a low-carbon version of regular 304, and while it has some different properties than 304, it is still one of the most commonly specified stainless steel used throughout the world due to its corrosion resistance and fabrication versatility.

Other advantages of 304L include:

  • High corrosion resistance, particularly in an oxidizing environment
  • During the welding process, carbon precipitation is eliminated
  • Resistance to moderately aggressive organic acids
  • Except in high-stress situations, weld annealing is not required
  • High heat tolerance
  • After hot forming, it may be air-cooled without cracking
  • After cold forming, it hardens rapidly

Type 316L

Type 316L, the low carbon version of 316 stainless steel, is the second most common austenitic stainless steel after 304 stainless steel. The addition of molybdenum in its chemical composition provides greater corrosion resistance than 304, with respect to localized corrosive attack by chlorides and to general corrosion by reducing acids, such as sulfuric acid. When cold worked, 316 can produce high yield and tensile strengths comparable to Duplex stainless grades.

316L is commonly found in the chemical and petrochemical sectors, as well as food processing, pharmaceutical, medical devices, wastewater treatment, maritime applications, and urban development.

What stainless steel type do you require?

Choosing the right stainless steel grade for your applications can be a crucial decision depending on your specific requirements. Our experts are available to assist you with any stainless steel questions you may have. For more information about our 304L, 316L, or any other stainless steel grades you may be looking for, contact a Rolled Metal Products representative today!