Science, Tech, Math › Science Type 316 and 316L Stainless Steels Compare the two types of stainless steel Share Flipboard Email Print ThoughtCo / James Bascara Science Chemistry Chemistry In Everyday Life Basics Chemical Laws Molecules Periodic Table Projects & Experiments Scientific Method Biochemistry Physical Chemistry Medical Chemistry Famous Chemists Activities for Kids Abbreviations & Acronyms Biology Physics Geology Astronomy Weather & Climate By Terence Bell University of British Columbia Carleton University Terence Bell wrote about commodities investing for The Balance, and has over 10 years experience in the rare earth and minor metal industries. our editorial process Twitter Twitter LinkedIn LinkedIn Terence Bell Updated March 02, 2020 Alloys often are added to steel to increase desired properties. Marine-grade stainless steel, called type 316, is resistant to certain types of corrosive environments. There is a variety of different types of 316 stainless steel. Some common types are the L, F, N, and H variants. Each is slightly different, and each is used for different purposes. The "L" designation means 316L steel has less carbon than 316. Qualities Shared By 316 and 316L While similar to Type 304, which is common in the food industry, both type 316 and 316L exhibit better corrosion resistance and are stronger at elevated temperatures. They also are both non-hardenable by heat treatment and can be readily formed and drawn (pulled or pushed through a die or smaller hole). Annealing (a treatment to reduce hardness and increase ductility, or the ability to accept plastic deformation) 316 and 316L stainless steels require heat treatment of between 1,900 and 2,100 degrees Fahrenheit (1,038 to 1,149 degrees Celsius) before rapidly quenching. Differences Between 316 and 316L 316 stainless steel has more carbon in it than 316L. This is easy to remember, as the L stands for "low." But even though it has less carbon, 316L is very similar to 316 in almost every way. Cost is very similar, and both are durable, corrosion-resistant, and a good choice for high-stress situations. 316L, however, is a better choice for a project that requires a lot of welding because 316 is more susceptible to weld decay than 316L (corrosion within the weld). However, 316 can be annealed to resist weld decay. 316L also is a great stainless steel for high-temperature, high-corrosion uses, which is why it's so popular for use in construction and marine projects. Neither 316 nor 316L is the cheapest option. 304 and 304L are similar but lower-priced. And neither are as durable as 317 and 317L, which have higher molybdenum content and are better for overall corrosion resistance. Qualities of Type 316 Steel Type 316 steel is an austenitic chromium-nickel stainless steel that contains between two and 3% molybdenum. The molybdenum content increases corrosion resistance, improves resistance to pitting in chloride ion solutions, and increases strength at high temperatures. Type 316 grade stainless steel is particularly effective in acidic environments. This grade of steel is effective in protecting against corrosion caused by sulfuric, hydrochloric, acetic, formic, and tartaric acids, as well as acid sulfates and alkaline chlorides. How Type 316 Steel Is Used Common uses for type 316 stainless steel include in the construction of exhaust manifolds, furnace parts, heat exchangers, jet engine parts, pharmaceutical and photographic equipment, valve and pump parts, chemical processing equipment, tanks, and evaporators. It also is used in pulp, paper, and textile processing equipment and for any parts exposed to marine environments. Qualities of Type 316L Steel The lower carbon content in 316L minimizes deleterious carbide precipitation (carbon is drawn out of the metal and reacts with chromium due to heat, weakening the corrosion resistance) as a result of welding. Consequently, 316L is used when welding is required to ensure maximum corrosion resistance. Properties and Composition of 316 and 316L Steels Physical Properties of type 316 and 316L steels: Density: 0.799g/cubic centimeterElectrical resistivity: 74 microhm-centimeters (20 degrees Celsius)Specific Heat: 0.50 kiloJoules/kilogram-Kelvin (0–100 degrees Celsius)Thermal conductivity: 16.2 Watts/meter-Kelvin (100 degrees Celsius)Modulus of Elasticity (MPa): 193 x 103 in tensionMelting Range: 2,500–2,550 degrees Fahrenheit (1,371–1,399 degrees Celsius) Here is a breakdown of the percentages of various elements used to create type 316 and 316L steels: Element Type 316 (%) Type 316L (%) Carbon 0.08 max. 0.03 max. Manganese 2.00 max. 2.00 max. Phosphorus 0.045 max. 0.045 max. Sulfur 0.03 max. 0.03 max. Silicon 0.75 max. 0.75 max. Chromium 16.00-18.00 16.00-18.00 Nickel 10.00-14.00 10.00-14.00 Molybdenum 2.00-3.00 2.00-3.00 Nitrogen 0.10 max. 0.10 max. Iron Balance Balance Properties and Composition of Type 201 Stainless Steel Type 304 and 304L Stainless Steel Ferritic Stainless Steel Compare 20 Grades of Knife Steel The Modern Steel Manufacturing Process Why Is Stainless Steel Stainless? The Characteristics of Austenitic Stainless Steel How and Why Steel Is Normalized Steel Grades and Properties Top Steel Alloying Agents Metal Profile: Steel The 200 Series of Stainless Steels What You Should Know About Metallurgical Coal The Metal Profile for Molybdenum What Happens When Metals Undergo Heat Treatment? What Are the Types and Properties of Steel?