What is 316 Stainless Steel & Difference Between 316 and 316L Stainless Steel | CNCLATHING

2020.6.15

As a popular stainless steel grade, 316 stainless steel has many variants like L, H, F, and N, which come in subtle differences. Here we’ll talk about a common type 316L, what’s the difference between 316 and 316L stainless steel, plus alloy 316 definition, composition, properties, and applications.

What is 316 Stainless Steel?

Stainless steel 316, also known as UNS S31600, is mainly composed of Fe, 16-18.5% Cr, 10-14% Ni and 2-3% Mo, also contains <0.03% C, <2% Mn, <1% Si, <0.045% P, and <0.03% S, so it expressed as 0Cr17Ni12Mo2. Check our international standards conversion table for different representation methods for various metals. Grade 316 is a popular austenitic stainless steel alloy and the second most widely used grade after stainless steel 304. Due to the addition of Mo, its corrosion resistance, resistance to acids, alkalis, and chloride pitting are particularly good. 316 stainless can withstand high temperature up to 1200-1300℃, and used in harsh conditions with excellent work hardening performance(non-magnetic) and high temperature strength. When treated with cold-roll, it shows good gloss and beautiful appearance. 

 

CNCLATHING.COM is specialized in 316 stainless steel CNC machining and provides milling/turning/drilling services and precision machined components for various stainless types. 

316 Stainless Steel Properties (Physical and Mechanical)

– Melting point: 2,500℉–2,550℉(1,371℃ –1,399℃)

– Density: 7.98 g/cm3

– Tensile strength (min): 515 MPa 

– Yield strength (0.2% proof, min): 205 MPa

– Elastic Modulus: 193 GPa

– High strength 

– Corrosion resistance

– Resistance to pitting and crevice corrosion in chloride environments

– Excellent forming and welding characteristics

– Readily roll formed

– Susceptible to stress corrosion cracking above 60°C

Applications of 316 Stainless Steel

Due to its excellent corrosion resistance in atmospheric environments and more resistant to corrosive media than 304, alloy 316 is often used to produce equipment and parts used in seawater (boat fittings), chemical industry (laboratory benches, containers), dye, paper making, production machinery of oxalic acid and fertilizer. It is usually regarded as the standard “marine grade stainless steel”, but it is not resistant to warm seawater. In addition, photography devices, food preparation equipment, coastal facilities (coastal architectural paneling, railings & trim), woven or welded screens for mining, quarrying & water filtration, ropes, CD rods, springs, bolts, nuts outdoor electrical enclosures, medical and pharmaceutical equipment are possible stainless steel 316 applications.

Difference Between 316 and 316L Stainless Steel

Even though 316 and 316L have high similarity, their prices are approximately the same, we can also differentiate them in the composition, mechanical properties, and other aspects.

1. Composition

The key difference between standard 316 stainless steel and SS316L is the composition, 316 contains more molybdenum than 316L, which results in increased resistance to pitting and crevice corrosion and better protection when exposed to high-chloride chemicals and acids. In addition, 316L is the low-carbon variation of 316 because it has a lower carbon content than 316, in contrast, grade 316H is the higher carbon version. Type 316 stainless steel contains up to 0.08% carbon while the maximum carbon content of type 316L is 0.03%. The 316L will also be softer than 316 due to the lower carbon. For the percentages of other elements, 316 and 316 have almost no difference.

2. Mechanical Properties

Compare stainless steel 316 and 316L in mechanical properties, including yield strength, tensile strength, elongation, and hardness as below. 

3. Application

316L is a better choice for the application or the fabrication process needs a lot of welding because the lower carbon content minimizes deleterious carbide precipitation. But 316 can be annealed to resist weld decay. And, 316L is the main choice for medical implants, rather than SS316.