AISI 316 vs 316L Stainless Steel, Difference of SS316 & SS316L Properties Composition Yield Strength Density

Both AISI 316 vs 316L stainless steel are molybdenum (Mo) containing austenitic stainless steel grades. The main difference between 316 and 316L stainless steel is the level of carbon content, weldability, corrosion resistance and mechanical properties. SS316 has a 0.08% max carbon content while SS316L (UNS S31603) only has a maximum 0.03% carbon content.

Since SS 316L has a much lower carbon content than SS316, the welding of 316L stainless steel is better than SS 316. In addition, AISI 316 might lead to stress-corrosion cracking or dimensional instability in service after welding, so postweld heat treatment is required for stress relief to reduce intergranular corrosion or stress-assisted intergranular corrosion, while SS316L generally does not have these problems.

SS316L can be used in applications where annealing cannot be performed after welding and maximum corrosion resistance is required.

AISI 316 (UNS S31600) and 316L (UNS S31603) are US steel grades, SUS 316 and SUS 316L are Japanese stainless steel grades.

Because of the additional molybdenum in this steel, the overall performance of the steel is better than that of AISI 310 and AISI 304 stainless steel. SS316 also has good resistance to chloride attack and is therefore commonly used in the marine environment.

Material 316L meaning: “3” refers to 300 series austenitic chromium-nickel alloys, L is stand for “Low carbon”.

Difference Between SS316 and SS316L Chemical Composition

Difference between 316 and 316L stainless steel composition is summarized in the tables below.

		SS316 and SS316L Chemical Composition (%)
UNS	Grade	C, ≤	Si, ≤	Mn, ≤	P, ≤	S, ≤	Ni	Cr	Mo
UNS S31600	316	0.08	1.00	2.00	0.045	0.030	10.0-14.0	16.0-18.0	2.0-3.0
UNS S31603	316L	0.03	1.00	2.00	0.045	0.030	10.0-14.0	16.0-18.0	2.0-3.0

AISI 316L Stainless Steel Properties

ASTM AISI 316L stainless steel properties are listed in the tables below, including mechanical properties and physical properties.

SS316 vs SS316L Mechanical Properties

The tables below give AISI 316 vs 316L stainless steel mechanical properties such as yield strength, tensile strength, elongation and hardness in different product forms and conditions.

			SS316 vs SS316L Mechanical Properties
ASTM Type	AISI Type	Conditions	Tensile Strength, MPa(ksi), ≥	0.2% Yield Strength, MPa(ksi),≥	Elongation in 50 mm (2 in.), %, ≥	Reduction of Area, %, ≥	Brinell Hardness (HBW), ≤	Rockwell Hardness (HRBW), ≤	Product forms
ASTM A276/A276M	316	Annealed, Hot finished	515 (75)	205 (30)	40	50	–	–	Bars and Shapes
	316L		485 (70)	170 (25)	40	50	–	–
	316	Annealed, Cold finished, Dia.≤12.7 mm (0.5 in.)	620 (90)	310 (45)	30	40	–	–
	316L
	316	Annealed, Cold finished, Dia>12.7 mm (0.5 in.)	515 (75)	205 (30)	30	40	–	–
	316L		485 (70)	170 (25)	30	40	–	–
ASTM A580/A580M	316	Annealed	520 (75)	210 (30)	35	50			Wire
	316L		485 (70)	170 (25)	35	50	–	–
	316	Cold finished	620 (90)	310 (45)	30	40	–	–
	316L
ASTM A240/A240M	316		515 (75)	205 (30)	40	–	217	95	Plate, Sheet, and Strip
	316L		485 (70)	170 (25)	40	–	217	95
ASTM A473/A473M	316	Annealed	515 (75)	205 (30)	40	50	–	–	Forgings
	316L		450 (65)	170 (25)	40	50	–	–

1 MPa = 1 N/mm2

ASTM SAE AISI 316L Physical Properties

The datasheet below gives SS 316L density, melting point and magnetic permeability.

AISI 316L (UNS S31603) Physical Properties
Density, g/cm3 (lb/in.3)	8.03 (0.29)
Melting point, °C (°F)	1375-1400 (2500-2550)
Magnetic permeability	1.02 (Approximate)

316L Heat Treatment

Annealing: The recommended annealing temperatures for 316L wrought steel is 1400 °C (1900 °F).

Stress Relieving: Stress relief is usually not required unless you know or suspect that the environment will cause stress corrosion.

Development Grades

On the basis of 316, many steel types were developed. For example, after adding a small amount of titanium (Ti), SS 316Ti was developed. 316N was developed after adding a small amount of nitrogen (N), SS 317L was developed from the addition of nickel (Ni) and molybdenum (Mo).

Equivalent Grade

AISI 316L SS equivalent to European EN standards (German DIN, British BSI, French NF…), Japanese JIS standards, Chinese GB standards, ISO and more.