AISI 316 vs 316L Stainless Steel (UNS S31603)

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.

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

SS316 Vs 316L Stainless Steel

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.

AISI 316L equivalent grade
US European Union ISO Japan China Australia India Rusia Korea
Standards Type Standards Grade (Steel Number) Standard Grade (ISO Number) Standard Grade Standards Grade Standard Grade Standard Grade Standard Grade Standard Grade
AISI SAE;
ASTM
316L
(UNS S31603)
EN 10088-1; EN 10088-2; EN 10088-3 X2CrNiMo17-12-2 (1.4404) ISO 15510 X5CrNiMo17-12-2 (4404-316-03-I) JIS G4303 SUS316L GB/T 20878;
GB/T 1220;
GB/T 3280
00Cr17Ni14Mo2;
022Cr17Ni12Mo2 (New name)
Forging
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