UNS S31600, commonly known as Grade 316, is the second most widely used austenitic stainless steel after 304. The addition of molybdenum gives 316 significantly improved corrosion resistance, especially against chlorides and marine environments, making it the material of choice for chemical processing, marine, pharmaceutical, and food-industry applications. The low-carbon variant, 316L/UNS S31603, further reduces the risk of sensitization during welding.
This article provides accurate, standard-compliant chemical composition, mechanical properties, and physical properties of UNS S31600 / 316 and 316L based on ASTM, ASME, EN, and other international specifications.
UNS S31600 Chemical Composition
|
Element |
316 (UNS S31600) % |
316L (UNS S31603) % |
316 (EN 1.4401) % |
316L (EN 1.4404) % |
|
Carbon (C) |
≤ 0.080 |
≤ 0.030 |
≤ 0.07 |
≤ 0.030 |
|
Silicon (Si) |
≤ 1.00 |
≤ 1.00 |
≤ 1.00 |
≤ 1.00 |
|
Manganese (Mn) |
≤ 2.00 |
≤ 2.00 |
≤ 2.00 |
≤ 2.00 |
|
Phosphorus (P) |
≤ 0.045 |
≤ 0.045 |
≤ 0.045 |
≤ 0.045 |
|
Sulfur (S) |
≤ 0.030 |
≤ 0.030 |
≤ 0.015 |
≤ 0.015 |
|
Chromium (Cr) |
16.0 – 18.0 |
16.0 – 18.0 |
16.5 – 18.5 |
16.5 – 18.5 |
|
Nickel (Ni) |
10.0 – 14.0 |
10.0 – 14.0 |
10.0 – 13.0 |
10.0 – 13.0 |
|
Molybdenum (Mo) |
2.00 – 3.00 |
2.00 – 3.00 |
2.00 – 2.50 |
2.00 – 2.50 |
|
Nitrogen (N) |
≤ 0.10 |
≤ 0.10 |
≤ 0.10 |
≤ 0.10 |
|
Iron (Fe) |
Balance |
Balance |
Balance |
Balance |
UNS S31600 Mechanical Properties
|
Property |
316 / 316L (ASTM A240, A666) |
Unit |
EN 1.4401 / 1.4404 (Solution Annealed) |
|
Tensile Strength (min) |
515 MPa (75 ksi) |
MPa / ksi |
≥ 520 MPa |
|
Yield Strength 0.2% offset (min) |
205 MPa (30 ksi) |
MPa / ksi |
≥ 220 MPa |
|
Elongation in 50 mm (min) |
40% |
% |
≥ 45% |
|
Hardness (Brinell, max) |
217 HB |
HB |
≤ 215 HB |
|
Hardness (Rockwell B, max) |
95 HRB |
HRB |
– |
|
Modulus of Elasticity |
193 GPa (28 × 10⁶ psi) |
GPa |
200 GPa |
|
Poisson's Ratio |
0.27 – 0.30 |
– |
0.28 – 0.30 |
Note: 316L has nearly identical strength to 316 but offers better weldability due to lower carbon.
UNS S31600 Physical Properties
|
Property |
Value (316 / 316L) |
Unit |
|
Density |
8.00 g/cm³ (0.289 lb/in³) |
g/cm³ |
|
Specific Heat Capacity |
500 J/kg·K (0.12 Btu/lb·°F) |
J/kg·K |
|
Thermal Conductivity (100 °C) |
16.3 W/m·K (112 Btu·in/ft²·h·°F) |
W/m·K |
|
Thermal Expansion (0–100 °C) |
16.0 × 10⁻⁶ /°C (8.9 × 10⁻⁶ /°F) |
/°C |
|
Electrical Resistivity |
0.74 μΩ·m |
μΩ·m |
|
Magnetic Permeability (annealed) |
1.02 – 1.008 (essentially non-magnetic) |
– |
|
Melting Range |
1375 – 1400 °C (2500 – 2550 °F) |
°C |
Why Choose UNS S31600?
For heavy gauge welding or extreme corrosive environments, the lower carbon variant, 316L, is often preferred to mitigate sensitization.
High-Temperature Strength: It maintains good strength and corrosion resistance at elevated temperatures, suitable for boiler components and furnace parts.
