Stainless 316 · UNS S31600 · W. Nr. 1.4401
Stainless 316 (S31600): composition, properties, fittings and flanges
Stainless 316 (S31600, W. Nr. 1.4401) is Molybdenum-bearing austenitic stainless steel. Stainless 316 is specified at Chromium 16.0 - 18.0, Nickel 10.0 - 14.0, Molybdenum 2.00 - 3.00. 316 adds 2 - 3 % molybdenum to the 304 base, which roughly doubles resistance to chloride pitting and crevice attack and makes it the minimum…
- UNS
- S31600
- W. Nr.
- 1.4401
- Density
- 8.00 g/cm³ (0.289 lb/in³)
- Key strength
- 515 MPa / 75 ksi
Identification and standards
| Short form | Stainless 316 · UNS S31600 · W. Nr. 1.4401 |
|---|---|
| Classification | Molybdenum-bearing austenitic stainless steel |
| UNS | S31600 |
| Werkstoff number | 1.4401 |
| Material family | Stainless Steel |
Chemical composition
| Element | Composition (wt %) | Why it is there |
|---|---|---|
| Chromium (Cr) | 16.0 - 18.0 | Passive film |
| Nickel (Ni) | 10.0 - 14.0 | Austenite stability |
| Molybdenum (Mo) | 2.00 - 3.00 | Pitting and crevice resistance |
| Carbon (C) | 0.08 max | - |
| Manganese (Mn) | 2.00 max | - |
| Silicon (Si) | 0.75 max | - |
| Phosphorus (P) | 0.045 max | - |
| Iron (Fe) | Balance | Matrix |
Note Single figures are maximum limits unless shown as a range. Always confirm against the heat-specific EN 10204 3.1 certificate supplied with your order.
Mechanical properties
| Tensile strength, min (annealed) | 515 MPa / 75 ksi |
|---|---|
| 0.2 % yield strength, min | 205 MPa / 30 ksi |
| Elongation in 2 in, min | 40 % |
| Typical hardness, annealed | 145 - 190 HB |
| PREN, typical | About 25 |
Warning Values depend on product form, section thickness and heat treatment. Larger sections generally achieve lower strength than thin product; always design against the applicable code allowable stress rather than these figures.
Physical properties
| Density | 8.00 g/cm³ (0.289 lb/in³) |
|---|---|
| Melting range | 1375 - 1400 °C (2500 - 2550 °F) |
| Modulus of elasticity | 193 GPa (28.0 x 10⁶ psi) |
| Thermal conductivity at 20 °C | 16.3 W/m·K |
| Mean coefficient of thermal expansion, 20-100 °C | 16.5 µm/m·°C |
| Specific heat capacity | 500 J/kg·K |
Specifications by product form
| Forgings & flanges | ASTM A182 F316 · ASME SA-182 |
|---|---|
| Butt weld fittings | ASTM A403 WP316 · ASME SA-403 |
| Seamless pipe & tube | ASTM A312 TP316 · ASME SA-312 |
| Plate / sheet / strip | ASTM A240 316 · ASME SA-240 |
| Bar / rod | ASTM A276 / A479 |
| Welding consumables | ER316 |
| UNS / EN / China | UNS S31600 · W. Nr. 1.4401 · GB 06Cr17Ni12Mo2 |
Product forms available
Hangbo supplies this grade in the following forms. Sizes outside the listed range can often be produced to order.
- Forged flanges blanks and finished flanges to ASME B16.5, B16.47 Series A/B and B16.36
- Butt weld elbows, tees, reducers, caps and stub ends to ASME B16.9 and MSS SP-43
- Seamless pipe and tube to the applicable ASTM / ASME pipe specification
- Forged rings, discs and hubs machined to your drawing
Typical applications
- Chemical, petrochemical and pharmaceutical process piping
- Marine hardware, boat fittings and coastal architectural work
- Food, beverage and pharmaceutical clean piping
- Pulp and paper bleach plant equipment
Welding, forming and machining
- Welding
- Weld with ER316 or, better, ER316L filler for low-carbon service. Watch heat input on thick sections to avoid sigma phase during prolonged exposure above 600 °C.
- Heat treatment
- Solution anneal at 1010 - 1120 °C and water quench.
- Hot and cold forming
- Hot work in the range stated by the mill for this grade, then re-solution or re-age before final machining so that the delivered condition matches the certificate.
- Machining
- Machine with sharp carbide or high-speed steel tooling, positive rake, constant feed and ample coolant. Never dwell - the surface work-hardens quickly.
Buy Stainless 316 from Hangbo
Material is supplied with full heat-number traceability, solution annealing or ageing performed under calibrated furnace control, and an EN 10204 3.1 certificate covering chemical analysis, mechanical properties, heat treatment records and the agreed NDT scope. Positive material identification and third party inspection and test reports from SGS are available for critical service.