Stainless 310S · UNS S31008 · W. Nr. 1.4845
Stainless 310S (S31008): composition, properties, fittings and flanges
Stainless 310S (S31008, W. Nr. 1.4845) is High-chromium high-nickel heat-resistant austenitic stainless steel. Stainless 310S is specified at Chromium 24.0 - 26.0, Nickel 19.0 - 22.0. 310S is the top of the heat-resistant stainless range: 25 % chromium and 20 % nickel hold a protective scale in air to about 1150 °C, well past…
- UNS
- S31008
- W. Nr.
- 1.4845
- Density
- 8.00 g/cm³ (0.289 lb/in³)
- Key strength
- 515 MPa / 75 ksi
Identification and standards
| Short form | Stainless 310S · UNS S31008 · W. Nr. 1.4845 |
|---|---|
| Classification | High-chromium high-nickel heat-resistant austenitic stainless steel |
| UNS | S31008 |
| Werkstoff number | 1.4845 |
| Material family | Stainless Steel |
Chemical composition
| Element | Composition (wt %) | Why it is there |
|---|---|---|
| Chromium (Cr) | 24.0 - 26.0 | Oxidation and scaling resistance |
| Nickel (Ni) | 19.0 - 22.0 | Austenite stability and thermal fatigue |
| Carbon (C) | 0.08 max | - |
| Manganese (Mn) | 2.00 max | - |
| Silicon (Si) | 1.50 max | Scale adherence |
| Phosphorus (P) | 0.045 max | - |
| Sulphur (S) | 0.030 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 |
| Useful continuous service temperature in air | About 1150 °C |
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 | 1400 - 1455 °C (2550 - 2650 °F) |
| Modulus of elasticity | 200 GPa (29.0 x 10⁶ psi) |
| Thermal conductivity at 20 °C | 14.2 W/m·K |
| Mean coefficient of thermal expansion, 20-100 °C | 15.4 µm/m·°C |
| Specific heat capacity | 500 J/kg·K |
Specifications by product form
| Forgings & flanges | ASTM A182 F310S family · ASME SA-182 |
|---|---|
| Butt weld fittings | ASTM A403 WP310S · ASME SA-403 |
| Seamless pipe & tube | ASTM A312 TP310S · ASME SA-312 |
| Plate / sheet / strip | ASTM A240 310S · ASME SA-240 |
| Bar / rod | ASTM A276 / A479 |
| Welding consumables | ER310 |
| UNS / EN / China | UNS S31008 · W. Nr. 1.4845 · GB 06Cr25Ni20 |
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
- Furnace muffles, retorts, annealing covers and radiant tubes
- Cement, lime and mineral kiln internals
- Glass and ceramic furnace hardware
- Thermal oxidiser and incinerator chambers
Welding, forming and machining
- Welding
- Weld with ER310 filler. Sigma phase forms between 650 and 870 °C, so avoid long holds in that range and re-anneal fabrications that have been soaked there.
- Heat treatment
- Solution anneal at 1040 - 1150 °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 310S 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.