SS 310 / 310S — Sheet, Plate, Coil, Pipe & Tube & Fittings
Also sold as AISI 310S · UNS S31008 · W.Nr 1.4845 · Heat-resisting stainless
SS 310 / 310S is a heat-resisting austenitic stainless steel with 25% chromium and 20% nickel, chosen for furnaces, burners and heat treatment at high temperature. We supply it as sheet, plate, coil, pipe & tube, fittings, flanges, fasteners, with EN 10204 3.1 certificates, from Mumbai to India, the Gulf, South-East Asia, South America, Europe, the UK and the USA.
- UNS S31008
- W.Nr 1.4845
- PREN ≈ 25
- ρ 7.9 g/cm³
Reviewed by the Kanak Steel & Engineering Co. technical team · Updated October 2026
SS 310 / 310S Products
SS 310 / 310S Names, Designations & Composition
SS 310 / 310S is one alloy sold under several names. Its UNS number is S31008, the European material number is W.Nr 1.4845 and the EN name is X8CrNi25-21. The chart on the right shows the specified range of each main alloying element; the balance is the base metal.
SS 310 / 310S Specifications by Product — Which Standard Applies?
The material standard changes with the product form. This is the table buyers ask for most.
| Product | Material standard | Dimensions |
|---|---|---|
| SS 310 / 310S sheet | ASTM A240 | ASTM A480 / B906 |
| SS 310 / 310S plate | ASTM A240 | ASTM A480 / B906 / A20 |
| SS 310 / 310S coil | ASTM A240 | ASTM A480 |
| SS 310 / 310S pipe & tube | ASTM A312 TP310S · ASTM A312 · A358 | ASME B36.19 / B36.10 |
| SS 310 / 310S fittings | ASTM A403 WP310S · ASTM A182 F310 | ASME B16.9 · B16.11 |
| SS 310 / 310S flanges | ASTM A182 F310 | ASME B16.5 · B16.47 |
| SS 310 / 310S fasteners | May be machined from ASTM A276 / A479 bar (UNS S31008), where applicable; finished fastener requirements are to the purchase specification or project drawing | ASME B18.2.1 · B18.2.2 |
SS 310 / 310S Chemical Composition
Under technical review for TDS.
| Element | Current requirement |
|---|---|
| Chromium | As specified |
| Nickel | As specified |
| Carbon | As specified |
| Manganese | As specified |
| Silicon | As specified |
| Phosphorus | As specified |
| Sulphur | As specified |
| Iron | As specified |
Numerical specification requirements are published only after the applicable current standard edition has been verified. Governing specification to be verified: ASTM A240 for UNS S31008.
SS 310 / 310S Mechanical Properties
Under technical review for TDS.
| Property | Current requirement |
|---|---|
| Tensile strength | As specified |
| Yield strength 0.2% | As specified |
| Elongation | As specified |
| Hardness | As specified |
Numerical specification requirements are published only after the applicable current standard edition has been verified. Governing specification and condition to be verified: ASTM A240 for UNS S31008 — Annealed plate & sheet.
Density & Physical Properties
| Property | Value |
|---|---|
| Density | 7.9 g/cm³ |
| Melting range | 1400 – 1450 °C |
| Magnetic | Non-magnetic annealed |
| PREN (approx.) | ≈ 25 |
SS 310 / 310S Equivalent Grades
SS 310 / 310S Corrosion Resistance — What Each Element Does
25% chromium builds a tight scale that resists oxidation in continuous service up to about 1100 °C.
20% nickel keeps the alloy austenitic and strong at furnace temperatures.
Silicon improves resistance to scaling and carburising atmospheres.
Without molybdenum, 310S is not a chloride grade — use it for heat, not for seawater.
SS 310 / 310S vs 304, 321 and 800
| Grade | PREN (approx.) | Pick it for |
|---|---|---|
| Incoloy 800 / 800H / 800HT | — | Furnaces, petrochemical heaters and high-temperature piping |
| SS 304 | ≈ 18 | General corrosion resistance, food, water and architectural work |
| SS 321 | ≈ 18 | High-temperature service between 425 and 815 °C |
| SS 310 / 310S | ≈ 25 | Furnaces, burners and heat treatment at high temperature |
Welding SS 310 / 310S
| Matching filler | ER310 (AWS A5.9) |
|---|---|
| Also used | ERNiCr-3 for joints to nickel alloys |
SS 310 / 310S for export
FOB / CIF · Nhava Sheva (JNPT), MumbaiSS 310 / 310S — questions buyers ask
What is SS 310 / 310S?
SS 310 / 310S is a heat-resisting austenitic stainless steel with 25% chromium and 20% nickel. It is chosen for furnaces, burners and heat treatment at high temperature.
Which standards cover SS 310 / 310S products?
Sheet: ASTM A240; Plate: ASTM A240; Coil: ASTM A240; Pipe & Tube: ASTM A312 TP310S · ASTM A312 · A358; Fittings: ASTM A403 WP310S · ASTM A182 F310; Flanges: ASTM A182 F310; Fasteners: May be machined from ASTM A276 / A479 bar (UNS S31008), where applicable; finished fastener requirements are to the purchase specification or project drawing. Always name the standard and edition on your order.
What is the UNS number of SS 310 / 310S?
UNS S31008 (310S) · S31000 (310), with the European material number W.Nr 1.4845.
What is the density of SS 310 / 310S?
7.9 g/cm³ — use it to calculate weights: plate kg = L(m) × W(m) × t(mm) × 7.9.
SS 310 / 310S or Incoloy 800 / 800H / 800HT?
SS 310 / 310S suits furnaces, burners and heat treatment at high temperature; Incoloy 800 / 800H / 800HT is the step up for furnaces, petrochemical heaters and high-temperature piping.
Sources: the ASTM / ASME specifications named on this page and producer datasheets · Last updated October 2026