Stainless steel / UNS S31008
310S is the lower-carbon version of 310 used for plate and sheet, improving weldability and resistance to sensitisation while keeping 310's high-temperature oxidation resistance.
- UNS S31008
- W.Nr. 1.4845
- Spec ASTM A240
- Density 7.9 g/cm³
Also known as / equivalents
| System | Designation |
|---|---|
| UNS | S31008 |
| W.Nr. | 1.4845 |
| EN | X8CrNi25-21 |
| JIS | SUS310S |
| Also known as | AISI 310S, 1.4845, SUS310S |
Chemical composition
| Element | Min % | Max % |
|---|---|---|
| C | — | 0.08 |
| Mn | — | 2.00 |
| P | — | 0.045 |
| S | — | 0.030 |
| Si | — | 1.50 |
| Cr | 24.0 | 26.0 |
| Ni | 19.0 | 22.0 |
| Fe | Bal. | — |
Mechanical properties
| Property | Value |
|---|---|
| Tensile strength (min) | 515 MPa (74.7 ksi) |
| Yield strength, 0.2% offset (min) | 205 MPa (29.7 ksi) |
| Elongation in 50 mm (min) | 40 % |
| Hardness | 217 HB max |
Physical properties
| Property | Metric | Imperial |
|---|---|---|
| Density | 7.9 g/cm³ | 0.285 lb/in³ |
| Magnetic response | Non-magnetic when annealed; may become slightly magnetic after cold work | — |
Available forms & specifications
| Form | Specification | Size range |
|---|---|---|
| Sheets, plates & coils | ASTM A240 / ASME SA240 | 0.3 mm – 6 mm |
| Seamless & welded pipe | ASTM A312 / ASME SA312 | 1/8" – 24" NB |
| Tubes | ASTM A213, A249, A269 | 1/8" – 24" NB |
| Bars & rods | ASTM A276, A479 | 3 mm – 500 mm |
| Flanges & forgings | ASTM A182 / ASME SA182 | 1/2" – 48" NB (larger on request) |
| Buttweld fittings | ASTM A403 / ASME SA403 | 1/2" – 48" NB |
| Fasteners | ASTM A193 / A194, F593 / F594 | M3 – M56 |
Corrosion & temperature resistance
Corrosion resistance rises with chromium, molybdenum and nitrogen: 304 handles general atmospheric and food-contact service, 316/317 add resistance to chlorides and pitting, 904L handles strong reducing acids, and stabilised 321/347 resist intergranular attack after welding or high-temperature exposure.
Applications
SS 310S: Furnace linings, kilns, heat exchangers. Process piping, tanks and vessels, heat exchangers, food, dairy and pharmaceutical equipment, architectural work and general engineering.
SS 310S vs SS 310
| SS 310S | SS 310 | |
|---|---|---|
| UNS | S31008 | S31000 |
| Key property | Heat resisting, lower carbon than 310 | Oxidation resistance to ~1,100 °C |
| Typical use | Furnace linings, kilns, heat exchangers | Furnace parts, burners, heat-treatment fixtures |
| Cr (wt %) | 24.0–26.0 | 24.0–26.0 |
| Ni (wt %) | 19.0–22.0 | 19.0–22.0 |
| Mo (wt %) | — | — |
| C (wt %) | ≤ 0.08 | ≤ 0.25 |
| Tensile / yield (min, MPa) | 515 / 205 | 515 / 205 |
Frequently asked questions
What is the UNS number of SS 310S?
SS 310S is designated UNS S31008 (W.Nr. 1.4845, EN X8CrNi25-21).
What is SS 310S used for?
Heat resisting, lower carbon than 310. Typical uses: furnace linings, kilns, heat exchangers.
Is SS 310S magnetic?
Non-magnetic when annealed; may become slightly magnetic after cold work.
In which forms can I buy SS 310S from Rajkamal Metals?
Coils & Strips, Sheets & Plates, Pipes & Tubes, Round Bars & Rods, Structural Sections, Flanges, Buttweld Fittings, Socket Weld & Threaded Fittings, Fasteners, Ferrule / Instrumentation Fittings, Dairy Fittings, Dish Ends, SS Tanks, Custom Orders. Sizes as per standard; other sizes on request.
Do you supply a Mill Test Certificate with SS 310S?
Yes. Actual values are given in the Mill Test Certificate (EN 10204 3.1) supplied with each order.
What is the difference between SS 310S and SS 310?
SS 310S: heat resisting, lower carbon than 310. SS 310: oxidation resistance to ~1,100 °c. See the comparison table on this page.
Last updated: 30 October 2026. Grade names identify the supply range; designations are not engineering equivalents. Availability, make, origin and documentation are confirmed at quotation.
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