SS 310S is an austenitic stainless steel with 24.0–26.0% chromium and 19.0–22.0% nickel. The high chromium resists scaling in air up to about 1,100 °C, well above what 304 or 316 can take. Annealed bar delivers 515 MPa minimum tensile strength, 205 MPa minimum yield and 40% minimum elongation to ASTM A276 Condition A. It is used for furnace rollers and fixtures, heat treatment baskets and trays, burner nozzles, radiant tubes and kiln and boiler components. 310S is the low-carbon version, with carbon at 0.08% maximum.
OneKaizen sources SS 310S from India's leading mills and international partner mills and supplies it as rolled round bars in Ø 16–500 mm, bright bars in Ø 8–160 mm, bright hex bars in 18–50 mm AF, hot rolled hex bars in 18–60 mm AF, square bars in 20–480 mm and forged bars in Ø 250–1,030 mm. Delivery condition is annealed, or hot rolled and pickled. Every consignment ships with a mill test certificate.
EQUIVALENT GRADES
SS 310 / 310S Equivalents
Direct means the same grade under another name. Close means the same alloy concept with slightly different limits, commonly substituted. Approximate means similar use with real differences: check with us before substituting.
| Standard | Designation | Match |
|---|---|---|
| BS 970 | 310S31 | Direct |
| EN | X8CrNi25-21 (1.4845) | Direct |
| DIN W.Nr. | 1.4845 | Direct |
| AISI/SAE | 310S | Direct |
| AISI/SAE | 310 | Direct |
| UNS | S31008 | Direct |
| UNS | S31000 | Direct |
| JIS | SUS310S | Direct |
| KS | STS310S | Direct |
| GB | 06Cr25Ni20 | Direct |
| UNI | X8CrNi25-21 | Direct |
SS 310 / 310S Chemical Composition
Per ASTM A276 (310S)
| Element | Range, wt % | Range chart |
|---|---|---|
| C | ≤ 0.08 | |
| Mn | ≤ 2 | |
| Si | ≤ 1.5 | |
| P | ≤ 0.045 | |
| S | ≤ 0.03 | |
| Cr | 24 – 26 | |
| Ni | 19 – 22 |
SS 310 / 310S and Its Equivalents: Chemical Composition
Equivalent grades are written to different standards, so their limits differ slightly. Use the column for the standard on your drawing or purchase order.
| Element | 310S ASTM A276 | 310 ASTM A276 | X8CrNi25-21 (1.4845) EN 10088-3 |
|---|---|---|---|
| C % | ≤ 0.08 | ≤ 0.25 | ≤ 0.10 |
| Si % | ≤ 1.50 | ≤ 1.50 | ≤ 1.50 |
| Mn % | ≤ 2.00 | ≤ 2.00 | ≤ 2.00 |
| P % | ≤ 0.045 | ≤ 0.045 | ≤ 0.045 |
| S % | ≤ 0.03 | ≤ 0.03 | ≤ 0.03 |
| Cr % | 24.00–26.00 | 24.00–26.00 | 24.00–26.00 |
| Ni % | 19.00–22.00 | 19.00–22.00 | 19.00–22.00 |
| N % | – | – | ≤ 0.11 |
SS 310 / 310S Mechanical Properties
| Condition | Tensile, MPa | Yield min, MPa | Elongation min, % | Hardness |
|---|---|---|---|---|
| Annealed (ASTM A276 Cond. A) | ≥ 515 | 205 | 40 | – |
Delivery Condition and Heat Treatment
SS 310S does not harden by heat treatment. We supply it annealed, or hot rolled and pickled, and the structure stays austenitic from room temperature to service temperature. That stability is what makes it good in furnaces: it keeps its toughness and does not turn brittle in the way ferritic and martensitic stainless steels can.
At room temperature its corrosion resistance is better than 410 and 420 but below 316, because it has no molybdenum. Choose it for heat, not for wet corrosion. In sulphur-bearing furnace atmospheres and under rapid thermal cycling, scale life falls, so tell us the duty and we will check the grade.
SS 310S welds by the usual arc processes using matching 310-type filler. The fully austenitic weld metal is prone to hot cracking, so keep heat input low and avoid heavy restraint. It work hardens in machining, so use sharp tools, a positive feed and rigid set-ups.
What We Supply SS 310 / 310S In
Where SS 310 / 310S Is Used
Industries: Heat treatment, Cement, Petrochemical, Power, Glass and ceramics
Compare SS 310 / 310S with Similar Grades
| SS 310 / 310S | SS 304 / 304L | SS 316 / 316L | |
|---|---|---|---|
| Why consider it | This grade | Lower cost below about 870 C | Better corrosion resistance at ambient temperature |
| C % | ≤ 0.08 | ≤ 0.08 | ≤ 0.08 |
| Mn % | ≤ 2 | ≤ 2 | ≤ 2 |
| Si % | ≤ 1.5 | ≤ 1 | ≤ 1 |
| Cr % | 24–26 | 18–20 | 16–18 |
| Ni % | 19–22 | 8–10.5 | 10–14 |
| Mo % | – | – | 2–3 |
SS 310 / 310S Questions
What is the maximum service temperature of SS 310?
About 1,100 °C in air for continuous oxidation resistance. Strength drops well before that temperature, so it resists scale at heat far better than it carries load there. If the part is loaded at temperature, tell us the load and temperature and we will confirm the grade.
What is the difference between SS 310 and 310S?
Carbon. 310S limits carbon to 0.08% maximum, and standard 310 allows a higher carbon content (0.25% maximum). 310S is the version we supply for most furnace work, because the lower carbon makes it easier to weld.
Should I use SS 310 or SS 304 for furnace parts?
Use 310S above about 870 °C. Below that temperature, 304 resists scaling well enough and costs less. Above it, 304 scales and loses strength quickly, while 310S carries on.
Is SS 310S magnetic?
No. SS 310S is fully austenitic and non-magnetic in the annealed condition. It does not harden by quenching either, so it behaves like 304 and 316 in that respect.
Is SS 310S the same as 1.4845?
Yes. 1.4845 (X8CrNi25-21) is the EN number for 310S, and SUS310S is the JIS equivalent. Both are direct matches.
What is the minimum order for SS 310S bars?
3 tonnes, flexible depending on grade, size and your situation. Send us your size, condition and quantity, with the form you need: round, bright, hex, square or forged bar.
What is SS 310 / 310S equivalent to?
SS 310 / 310S is the same grade as AISI/SAE 310S, AISI/SAE 310, UNS S31008, UNS S31000.
In which forms do you supply SS 310 / 310S?
OneKaizen supplies SS 310 / 310S as Round Bars, Bright Bars, Square Bars, Hex Bars, Forged Bars, SS 300 Series, delivered across India and exported to buyers abroad.
Do you supply SS 310 / 310S with a mill test certificate?
Yes. Every lot ships with an EN 10204 3.1 mill test certificate showing chemistry and mechanical properties, traceable to the heat number.
Data compiled by the OneKaizen metallurgy team from the standards named above. Updated 26 October 2026. Equivalents are nearest matches; confirm critical substitutions against the governing standard and mill certificate.