Data completeness: partial. Last verified 19 August 2026.
Designations
| Common name | 253 MA |
| UNS | S30815 |
| EN number | 1.4835 |
| Class | Heat-resistant austenitic stainless steel |
| Specified by | EN 10095 |
253 MA reaches a higher service temperature than 310S while carrying roughly half the nickel, and it does that with silicon and a rare earth addition rather than with alloy bulk. Cerium keeps the oxide scale adherent through thermal cycling; nitrogen strengthens the austenite so the alloy stays useful hot instead of merely intact. On the elevated temperature rows it is materially stronger than 310S at every temperature both are quoted at.
Properties, with what each one rests on
| Property | Value | Unit | Condition | Evidence | Source | Retrieved |
|---|---|---|---|---|---|---|
| Maximum service temperature in air | 1150 | °C | continuous service in air, supplier recommendation | E3 | Outokumpu Therma range datasheet — heat-resistant stainless steels | 2026-08-20 |
| Proof strength Rp0.2, minimum at 100 °C | 230 | MPa | 100 °C | E3 | EN 10095 via Outokumpu Therma range datasheet — heat-resistant stainless steels | 2026-08-20 |
| Proof strength Rp0.2, minimum at 600 °C | 140 | MPa | 600 °C | E3 | EN 10095 via Outokumpu Therma range datasheet — heat-resistant stainless steels | 2026-08-20 |
| Tensile strength Rm, minimum at 600 °C | 445 | MPa | 600 °C | E3 | EN 10095 via Outokumpu Therma range datasheet — heat-resistant stainless steels | 2026-08-20 |
| Density | 7.8 | g/cm³ | 20 °C | E3 | Outokumpu Therma range datasheet — heat-resistant stainless steels | 2026-08-20 |
| Modulus of elasticity | 200 | GPa | 20 °C | E3 | Outokumpu Therma range datasheet — heat-resistant stainless steels | 2026-08-20 |
| Thermal conductivity | 15 | W/(m·K) | 20 °C | E3 | Outokumpu Therma range datasheet — heat-resistant stainless steels | 2026-08-20 |
| Room temperature mechanical minima | not established | — | — | — | the datasheet consulted carries no room temperature mechanical table for the heat-resistant range | — |
| Creep rupture strength | not established | — | — | — | not in the datasheet consulted, and above roughly 600 °C it is the property that governs design | — |
| Composition limits | not established | — | — | — | the datasheet gives typical values, which are not limits, and EN 10095 is paywalled | — |
| Cyclic oxidation data | not established | — | — | — | resistance to cycling is the argument for the rare earth addition, and the datasheet asserts it without quantifying it | — |
7 sourced values, 4 gaps named. Publishing the gaps is more useful than filling them from an aggregator that does not say where its numbers came from. The routes to filling them are the standard itself, a mill datasheet, or a mill certificate for your actual heat — which supersedes both at E5.
Where the numbers come from
Maximum service temperature in air. A hundred degrees above 310S on the same datasheet page, from an alloy with about half the nickel. As with every figure in that column it is the mill’s recommendation for air, not a limit from a standard, and it does not travel to another atmosphere.
Proof strength Rp0.2, minimum at 100 °C. The table is headed as EN 10095 minimum values. This is 64% above the 310S row at the same temperature, and the nitrogen in the composition is the reason.
Proof strength Rp0.2, minimum at 600 °C. Still above what the same EN 10095 table gives 310S at 100 °C. If a hot part is strength-driven rather than scale-driven, this is the row that decides it.
Why we do not just copy an aggregator. Because then this page would be a worse copy of MatWeb with no way for you to tell which rows to trust, and the one thing we have that MatWeb does not is the evidence column. Our coverage and its limits.
What 253 MA is usually chosen for
Hot parts that cycle. Furnace fans, recuperators, burner and boiler components, radiant tubes and anything that is heated and cooled repeatedly rather than held at temperature. It is also chosen over 310S when the nickel price is the problem, since it delivers a higher ceiling on roughly half the nickel.
And what it is usually rejected for
Sulphur-bearing and strongly carburising atmospheres, and any duty where creep rather than scaling governs — above roughly 600 °C creep rather than yield is the design property, and no source consulted for this page supplies it. It is also a specialist grade with thinner availability than 310S, and machining the silicon-bearing composition is harder work.
The number to be more careful with than any of the above is the difference between a specified minimum and a typical value — a floor the standard guarantees, versus what a supplier’s production usually does. The full version, and the most expensive routine mistake in material data.
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What this page does not cover
- No room temperature values at all, which is the datasheet’s position, not an omission on this page.
- No creep or creep rupture data.
- The cyclic oxidation advantage is asserted by the source, not quantified, and is therefore not a row in the table above.
- The maximum service temperature is a supplier recommendation for air, not a standard limit.
- Composition limits, not established.
Generated from data/materials/253ma.yaml. Regenerate rather than editing this file by hand — edits here are lost on the next build.