Data completeness: partial. Last verified 19 August 2026.
Designations
| Common name | 2101 |
| UNS | S32101 |
| EN number | 1.4162 |
| Class | Lean duplex stainless steel |
| Specified by | ASTM A240/A240M, EN 10088-2 |
2101 is the lean duplex built around manganese and nitrogen instead of nickel — about 1.5% Ni against the 8% or more an austenitic needs. That is a deliberate answer to nickel price volatility, and it works: the cold rolled proof strength minimum is the highest of the lean duplexes in the datasheet consulted, above 2304 and above 2205 on the same row.
Properties, with what each one rests on
| Property | Value | Unit | Condition | Evidence | Source | Retrieved |
|---|---|---|---|---|---|---|
| Proof strength Rp0.2, minimum (EN) | 530 | MPa | cold rolled coil and sheet, 20 °C | E3 | EN 10088-2 via Outokumpu Forta range datasheet — duplex and high-strength stainless steels | 2026-08-20 |
| Tensile strength Rm, minimum | 700 | MPa | cold rolled; datasheet gives a 700–900 range | E3 | EN 10088-2 via Outokumpu Forta range datasheet — duplex and high-strength stainless steels | 2026-08-20 |
| Elongation A, minimum | 30 | % | cold rolled, gauge length 5.65√S0; the A80 value on the same row is 20% | E3 | EN 10088-2 via Outokumpu Forta range datasheet — duplex and high-strength stainless steels | 2026-08-20 |
| PREN | 26 | — | from typical composition, not from a heat | E3 | Outokumpu Forta range datasheet — duplex and high-strength stainless steels | 2026-08-20 |
| Density | 7.8 | g/cm³ | 20 °C | E3 | Outokumpu Forta range datasheet — duplex and high-strength stainless steels | 2026-08-20 |
| Modulus of elasticity | 200 | GPa | 20 °C | E3 | Outokumpu Forta range datasheet — duplex and high-strength stainless steels | 2026-08-20 |
| Thermal conductivity | 15 | W/(m·K) | 20 °C | E3 | Outokumpu Forta range datasheet — duplex and high-strength stainless steels | 2026-08-20 |
| Composition limits | not established | — | — | — | ASTM A240 is paywalled; the datasheet gives typical values, which are not limits | — |
| Impact toughness and the transition temperature | not established | — | — | — | not in the datasheet consulted | — |
| Maximum service temperature | not established | — | — | — | not in the datasheet consulted; the duplex ceiling applies but this page cannot supply the number | — |
7 sourced values, 3 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
Proof strength Rp0.2, minimum (EN). Above the 2205 cold rolled row in the same table, which is counter-intuitive and worth checking against your own product form before using: Quarto plate for this grade is 450 MPa, and the same standard governs both numbers.
Elongation A, minimum. The clearest example on this site of a number that changes with how it was measured rather than with the material. A and A80 differ by half on one row of one datasheet, because the gauge length differs. Quoting “30% elongation” without saying which is not wrong so much as meaningless.
PREN. 21.5% Cr, 0.3% Mo and 0.22% N give 26.0 in the datasheet’s own formula. Identical to 2304 by a different route — 2304 gets there on chromium, 2101 on nitrogen.
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 2101 is usually chosen for
Structural stainless where the budget is exposed to the nickel price and the environment is mild to moderate. Reinforcement bar, tanks, containers, structural sections and rail vehicle bodies. The strength lets a designer take thickness out, and the lean composition takes the volatility out of what remains.
And what it is usually rejected for
Aggressive chlorides and difficult fabrication. At the same pitting ranking as 2304 it is well short of 2205, and nothing about the lean composition changes that. It also work hardens fast, needs more power to form and cut than an austenitic, and demands a controlled welding window like every duplex.
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.
Compare
What this page does not cover
- The temperature ceiling is real but not established here as a number.
- Impact toughness and the transition temperature.
- Forming and welding guidance, both of which differ materially from austenitic practice.
- Composition limits, not established.
- Crevice corrosion, which the pitting ranking number does not predict.
Generated from data/materials/2101.yaml. Regenerate rather than editing this file by hand — edits here are lost on the next build.