Stainless steel grades, with the evidence for each

Last verified 19 August 2026. Generated from the data files, so it cannot fall out of step with the grade pages.

Read the fourth column before the third

The Rp0.2 column is the one people scan and it is the one that misleads, because the figures in it are not the same kind of object. Some are minima a standard sets. Some are typical values a mill measures and prints without promising them. Some are quoted for cold rolled sheet and some for Quarto plate, which on one grade moves the number by a fifth. Two of them are not room temperature figures at all.

7 grades here carry more than one proof strength figure — 17-4 PH, 17-7 PH, Duplex 2205, 316L, 410, 420, 441 — under a second standard, a second product form or a second test orientation. The table shows one row each. The grade page shows every figure with the document and the form it belongs to, and the gap between two of them is rarely what it looks like and sometimes not about the material at all.

So this table is a directory, not a ranking. It is deliberately not sorted by strength, and the pairwise pages will refuse to compare a typical value against a specified minimum rather than print a verdict. Why that distinction is the expensive one, and what the evidence levels mean.

The grades

Austenitic stainless steel

Grade	UNS	EN	Rp0.2	What that figure is	PREN	Evidence	Values / gaps
304	S30400	1.4301	230 MPa	minimum · EN 10088-2 · cold rolled coil and sheet	18	E3	7 / 2
304L	S30403	1.4307	220 MPa	minimum · EN 10088-2 · cold rolled coil and sheet	18	E3	7 / 3
316	S31600	1.4401	240 MPa	minimum · EN 10088-2 · cold rolled coil and sheet	24	E3	7 / 3
316L	S31603	1.4404	240 MPa	minimum · EN 10088-2 · cold rolled coil and sheet	24	E3	8 / 1
316Ti	S31635	1.4571	240 MPa	minimum · EN 10088-2 · cold rolled coil and sheet	24	E3	7 / 3
317L	S31703	1.4438	220 MPa	minimum · EN 10088-2 · Quarto plate	28	E3	7 / 3
317LMN	S31726	1.4439	290 MPa	minimum · EN 10088-2 · cold rolled coil and sheet	33	E3	7 / 3
321	S32100	1.4541	220 MPa	minimum · EN 10088-2 · cold rolled coil and sheet	17	E3	7 / 3
347	S34700	1.4550	220 MPa	minimum · EN 10088-2 · cold rolled coil and sheet	18	E3	7 / 3

Duplex stainless steel

Grade	UNS	EN	Rp0.2	What that figure is	PREN	Evidence	Values / gaps
Duplex 2205	S32205	1.4462	500 MPa	minimum · EN 10088-2 · cold rolled coil and sheet	35	E3	8 / 1

Ferritic stainless steel

Grade	UNS	EN	Rp0.2	What that figure is	PREN	Evidence	Values / gaps
441	S43932	1.4509	250 MPa	minimum · EN 10088-2 · cold rolled coil and sheet	18	E3	8 / 4
444	S44400	1.4521	300 MPa	minimum · EN 10088-2 · cold rolled coil and sheet	25	E3	6 / 3

Heat-resistant austenitic stainless steel

Grade	UNS	EN	Rp0.2	What that figure is	PREN	Evidence	Values / gaps
253 MA	S30815	1.4835	230 MPa	minimum · EN 10095 · 100 °C	not established	E3	7 / 4
310S	S31008	1.4845	140 MPa	minimum · EN 10095 · 100 °C	not established	E3	7 / 4

High-alloy austenitic stainless steel

Grade	UNS	EN	Rp0.2	What that figure is	PREN	Evidence	Values / gaps
904L	N08904	1.4539	240 MPa	minimum · EN 10088-2 · cold rolled coil and sheet	34	E3	7 / 3
Alloy 28	N08028	1.4563	250 MPa	minimum · EN 10088-2 · Quarto plate	34	E3	7 / 3

Lean duplex stainless steel

Grade	UNS	EN	Rp0.2	What that figure is	PREN	Evidence	Values / gaps
2101	S32101	1.4162	530 MPa	minimum · EN 10088-2 · cold rolled coil and sheet	26	E3	7 / 3
2304	S32304	1.4362	450 MPa	minimum · EN 10088-2 · cold rolled coil and sheet	26	E3	7 / 3

Martensitic stainless steel

Grade	UNS	EN	Rp0.2	What that figure is	PREN	Evidence	Values / gaps
410	S41000	1.4006	340 MPa	measured · Outokumpu Dura range datasheet · wire rod	not established	E3	7 / 4
420	S42000	1.4021	500 MPa	measured · Outokumpu Dura range datasheet · wire rod	not established	E3	7 / 4

Precipitation hardening stainless steel

Grade	UNS	EN	Rp0.2	What that figure is	PREN	Evidence	Values / gaps
17-4 PH	S17400	1.4542	850 MPa	measured · Outokumpu Dura range datasheet · wire rod	not established	E3	7 / 4
17-7 PH	S17700	1.4568	210 MPa	measured · Outokumpu Dura range datasheet · wire rod	not established	E3	7 / 4

Super duplex stainless steel

Grade	UNS	EN	Rp0.2	What that figure is	PREN	Evidence	Values / gaps
Super duplex 2507	S32750	1.4410	550 MPa	minimum · EN 10088-2 · cold rolled coil and sheet	43	E3	7 / 2

Super-austenitic stainless steel

Grade	UNS	EN	Rp0.2	What that figure is	PREN	Evidence	Values / gaps
254 SMO	S31254	1.4547	320 MPa	minimum · EN 10088-2 · cold rolled coil and sheet	43	E3	7 / 3
4565	S34565	1.4565	420 MPa	minimum · EN 10088-2 · cold rolled coil and sheet	46	E3	7 / 3
654 SMO	S32654	1.4652	430 MPa	minimum · EN 10088-2 · Quarto plate	56	E3	7 / 3
6XN	N08367	1.4562	300 MPa	minimum · EN 10088-2 · Quarto plate	45	E3	7 / 3

Where the numbers come from

Every value on every grade page resolves to a document in a registry of 12 sources, and each one records whether we opened it ourselves. Values resting on a document nobody read are demoted automatically and the page says so — which is why nothing here is above E3 and why the two values that claim more do not get it. The full count — what we hold, what we could not establish and the concentration of sources behind it — is in the audit. Our coverage and its limits.

Selecting for a job rather than comparing two grades? The application pages start from the failure mode instead of the alloy. Head-to-head pages are in the comparison index. If you are earlier than that — still deciding what the part has to survive rather than which two grades to weigh against each other — start with how a selection is actually run.

What this page does not cover

Composition limits, on any grade. The datasheets give typical compositions, which are not the limits a purchase order specifies.
Corrosion rate data, critical pitting temperatures and crevice behaviour — the properties high-alloy grades are actually selected on.
Fatigue, fracture toughness, creep and stress corrosion cracking.
Welding, forming and heat treatment guidance.
Any recommendation. A directory of what the documents say is not a selection.

Generated from data/materials/*.yaml. Regenerate rather than editing this file by hand — edits here are lost on the next build.