Acciai con contenuto di Cromo compreso tra il 16% e il 26%, Nichel tra il 7% e il 35% e Carbonio ( 0.15% max), che non possono essere induriti tramite trattamento di tempra, ma solo con deformazioni a freddo (es. trafilatura). Le loro caratteristiche principali sono la resistenza alla corrosione, generalmente più elevata degli altri acciai inox, ed un comportamento amagnetico.
| Valbruna Grade | W.N. | AISI | UNS | EN | BS |
|---|---|---|---|---|---|
| 214MNC | 1.4870 | - | - | X53CrMnNiNbN21-9 | 352S52 |
| 21MN | 1.4881 | - | - | X70CrMnNiN21-6 | - |
| ACNW | - | - | - | - | 331S40 |
| AIM/1 | - | 201 | S20100 | - | - |
| AIMR | - | XM-28 | S24100 | - | - |
| AIP | 1.4303 | 305 | S30500 | X4CrNi18-12/X5CrNi18-12 | - |
| AISC | 1.4550 / 1.4546 | 347 / 347H | S34700 / S34709 | X6CrNiNb18-10 / X5CrNiNb18-10 | 347S31 / 347S20 |
| AISH | 1.4948 | 304H | S30409 | X6CrNi18-10 / X6CrNi18-11 | - |
| AISH1 | 1.4948 | 304H | S30409 | X6CrNi18-10 / X6CrNi18-11 | - |
| AISH2 | - | 304H | S30409 | - | - |
| AISL | 1.4301/1.4307 | 304/304L | S30400/S30403 | X5CrNi18-10/X2CrNi18-9 | 304S15/304S31 |
| AISL/DE | 1.4306 | - | - | X2CrNi19-11 | - |
| AISLN | 1.4311 | 304LN | S30453 | X2CrNiN18-10 | - |
| AISN | - | XM-21 | S30452 | - | - |
| AISR/1 | 1.4301/1.4307 | 304/304L | S30400/S30403 | X5CRNI18-10/X2CRNI18-9 | 304S15/304S31 |
| AIST | 1.4541 | 321 | S32100 | X6CrNiTi18-10 | 321S31 |
| AISTH | 1.4878 / 1.4544 | 321H | S32109 | X8CrNiTi18-10 | - |
| AISWT | 1.4962 | - | - | X12CrNiWTiB16-13 | - |
| AMSL | - | 317L | S31703 | - | - |
| AMSL/DE | 1.4438 | - | - | X2CrNiMo18-15-4 | - |
| AMSL/DE2 | 1.4439 | - | - | X3CrNiMoN17-13-5 | - |
| APFI/SI | 1.4841 | 314 | S31400 | X15CrNiSi25-21 / X15CrNiSi25-20 | 314S25 |
| APFIS | 1.4845 | 310/310S | S31000/S31008 | X8CrNi25-21/X12CrNi25-21 | 310S31 |
| APFR | 1.4833 | 309 | S30900 | X12CrNi23-13 / X7CrNi23-14 | - |
| APFR/2 | - | EV4 | S63017 | - | 381S34 |
| APFR/SI | 1.4828 | - | - | X15CrNiSi20-12 | - |
| APM/DE2 | 1.4432 / 1.4436 | - | - | X2CrNiMo17-12-3 / X5CrNiMo17-13-3 | 316S33 / 316S14 |
| APMC/DE | 1.4580 | - | - | X10CrNiMoNb18-10 | - |
| APMH | - | 316H | S31609 | - | - |
| APML | 1.4401/1.4404 | 316/316L | S31600/S31603 | X5CrNiMo17-12-2/X2CrNiMo17-12-2 | 316S14/316S19 |
| APMLD2 | 1.4435 | - | - | X2CrNiMo18-14-3 | 316S13 / 316S14 / 316S33 |
| APMLDVAR | - | 316LN-IG | - | - | - |
| APMLN | 1.4429 | - | - | X2CrNiMoN17-13-3 | - |
| APMLN/DE | 1.4406 | 316N / 316LN | S31651 / S31653 | X2CrNiMoN17-11-2 | - |
| APMLNH | 1.4429 | 316LN | - | - | - |
| APMT | 1.4571 | 316TI | S31635 | - | - |
| APMT/DE | 1.4571 | - | - | X6CrNiMoTi17-12-2 | - |
| APMTH1 | 1.4571 | - | - | X6CrNiMoTi17-2-2 | - |
| AU188 | 1.4310 / 1.4300 / 1.4324 | 302 | S30200 | X10CrNi18-8 / X12CrNi18-8 | 302S31 / 301S22 |
| AU188Z | 1.4305 | 303 | S30300 | X8CrNiS18-9 | 303S31 |
| AU188ZU | 1.4570 | - | - | X6CrNiCuS18-9-2 | - |
| MV188HSE | 1.4305 | 303 | S30300 | X8CrNiS18-9 | 303S31 |
| NTR50 | - | XM-19 | S20910 | - | - |
| NTR60 | - | - | S21800 | - | - |
| S5220 | 1.4785 | - | - | X60CrMnMoVNbN21-10 | - |
| V2018MN | 1.4547 | F44 | S31254 | X1CrNiMoCuN20-18-7 | - |
| V2111N | 1.4835 | F45 | S30815 | X9CrNiSiNCE21-11-2 | - |