Unified Numbering System
North American system: a letter for the family plus five digits – S stainless, N nickel, R reactive metals, C copper.
S31603 · N06625 · R50400Equivalents are nearest comparable grades, not identical materials. Chemical limits, mechanical properties, heat treatment and permitted elements differ between standards, and a grade acceptable in one code may not be acceptable in another. Always confirm the exact specification against the mill test certificate and your design code before substituting a grade.
How Grades Are Designated
The same steel carries a different name in every standards system. These are the seven systems used in the tables below – recognising them makes any enquiry or mill certificate readable.
SAE
AISI / SAE
The familiar three-digit stainless numbers and four-digit engineering steel numbers used across America and India.
316L · 4140 · D2Werkstoff Number
German material number, written as 1.XXXX for steels and 2.XXXX / 3.XXXX for non-ferrous alloys. Widely used on European certificates.
1.4404 · 1.7225 · 2.4856DIN
EN / DIN Name
The descriptive European name that spells out the chemistry – X2CrNiMo17-12-2 is 0.02% C, 17% Cr, 12% Ni, 2% Mo.
X2CrNiMo17-12-2 · 42CrMo4British Standard
BS 970 numbers for engineering steels (the origin of the EN8 / EN24 series) and the 300S / 316S codes for stainless.
817M40 (EN24) · 316S31AFNOR (France)
French designations that spell out the chemistry in letters – Z for stainless, C/CD/NCD for carbon, Cr-Mo and Ni-Cr-Mo steels – still common on European drawings.
Z3CND17-11-02 · 42CD4 · 35NCD6Japanese Industrial Standard
SUS for stainless, S__C for carbon steel, SCM / SNCM for alloy steels and SKD / SKS for tool steels.
SUS316L · SCM440 · SKD11Stainless & Duplex Steels
Austenitic, ferritic, martensitic and duplex stainless grades across the six systems.
| Grade | UNS | W.Nr. | EN / DIN name | BS | AFNOR (NF) | JIS |
|---|---|---|---|---|---|---|
| SS 304 Austenitic | S30400 | 1.4301 | X5CrNi18-10 | 304S31 | Z7CN18-09 | SUS 304 |
| SS 304L Austenitic | S30403 | 1.4307 (1.4306) | X2CrNi18-9 | 304S11 | Z3CN18-10 | SUS 304L |
| SS 303 Free-machining | S30300 | 1.4305 | X8CrNiS18-9 | 303S31 | Z8CNF18-09 | SUS 303 |
| SS 316 Austenitic | S31600 | 1.4401 | X5CrNiMo17-12-2 | 316S31 | Z7CND17-11-02 | SUS 316 |
| SS 316L Austenitic | S31603 | 1.4404 | X2CrNiMo17-12-2 | 316S11 | Z3CND17-11-02 | SUS 316L |
| SS 316Ti Stabilised | S31635 | 1.4571 | X6CrNiMoTi17-12-2 | 320S31 | Z6CNDT17-12 | SUS 316Ti |
| SS 317L Austenitic | S31703 | 1.4438 | X2CrNiMo18-15-4 | 317S12 | Z3CND19-15-04 | SUS 317L |
| SS 321 Stabilised | S32100 | 1.4541 | X6CrNiTi18-10 | 321S31 | Z6CNT18-10 | SUS 321 |
| SS 347 Stabilised | S34700 | 1.4550 | X6CrNiNb18-10 | 347S31 | Z6CNNb18-10 | SUS 347 |
| SS 309S Heat resisting | S30908 | 1.4833 | X12CrNi23-13 | 309S24 | Z15CN24-13 | SUS 309S |
| SS 310S Heat resisting | S31008 | 1.4845 | X8CrNi25-21 | 310S31 | Z12CN25-20 | SUS 310S |
| SS 410 Martensitic | S41000 | 1.4006 | X12Cr13 | 410S21 | Z12C13 | SUS 410 |
| SS 416 Free-machining | S41600 | 1.4005 | X12CrS13 | 416S21 | Z11CF13 | SUS 416 |
| SS 420 Martensitic | S42000 | 1.4021 | X20Cr13 | 420S37 | Z20C13 | SUS 420J1 |
| SS 430 Ferritic | S43000 | 1.4016 | X6Cr17 | 430S17 | Z8C17 | SUS 430 |
| SS 431 Martensitic | S43100 | 1.4057 | X17CrNi16-2 | 431S29 | Z15CN16-02 | SUS 431 |
| SS 904L Super austenitic | N08904 | 1.4539 | X1NiCrMoCu25-20-5 | 904S13 | Z2NCDU25-20 | SUS 890L |
| Duplex 2205 Duplex | S31803 / S32205 | 1.4462 | X2CrNiMoN22-5-3 | 318S13 | Z3CND22-05Az | SUS 329J3L |
| Super Duplex 2507 Super duplex | S32750 | 1.4410 | X2CrNiMoN25-7-4 | — | Z3CND25-06Az | — |
| Super Duplex S32760 Super duplex | S32760 | 1.4501 | X2CrNiMoCuWN25-7-4 | — | — | — |
Alloy, Carbon & Case-Hardening Steels
The EN-series engineering steels used across Indian industry, with their AISI/SAE, German and Japanese equivalents.
| Grade | BS 970 | AISI / SAE | W.Nr. | EN / DIN name | AFNOR (NF) | JIS |
|---|---|---|---|---|---|---|
| EN1A Free-cutting | 230M07 | 1213 | 1.0715 | 11SMn30 | S250 | SUM 22 |
| EN1A Leaded Free-cutting | 230M07Pb | 12L14 | 1.0718 | 11SMnPb30 | S250Pb | SUM 24L |
| EN3B Mild steel | 070M20 | 1020 | 1.0402 | C22 | XC18 | S20C |
| EN8 Medium carbon | 080M40 | 1040 | 1.0511 | C40 | XC38 / XC42 | S40C |
| C45 Medium carbon | 080M46 | 1045 | 1.0503 | C45 | XC45 / XC48 | S45C |
| EN16 Mn-Mo | 605M36 | — (no direct equivalent) | — | — | — | — |
| EN18 Cr steel | 530M40 | 5140 | 1.7035 | 41Cr4 | 42C4 | SCr 440 |
| EN19 / 4140 Cr-Mo | 709M40 | 4140 | 1.7225 | 42CrMo4 | 42CD4 | SCM 440 |
| EN24 / 4340 Ni-Cr-Mo | 817M40 | 4340 | 1.6582 (similar) | 34CrNiMo6 | 35NCD6 | SNCM 439 |
| EN31 / 52100 Bearing steel | 535A99 | 52100 | 1.3505 | 100Cr6 | 100C6 | SUJ 2 |
| EN36 Ni-Cr case-hardening | 655M13 | 3310 (similar) | 1.5752 | 14NiCr14 | 14NC11 (similar) | SNC 815 |
| EN41B Nitriding | 905M39 | Nitralloy 135M | 1.8509 | 41CrAlMo7-10 | 40CAD6-12 | SACM 645 |
| EN47 Spring steel | 735A51 | 6150 | 1.8159 | 51CrV4 | 50CV4 | SUP 10 |
| EN353 Case-hardening | 815M17 | 8620 (similar) | 1.6523 | 20NiCrMo2-2 | 16NCD13 (similar) | SNCM 220 |
| SAE 8620 Case-hardening | 805M20 | 8620 | 1.6523 | 20NiCrMo2-2 | 20NCD2 | SNCM 220 |
| 16MnCr5 Case-hardening | 527M17 (similar) | 5115 | 1.7131 | 16MnCr5 | 16MC5 | SCr 415 |
| 20MnCr5 Case-hardening | — | 5120 (similar) | 1.7147 | 20MnCr5 | 20MC5 | SCr 420 |
| ST52.3 Structural | — | A572 Gr. 50 (similar) | 1.0570 | S355J2 (St 52-3) | E36-3 (E355) | SM 490 |
Indian designations: EN8 ≈ 45C8, EN24 ≈ 40Ni2Cr1Mo28 and EN31 ≈ 103Cr1 under IS 1570 / IS 4398. Ask us for the IS equivalent of any other grade.
Tool & Die Steels
Cold work, hot work and mould steels in AISI, Werkstoff, DIN, BS and JIS designations.
| Grade | AISI | W.Nr. | DIN name | BS 4659 | AFNOR (NF) | JIS |
|---|---|---|---|---|---|---|
| D2 (HCHCr) Cold work | D2 | 1.2379 | X153CrMoV12 | BD2 | Z160CDV12 | SKD 11 |
| D3 (HCHCr) Cold work | D3 | 1.2080 | X210Cr12 | BD3 | Z200C12 | SKD 1 |
| OHNS Oil hardening | O1 | 1.2510 | 100MnCrW4 | BO1 | 90MWCV5 | SKS 3 |
| H11 Hot work | H11 | 1.2343 | X38CrMoV5-1 | BH11 | Z38CDV5 | SKD 6 |
| H13 Hot work | H13 | 1.2344 | X40CrMoV5-1 | BH13 | Z40CDV5 | SKD 61 |
| P20 Plastic mould | P20 | 1.2311 | 40CrMnMo7 | — | 35CMD7 (similar) | — |
| P20+Ni Plastic mould | P20 modified | 1.2738 | 40CrMnNiMo8-6-4 | — | 40CMND8 (similar) | — |
| DB6 Hot work die block | L6 (similar) | 1.2714 | 55NiCrMoV7 | BH224/5 | 55NCDV7 | SKT 4 |
| Silver Steel Ground bar | W1 (similar) | 1.2210 (similar) | 115CrV3 | BS 1407 | — | — |
| HSS M2 High speed | M2 | 1.3343 | HS6-5-2C | BM2 | Z85WDCV06-05-04-02 | SKH 51 |
Nickel Alloys & Titanium
Trade names, UNS numbers and their European equivalents.
| Grade | UNS | W.Nr. | EN / DIN name | BS | Type |
|---|---|---|---|---|---|
| Inconel 600 Ni-Cr-Fe | N06600 | 2.4816 | NiCr15Fe | NA 14 | Solid solution |
| Inconel 601 Ni-Cr-Fe-Al | N06601 | 2.4851 | NiCr23Fe | — | Heat resisting |
| Inconel 625 Ni-Cr-Mo-Nb | N06625 | 2.4856 | NiCr22Mo9Nb | NA 21 | Solid solution |
| Inconel 718 Ni-Cr-Nb | N07718 | 2.4668 | NiCr19Nb5Mo3 | — | Age hardening |
| Monel 400 Ni-Cu | N04400 | 2.4360 | NiCu30Fe | NA 13 | Solid solution |
| Monel K-500 Ni-Cu-Al-Ti | N05500 | 2.4375 | NiCu30Al | NA 18 | Age hardening |
| Hastelloy C-276 Ni-Mo-Cr | N10276 | 2.4819 | NiMo16Cr15W | — | Solid solution |
| Hastelloy C-22 Ni-Cr-Mo-W | N06022 | 2.4602 | NiCr21Mo14W | — | Solid solution |
| Incoloy 800 Ni-Fe-Cr | N08800 | 1.4876 | X10NiCrAlTi32-21 | NA 15 | Heat resisting |
| Incoloy 825 Ni-Fe-Cr-Mo | N08825 | 2.4858 | NiCr21Mo | NA 16 | Corrosion resisting |
| Titanium Grade 2 Commercially pure | R50400 | 3.7035 | Ti2 | — | CP titanium |
| Titanium Grade 5 Ti-6Al-4V | R56400 | 3.7165 | TiAl6V4 | — | Alpha-beta alloy |
Inconel®, Monel® and Incoloy® are trademarks of Special Metals Corporation; Hastelloy® is a trademark of Haynes International. Material is supplied to the UNS number and specification stated on your order.
Copper, Brass & Aluminium
North American UNS/alloy numbers alongside European designations.
| Grade | UNS / Alloy | EN number | EN / DIN name | W.Nr. | Notes |
|---|---|---|---|---|---|
| Copper ETP Electrolytic tough pitch | C11000 | CW004A | Cu-ETP | 2.0065 | ~100% IACS conductivity |
| Brass – free cutting CuZn36Pb3 | C36000 | CW603N | CuZn36Pb3 | 2.0375 | Machinability benchmark |
| Brass – 70/30 Cartridge brass | C26000 | CW505L | CuZn30 | 2.0265 | Deep drawing quality |
| Aluminium 6061 Al-Mg-Si-Cu | A96061 | EN AW-6061 | AlMg1SiCu | 3.3211 | General structural |
| Aluminium 6082 Al-Si-Mg-Mn | A96082 | EN AW-6082 | AlSi1MgMn | 3.2315 | Highest strength 6xxx |
| Aluminium 5083 Al-Mg | A95083 | EN AW-5083 | AlMg4.5Mn0.7 | 3.3547 | Marine grade |
| Aluminium 6063 Al-Mg-Si | A96063 | EN AW-6063 | AlMg0.7Si | 3.3206 | Extrusions, architectural |
"" isn't in the chart – but we can cross-reference it
This chart covers our most-requested grades. Send us the designation from your drawing, standard or mill certificate and we will identify the nearest equivalent we can supply – and confirm whether it is acceptable for your application.
Did you mean:
Using an Equivalent Safely
Four checks before accepting one grade in place of another.
Check the chemistry
Element ranges differ between standards – carbon, nitrogen and trace limits especially
Check the properties
Tensile, yield, hardness and impact requirements may not be identical
Check the code
Design codes list permitted materials – an equivalent may not be an approved substitute
Check the certificate
The mill certificate states what the material actually is – read it before accepting
Cross-Reference Enquiry
Have a Grade from a Foreign Drawing?
Send us the designation – from a drawing, a standard or an old mill certificate – and we'll identify what it is, what we can supply against it, and in which form and size.