Steel grade equivalents: AISI, EN, JIS, GOST
The drawing calls for 1.4301 or 4140, but the supplier lists X5CrNi18-10 or a Russian grade. Find a grade in any system to see its equivalents and the ISO group used to choose inserts.
Quick answer
AISI 1045 = C45 (1.0503) = JIS S45C = GOST steel 45. 4140 = 42CrMo4 (1.7225), 304 = 1.4301, 316L ≈ 1.4404/1.4435, 52100 = 100Cr6, M2 = 1.3343. Equivalents are close, not identical: composition limits differ slightly between standards.
Structural and alloy steels
| AISI / SAE | EN | Material no. | JIS | GOST (Russia) | ISO | Typical use |
|---|---|---|---|---|---|---|
| A283 Gr. C | S235JR | 1.0038 | — | Ст3сп, Ст3пс | P | general purpose, welded structures |
| 1020 | C22 | 1.0402 | — | Сталь 20 | P | lightly loaded parts, case hardening |
| 1035 | C35 | 1.0501 | — | Сталь 35 | P | axles, bolts, studs |
| 1045 | C45 / C45E | 1.0503 / 1.1191 | S45C | Сталь 45 | P | shafts, axles, gears after heat treatment |
| 5140 | 41Cr4 | 1.7035 | SCr440 | 40Х | P | quenched and tempered shafts and gears |
| 4140 | 42CrMo4 | 1.7225 | SCM440 | ≈ 38ХМА | P | highly loaded parts |
| ≈ 4130 | ≈ 25CrMo4 | ≈ 1.7218 | ≈ SCM430 | 30ХГСА | P | high-strength parts; loose equivalents |
| 4340 | 34CrNiMo6 | 1.6582 | — | 34Х2Н2М | P | heavy-duty shafts |
| 52100 | 100Cr6 | 1.3505 | SUJ2 | ШХ15 | P / H | bearing steel; rollers, bushings, arbors |
Tool steels
| AISI / SAE | EN | Material no. | JIS | GOST (Russia) | ISO | Typical use |
|---|---|---|---|---|---|---|
| ≈ D2 | ≈ X153CrMoV12 | 1.2379 | ≈ SKD11 | Х12МФ | P / H | dies, knives, wear parts |
| ≈ O1 | ≈ 100MnCrW4 | ≈ 1.2510 | — | ХВГ | P / H | gauges and cutting tools |
| M2 | HS6-5-2 | 1.3343 | SKH51 | Р6М5 | P / H | high-speed steel: drills, taps, tool bits |
Stainless steels
| AISI / SAE | EN | Material no. | JIS | GOST (Russia) | ISO | Typical use |
|---|---|---|---|---|---|---|
| 304 | X5CrNi18-10 | 1.4301 | SUS304 | 08Х18Н10 | M | austenitic, the most common |
| 321 | X6CrNiTi18-10 | 1.4541 | SUS321 | 12Х18Н10Т | M | austenitic, Ti-stabilized, for heat and welding |
| 316L | X2CrNiMo17-12-2 / X2CrNiMo18-14-3 | 1.4404 / 1.4435 | SUS316L | 03Х17Н14М3 | M | austenitic with Mo, low carbon |
| 316Ti | X6CrNiMoTi17-12-2 | 1.4571 | SUS316Ti | 10Х17Н13М2Т | M | austenitic with Mo and Ti |
| 420 | X20Cr13 | 1.4021 | SUS420J1 | 20Х13 | P | martensitic: shafts, axles, hardenable |
| ≈ 420 | X46Cr13 | 1.4034 | ≈ SUS420J2 | 40Х13 | P | martensitic: cutting tools, springs |
| 430 | X6Cr17 | 1.4016 | SUS430 | 12Х17 | P | ferritic |
How to use equivalents
An equivalent is the closest grade, not the same steel: carbon, chromium and nickel limits differ slightly between standards. For machining that's usually enough — the same cutting data and inserts apply. For a critical part, check the chemistry and mechanical properties on the mill certificate for the actual heat.
≈ means a loose equivalent: sources call it "close", and the composition differs noticeably.
The ISO group points to the insert: P is steel, M austenitic stainless, H hardened steel (tool and bearing steels after hardening). More in ISO groups P, M, K, N, S, H; hardness after heat treatment — in the hardness conversion chart.
Equivalents cross-checked against several published charts (steel suppliers' tables and grade handbooks); only the 19 grades that matched across sources are listed. EN names per EN 10027, material numbers 1.xxxx per EN 10027-2.