1045 equivalent grades: ASTM, EN, JIS, GB, DIN
1045 is medium-carbon steel, hardenable specified in ASTM A29. Every grade in the database that can stand in for it is listed below, drawn from 5 standard systems, each with the reason it does or does not match exactly. The full 1045 data sheet carries the composition and mechanical tables.
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1045 is cross-certified with 080M46, C45, 45 and 1 more: the composition windows overlap closely enough that one certificate satisfies the other. 1050, 1040 differ on one limit only — a carbon ceiling, an impact temperature or a strength minimum. 4140, 1144, 080M40 serve the same purpose without being the same steel, so a substitution there needs the design re-checked rather than the certificate. Across systems that is 2 in BS (superseded British), 1 in EN (European), 1 in GOST (Russia/CIS), 1 in JIS (Japan), 4 in AISI / SAE.
Cross-reference table
| Grade | System | Match | Why / differences |
|---|---|---|---|
| 080M46 | BS (superseded British) | Identical | BS 970 080M46: C 0.42–0.50, Mn 0.60–1.00. |
| C45 | EN (European) | Identical | 1.0503: C 0.42–0.50, Mn 0.50–0.80; C45E (1.1191) the cleaner version — dual-certified 1045/C45 bar is standard. |
| 45 | GOST (Russia/CIS) | Identical | GOST 1050 Steel 45: C 0.42–0.50, Mn 0.50–0.80. |
| S45C | JIS (Japan) | Identical | JIS G4051 S45C: C 0.42–0.48, Mn 0.60–0.90. |
| 1050 | AISI / SAE | Near | C 0.48–0.55: slightly higher carbon and hardness for the same treatments. |
| 1040 | AISI / SAE | Near | C 0.37–0.44: slightly lower carbon, better weldability. |
| 4140 | AISI / SAE | Functional | Alloyed alternative with deep hardenability for sections > 25 mm and higher toughness. |
| 1144 | AISI / SAE | Functional | Resulfurized 0.44 % C free-machining bar ('Stressproof') for high-volume screw-machine shafts. |
| 080M40 | BS (superseded British) | Functional | AISI 1045 is 0.43–0.50 % C — the American counterpart of 080M46. Against 080M40 it is one carbon step higher; AISI 1040 is the true match, at 0.37–0.44 % C. |
Identical, near and functional are defined once on the grade index; the reason column below says which limit differs in each case.
1045 in BS (superseded British)
- 080M46 — Identical BS 970 080M46: C 0.42–0.50, Mn 0.60–1.00.
- 080M40 — Functional AISI 1045 is 0.43–0.50 % C — the American counterpart of 080M46. Against 080M40 it is one carbon step higher; AISI 1040 is the true match, at 0.37–0.44 % C.
1045 in EN (European)
- C45 — Identical 1.0503: C 0.42–0.50, Mn 0.50–0.80; C45E (1.1191) the cleaner version — dual-certified 1045/C45 bar is standard.
1045 in GOST (Russia/CIS)
- 45 — Identical GOST 1050 Steel 45: C 0.42–0.50, Mn 0.50–0.80.
1045 in JIS (Japan)
- S45C — Identical JIS G4051 S45C: C 0.42–0.48, Mn 0.60–0.90.
1045 in AISI / SAE
- 1050 — Near C 0.48–0.55: slightly higher carbon and hardness for the same treatments.
- 1040 — Near C 0.37–0.44: slightly lower carbon, better weldability.
- 4140 — Functional Alloyed alternative with deep hardenability for sections > 25 mm and higher toughness.
- 1144 — Functional Resulfurized 0.44 % C free-machining bar ('Stressproof') for high-volume screw-machine shafts.
Superseded names for 1045
- C1045 — AISI (pre-1960s)
- G10450 — UNS: 1045H = H10450 hardenability band.
- 080M46 / 080A47 — BS 970: 080M46 ≈ 1045 (Mn 0.60–1.00).
- C45 / Ck45 / C45E — EN 10083 / DIN 17200: European twins.
- XC45 / XC48 — NF A 35-552
Key data for 1045
Full composition, mechanical properties by thickness, heat treatment and applications for 1045 →
Verified against ASTM A29/A29M-20 (SAE J403 chemistry). Last checked: September 2026.