Materials & grades

1050 / C50 / S50C medium-carbon steel: equivalents 50C8, 080M50 (EN43A) and C50E

1050 is a plain medium-carbon steel with about 0.50 % carbon and 0.60–0.90 % manganese, used normalized or quenched and tempered for shafts, gears and parts that are flame or induction hardened. Its close equivalents are C50 / C50E (1.0540 / 1.1206) in Europe, 080M50 (old EN43A) in the UK, 50C8 in India and S50C in Japan.

Names by standard

What it is called in each region

RegionSystemDesignationStandardMatch
USAAISI/SAE1050Composition limits shown are SAE J403 (P ≤0.030 %). ASTM A29 and older AISI tables give P ≤0.040 %.SAE J403; ASTM A29 / A108Same material
UNSG10500—Same material
UKBS 970080M50Listed against C50E by Saarstahl and against S50C by Misumi. Carbon 0.45–0.55 % and manganese 0.60–1.00 %, wider than 1050. BS 970 has been withdrawn in favor of European standards.BS 970-1Closest equivalent
BS 970 legacy EN seriesEN43ASuperseded name for 080M50 per Alan Bright Steel and Hillfoot. TSM Steel labels 080M50 as EN43B, so sources disagree.—Closest equivalent
EUEN 10027-1 nameC50Carbon 0.47–0.55 %, manganese 0.60–0.90 %.EN ISO 683-1 (formerly EN 10083-2)Equivalent
EN 10027-2 number1.0540Material number of C50.EN ISO 683-1Equivalent
EN 10027-1 nameC50E (1.1206) / C50R (1.1241)Variants with tighter phosphorus and sulfur (E) or a controlled sulfur range (R).EN ISO 683-1Equivalent
DIN (legacy)Ck50 / Cm50Superseded German names for C50E and C50R.—Equivalent
IndiaIS 157050C8Carbon 0.45–0.55 %, manganese 0.60–0.90 %. IS 1570 gives no tensile table for 50C8.IS 1570 (Part 2/Sec 1)Closest equivalent
IS 157050C4Same carbon but a lower manganese range of 0.30–0.60 %. The tensile properties in IS 1570 are given for this grade.IS 1570 (Part 2/Sec 1)Closest equivalent
IS 1570 (old designation)C50 (50C4)Superseded Indian name for 50C4, with low manganese. It is not the same as EN C50.—Closest equivalent
JapanJIS G 4051S50CCarbon 0.47–0.53 %, a narrower range than 1050.JIS G 4051Closest equivalent

On equivalence

  • 1050 and C50 are close equivalents, not the same specification. C50 allows 0.47 % minimum carbon against 1050's 0.48 %; manganese is 0.60–0.90 % in both. EN ISO 683-1 also specifies mechanical properties by condition and size.
  • Some tables map 080M50 and C50E to SAE 1049 as well as 1050 (Saarstahl lists both); 1049 is a separate SAE grade with a slightly lower carbon range.
  • UK sources disagree on the legacy name. Alan Bright Steel, Hillfoot and a cross-reference table give EN43A for 080M50; TSM Steel gives EN43B. The separate EN43 spring steel is a different grade.
  • 080M50 allows manganese up to 1.00 % and carbon from 0.45 %, so its limits are wider than those of 1050.
  • Indian 50C8 (Mn 0.60–0.90 %) matches 1050 more closely than 50C4 (Mn 0.30–0.60 %). IS 1570 gives tensile properties for 50C4, not 50C8, and its old name C50 is not the same as EN C50.
  • S50C has a narrower carbon range (0.47–0.53 %) than 1050. The S50C silicon, manganese, phosphorus and sulfur limits are from ASM Alloy Digest; carbon, chromium and chromium-plus-nickel limits are from Total Materia (JIS G 4051:2023). Xometry's S50C datasheet quotes ≥630 MPa, but those are the Chinese GB 50 normalized values (25 mm specimen), not JIS figures.

Chemical composition

Composition limits, mass %

Element1050USA · SAE J403080M50UK · BS 970C50 (1.0540)EU · EN 10083-2 / EN ISO 683-1C50E (1.1206)EU · EN 10083-2 / EN ISO 683-150C8India · IS 1570 (Part 2/Sec 1):197950C4India · IS 1570 (Part 2/Sec 1):1979S50CJapan · JIS G 4051
C0.48–0.550.45–0.550.47–0.550.47–0.550.45–0.550.45–0.550.47–0.53
Si—0.10–0.40≤0.40≤0.40——0.15–0.35
Mn0.60–0.900.60–1.000.60–0.900.60–0.900.60–0.900.30–0.600.60–0.90
P≤0.030≤0.050≤0.045≤0.030——≤0.030
S≤0.050≤0.050≤0.045≤0.035——≤0.035
Cr——≤0.40≤0.40——≤0.20
Ni——≤0.40≤0.40———
Mo——≤0.10≤0.10———
Cr+Mo+Ni——≤0.63≤0.63———
Cr+Ni——————≤0.35

Mechanical properties

Strength and hardness

ConditionTensile strengthYield strengthElongationHardness
Hot rolled (1050)Estimated minimum, bars about 19–32 mm (3/4–1-1/4 in), SAE J1397 basisSAE J1397 estimates as published by ICAST90 ksi (620 MPa)49 ksi (340 MPa)15 %179 HB
Cold drawn (1050)Estimated minimum, bars about 19–32 mm (3/4–1-1/4 in), SAE J1397 basisSAE J1397 estimates as published by ICAST and AZoM100 ksi (690 MPa)84 ksi (580 MPa)10 %197 HB
Normalized +N (C50E)Specified minimum, d 16–100 mmEN 10083-2 as tabulated by Roymech and Saarstahl≥88 ksi (≥610 MPa)≥46 ksi (≥320 MPa)14 %—
Quenched and tempered +QT (C50E)Specified, d 16–40 mmEN 10083-2 as tabulated by Roymech and Saarstahl102–123 ksi (700–850 MPa)≥67 ksi (≥460 MPa)15 %—
Hot rolled or normalized (50C4)Specified range, ruling sections up to 150 mmIS 1570 (Part 2/Sec 1):1979, Table 296–113 ksi (660–780 MPa)—13 %—
Hardened and tempered (50C4), lower rangeSpecified, limiting ruling section 63 mmIS 1570 (Part 2/Sec 1):1979, Table 4102–123 ksi (700–850 MPa)≥67 ksi (≥460 MPa)15 %—
Hardened and tempered (50C4), higher rangeSpecified, limiting ruling section 30 mmIS 1570 (Part 2/Sec 1):1979, Table 4116–138 ksi (800–950 MPa)≥78 ksi (≥540 MPa)13 %—
Normalized (S50C)JIS G 4051 reference minimums; the standard gives these for guidance, not as acceptance valuesJIS G 4051 reference values (minimums), as reproduced by toishi.info, materialmechanics.work and hayamihyou.net; normalized tensile agrees with Total Materia≥88 ksi (≥610 MPa)≥52 ksi (≥365 MPa)≥18 %179–235 HB
Quenched and tempered (S50C)JIS G 4051 reference minimums; the standard gives these for guidance, not as acceptance valuesJIS G 4051 reference values (minimums), as reproduced by toishi.info, materialmechanics.work and hayamihyou.net; normalized tensile agrees with Total Materia≥107 ksi (≥740 MPa)≥78 ksi (≥540 MPa)≥15 %212–277 HB

In practice

Behavior, heat treatment and uses

Characteristics

  • Higher strength and wear resistance than 1045, with lower ductility and toughness.
  • Moderate hardenability: 1050 hardens deeper than 1030 or 1035 but is still best for sections of modest size.
  • Flame or induction hardening gives a hard surface with moderate wear resistance over an unchanged core (West Yorkshire Steel, 080M50).
  • Weldability is poor to fair. Preheat, low-hydrogen electrodes and stress relief are needed, and welding in the hardened condition is not recommended.
  • Machinable in the annealed or normalized condition; it is hard to cut after quenching.

Heat treatment

  • Forging or rolling: about 1100–850 °C (2010–1560 °F) (Saarstahl, C50E).
  • Normalizing: about 830–870 °C (1525–1600 °F) (Saarstahl) or 810–860 °C (1490–1580 °F) for S50C (Total Materia). Cool in air.
  • Soft annealing: about 680–710 °C (1255–1310 °F), furnace cool (Saarstahl).
  • Hardening: about 810–850 °C (1490–1560 °F) with an oil or water quench (Saarstahl); 800–850 °C (1470–1560 °F) for 080M50 (West Yorkshire Steel).
  • Tempering: about 550–660 °C (1020–1220 °F), cool in air (Saarstahl; West Yorkshire Steel).

Typical uses

  • Shafts, axles and spindles
  • Gears and sprockets that are flame or induction hardened
  • Crankshafts, tie rods and connecting rods
  • Hammers, bushes and wear parts (listed for 080M50 by West Yorkshire Steel)
  • General forgings and machined components needing more strength than 1045

Carbon steels

Similar grades compared

GradeC %Mn %Cr %Ni %Tensile strength, first listed condition
1050 / C500.48–0.550.60–0.90≤0.40≤0.4090 ksi (620 MPa)
1030 / C300.28–0.340.60–0.90≤0.40≤0.4068 ksi (470 MPa)
1035 / C350.32–0.380.60–0.90≤0.40≤0.4073 ksi (500 MPa)
1040 / C40 / EN80.37–0.440.60–0.90≤0.40≤0.4076 ksi (524 MPa)
1045 / C450.43–0.500.60–0.90≤0.40≤0.4082 ksi (565 MPa)
1055 / C550.50–0.600.60–0.90≤0.40≤0.4094 ksi (650 MPa)
1008≤0.100.30–0.50——44 ksi (303 MPa)
1010 / C10E0.08–0.130.30–0.60≤0.30—46 ksi (320 MPa)
1015 / C15E0.13–0.180.30–0.60≤0.30—49 ksi (340 MPa)
10180.15–0.200.60–0.90≤0.20—58 ksi (400 MPa)

Composition from the US standard where one exists, otherwise the first standard listed on each grade's page. Strength conditions differ between grades; open a grade's page for its full table.

Questions answered

Common questions

What is the equivalent of 1050 steel?

C50 / C50E (1.0540 / 1.1206) in Europe, 080M50 in the UK, 50C8 in India and S50C in Japan. They are close equivalents with slightly different composition limits, not identical specifications.

Is 1050 the same as C50?

No, but they are close. C50 has 0.47–0.55 % carbon and 0.60–0.90 % manganese. 1050 has 0.48–0.55 % carbon and 0.60–0.90 % manganese.

What is the British equivalent of 1050?

080M50 under BS 970, formerly EN43A in the legacy series. Its limits are wider (0.45–0.55 % carbon, 0.60–1.00 % manganese). BS 970 is withdrawn, and UK buyers now usually order C50E to EN ISO 683-1.

What is the difference between 1045 and 1050?

1050 has about 0.05 % more carbon, so it reaches higher strength and surface hardness after heat treatment but is less ductile and harder to weld. Both are used for shafts and flame or induction hardened parts.

Is S50C equivalent to 1050?

Yes, as a close equivalent. S50C (JIS G 4051) has 0.47–0.53 % carbon and 0.60–0.90 % manganese, which falls inside or very near the 1050 limits.

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References

Sources

  1. IS 1570 (Part 2/Sec 1):1979 Schedules for wrought steels: carbon steels (public copy) — 50C8 and 50C4 composition, hot-rolled and hardened-and-tempered properties.
  2. Saarstahl material specification sheet: C50E (1.1206) — Heat treatment, +N and +QT properties; lists BS 080M50 and SAE 1049, 1050.
  3. Roymech: EN 10083 steels for quenching and tempering — C50E composition and +N / +QT properties.
  4. AZoM: AISI 1050 Carbon Steel (UNS G10500) — Composition and cold-drawn properties.
  5. ICAST: SAE J403 / SAE J1397 UNS G10500, Hot Rolled — SAE J403 composition and J1397 estimated properties.
  6. ICAST: SAE J403 / SAE J1397 UNS G10500, Cold Drawn
  7. West Yorkshire Steel: 080M50 carbon steel — 080M50 composition, heat treatment and typical uses.
  8. Hillfoot: 080M50 medium carbon steel — Describes 080M50 as the successor of EN43A.
  9. TSM Steel: 080M50 (EN43B) datasheet — Same composition; labels the grade EN43B.
  10. Alan Bright Steel: comparison of world steel standards — BS 970 original, 1983 and 1991 editions to AISI cross-reference (080M50 as EN43A).
  11. Total Materia: JIS S50C (JIS G 4051:2023) — C, Cr and Cr+Ni limits, tensile, hardness, heat treatment, cross-references to 080M50 and C50E.
  12. ASM Alloy Digest: S50C and S53C (JIS G 4051 composition) — Si, Mn, P, S limits.
  13. Xometry: S50C datasheet — Composition including Cr, Ni, Cu maxima. Secondary source.
  14. MISUMI: JIS and foreign standards comparison for machine structural steels — S50C against 1049, C50 and 080M50.
  15. toishi.info — JIS S-C carbon steel mechanical properties (normalized and quenched-and-tempered) — S30C, S35C, S50C and S55C pages, read by the independent checker
  16. materialmechanics.work — JIS G 4051 S-C mechanical properties

Values summarize published limits and typical data. The governing standard and the current edition control; check them before specifying.