Corona SteelIndustry Pvt Ltd
FR

Choisir la langue

Recherche de produitsDemander un devis
FR

Choisir la langue

Menu
Plan du site07 entrées
Corona SteelFondée en 1955
Resources/Materials & grades/4130 / 25CrMo4

Materials & grades

4130 / 25CrMo4 / SCM430 chromium-molybdenum steel: equivalents 1.7218 and 30Cr4Mo2

4130 is a low-alloy chromium-molybdenum steel with about 0.30 % carbon, used normalized or hardened and tempered for tubing, shafts and welded structures. Its nearest equivalents are SCM430 in Japan and 25CrMo4 (1.7218) in Europe, but neither matches the 4130 limits exactly.

Names by standard

What it is called in each region

RegionSystemDesignationNormeMatch
USAAISI/SAE4130SAE J404; ASTM A29 (bar)Same material
UNSG41300—Same material
UKBS 970708A25Listed against 25CrMo4 and SAE 4130 by Saarstahl. Also listed as 708M25; the BS 970-1:1991 label is unconfirmed. BS 970 is withdrawn in favour of European standards.BS 970-1:1991Closest equivalent
EUEN 10027-1 name25CrMo4Carbon 0.22–0.29 %, manganese 0.60–0.90 %. Same name was used in the superseded DIN 17200.EN 10083-3; EN ISO 683-2Closest equivalent
EN 10027-2 number1.7218EN 10083-3Closest equivalent
EN 10027-1 name25CrMoS4 (1.7213)Resulphurised version for better machinability.EN 10083-3Closest equivalent
IndeIS 157030Cr4Mo2Nearest grade in the schedule: same carbon range (0.28–0.33 %), different manganese and molybdenum limits. No 25Cr4Mo2 appears in the Part 4 schedule.IS 1570 (Part 4):1988Closest equivalent
JapanJIS G 4053SCM430Same carbon range as 4130, but more chromium and a manganese range (0.60–0.90 %) that only touches 4130's (0.40–0.60 %) at 0.60 %.JIS G 4053Closest equivalent

On equivalence

  • 4130 and 25CrMo4 are close but not equal. 25CrMo4 has 0.22–0.29 % carbon against 0.28–0.33 % for 4130, and 0.60–0.90 % manganese against 0.40–0.60 %, so it reaches less strength for the same heat treatment. Saarstahl and Ovako both nonetheless name SAE 4130 as the nearest US grade.
  • SCM430 matches the 4130 carbon range but allows more manganese (0.60–0.90 %) and chromium (0.90–1.20 %). Kobelco's JIS G 4053 table gives the limits used here; Older JIS editions printed manganese 0.60–0.85 %, and the 2023 edition could not be read, so check the current edition before specifying.
  • Some cross-reference charts list SCM420 against 4130. SCM420 has 0.18–0.23 % carbon and is a case-hardening grade, so SCM430 is the right Japanese match.
  • Sources differ on two US limits. Ovako's ASTM A29 4130 row prints molybdenum 0.15–0.30 %, against 0.15–0.25 % here (AZoM, eFunda and the Central Steel & Wire catalog agree with 0.15–0.25 %). AZoM and eFunda print silicon 0.15–0.30 %, against 0.15–0.35 % here (Ovako and the Central Steel & Wire catalog). SAE J404 and ASTM A29 themselves were not read.
  • IS 1570 (Part 4) has no 25Cr4Mo2. Its schedule notes that 30Cr4Mo2 was added for use in the automobile and aircraft industries, and it is the nearest Indian grade. The Mo limit 0.15–0.28 % is as printed in IS 1570 and is probably a misprint for 0.25 %, since IS 11169 prints 0.15–0.25 % for 35Cr4Mo2. No source corrects it, so the printed figure is kept.
  • 708A25 is taken from Saarstahl's cross-reference for 25CrMo4; Swiss Steel / DEW and other charts write 708M25 instead, so the BS 970 label is unconfirmed. No UK composition limits are given here because no standard or mill source was found. UK buyers now order 25CrMo4 to EN ISO 683-2.
  • Aerospace material is bought to AMS specifications such as AMS 6348 (normalized bar), which set their own limits and heat treatment. The ASTM A29 limits above are for general-purpose bar.

Chemical composition

Composition limits, mass %

Element4130USA · ASTM A29 / SAE J404 (bar)25CrMo4 (1.7218)EU · EN 10083-3 (heat analysis)30Cr4Mo2Inde · IS 1570 (Part 4):1988SCM430Japan · JIS G 4053
C0.28–0.330.22–0.290.28–0.330.28–0.33
Si0.15–0.35≤0.400.10–0.350.15–0.35
Mn0.40–0.600.60–0.900.40–0.800.60–0.90
P≤0.035≤0.025—≤0.030
S≤0.040≤0.035—≤0.030
Cr0.80–1.100.90–1.200.80–1.100.90–1.20
Ni———≤0.25
Mo0.15–0.250.15–0.300.15–0.280.15–0.30

Mechanical properties

Strength and hardness

ConditionTensile strengthYield strengthElongationHardness
Cold drawn, normalizedTypical range for bar, not a specified minimumCentral Steel & Wire catalog, as tabulated on Wikipedia (41xx steel)590–760 MPa85–110 ksi480–590 MPa70–85 ksi20–30 %90–96 HRB
Annealed at 865 °C (1585 °F)Typical values, not specified minimums; bar size not stated. eFunda ties the tensile strength and hardness to the 865 °C anneal; its yield and elongation carry no condition.eFunda, AISI 4130 alloy steel560 MPa81.3 ksi361 MPa52.3 ksi28.2 %156 HB
Normalized at 870 °C (1600 °F), air cooledTypical values, not specified minimums; bar size not statedMatWeb, AISI 4130 Steel, normalized at 870 °C (1600 °F)670 MPa97.2 ksi435 MPa63.1 ksi25.5 %197 HB
Quenched and tempered (+QT)Specified, diameter under 16 mm; yield and elongation are minimumsEN 10083-3, 25CrMo4, via Saarstahl datasheet900–1100 MPa131–160 ksi≥700 MPa≥102 ksi≥12 %—
Quenched and tempered (+QT)Specified, diameter 16–40 mm; yield and elongation are minimumsEN 10083-3, 25CrMo4, via Saarstahl datasheet800–950 MPa116–138 ksi≥600 MPa≥87 ksi≥14 %—
Quenched and tempered (+QT)Specified, diameter 40–100 mm; yield and elongation are minimums. The Swiss Steel / DEW typical-values table prints 14 % elongation for this size.EN 10083-3, 25CrMo4, via Saarstahl datasheet700–850 MPa102–123 ksi≥450 MPa≥65 ksi≥15 %—
Quenched and tempered (+QT)Specified, diameter 100–160 mm; yield and elongation are minimumsEN 10083-3, 25CrMo4, via Saarstahl datasheet650–800 MPa94–116 ksi≥400 MPa≥58 ksi≥16 %—
Soft annealed (+A), 25CrMo4Specified maximum hardnessSaarstahl 25CrMo4 datasheet———≤212 HB
As rolled (+AR) and soft annealed (+A), SAE 4130 variantRound bar 14–70 mm; maximum hardnessOvako Steel Navigator, 34CrMo4 page (SAE4130m)———AR <260 HB; A <223 HB

In practice

Behaviour, heat treatment and uses

Characteristics

  • Lower carbon than 4140 (0.28–0.33 % against 0.38–0.43 %), so it is easier to weld and reaches less strength and hardness after quenching.
  • AZoM says it can be welded by all commercial methods. Ovako calls 25CrMo4 weldable under certain conditions, so preheat and post-weld heat treatment depend on section size and carbon equivalent.
  • Saarstahl describes 25CrMo4 as a tough chromium-molybdenum quench-and-tempered steel with good welding properties for tensile strengths of 700–950 MPa.
  • Machinability is rated 70 % of free-cutting 1212 in the annealed or cold-drawn condition (AZoM), falling as hardness rises.
  • Ovako lists 25CrMo4 for flame or induction hardening, austenitizing at 850–900 °C (1560–1650 °F) with a water spray.

Heat treatment

  • Forging or hot rolling: 1100–850 °C (2010–1560 °F) for 25CrMo4 (Saarstahl). AZoM gives a US forging range of 955–1205 °C (1750–2200 °F).
  • Normalizing: 860–890 °C (1580–1635 °F), cool in air (Saarstahl). Ovako gives 840–880 °C (1545–1615 °F).
  • Soft annealing: 680–720 °C (1255–1330 °F), furnace cool (Saarstahl). Ovako gives 700–730 °C (1290–1345 °F) for about 3 h.
  • Hardening: 840–880 °C (1545–1615 °F) in water or oil (Saarstahl). Ovako gives 840–870 °C (1545–1600 °F) for oil and 820–850 °C (1510–1560 °F) for water, then temper at once.
  • Tempering: 540–680 °C (1005–1255 °F) for the EN quenched-and-tempered conditions (Saarstahl). AZoM gives 400–565 °C (750–1050 °F) for US practice, which leaves higher strength and hardness.
  • Stress relieving: 525–620 °C (975–1150 °F), cool in air (Ovako).

Usages types

  • Aircraft engine mounts and welded tubing
  • Axles and steering knuckles
  • Turbine parts and rotors
  • Shafts and general machine parts that need toughness and some weldability

Alloy and case-hardening steels

Similar grades compared

GradeC %Mn %Cr %Ni %Tensile, first listed condition
4130 / 25CrMo40.28–0.330.40–0.600.80–1.10≤0.25590–760 MPa
4135 / 34CrMo40.33–0.380.70–0.900.80–1.10≤0.251000–1200 MPa
4140 / 42CrMo40.38–0.430.75–1.000.80–1.10≤0.25655 MPa
4340 / EN240.38–0.430.60–0.800.70–0.901.65–2.00745 MPa
5140 / 41Cr40.38–0.430.70–0.900.70–0.90≤0.25570 MPa
6150 / 51CrV40.48–0.530.70–0.900.80–1.10≤0.40670 MPa
16MnCr50.13–0.180.70–0.900.70–0.90≤0.25≥1000 MPa
20MnCr50.17–0.220.70–0.900.70–0.90≤0.25≥1200 MPa
655M13 / EN36A0.08–0.130.45–0.651.00–1.403.00–3.50700–770 MPa
8620 / 20NiCrMo2-20.18–0.230.70–0.900.40–0.600.40–0.70530 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 for its full table.

Questions et réponses

Common questions

What is the equivalent of 4130 steel?

The usual equivalents are SCM430 in Japan and 25CrMo4 (1.7218) in Europe, with 30Cr4Mo2 as the nearest Indian grade. SCM430 has the same carbon range as 4130; 25CrMo4 has less carbon and more manganese.

Is 4130 the same as 25CrMo4?

No, they are close equivalents. 4130 has 0.28–0.33 % carbon and 0.40–0.60 % manganese; 25CrMo4 has 0.22–0.29 % carbon and 0.60–0.90 % manganese. Both have about 1 % chromium and 0.2 % molybdenum.

What is the difference between 4130 and 4140?

4140 has more carbon (0.38–0.43 % against 0.28–0.33 %) and more manganese (0.75–1.00 % against 0.40–0.60 %). Chromium and molybdenum are the same. 4140 hardens deeper and reaches higher strength; 4130 is easier to weld.

Is 4130 weldable?

Yes. AZoM states it can be welded by all commercial methods, and welded tubing is one of its main uses. Thicker sections need preheat and often post-weld heat treatment to avoid a hard, brittle heat-affected zone.

What is the yield strength of 4130?

It depends on the condition. Cold-drawn normalized bar is typically 480–590 MPa (70–85 ksi) yield. Quenched and tempered 25CrMo4 to EN 10083-3 gives at least 600 MPa (87 ksi) yield with 800–950 MPa tensile in 16–40 mm sections.

From the Corona catalog

Need a part made to this specification?

Send the drawing, the material or grade, the finish, the quantity and the delivery country. The team reviews the requirement and the manufacturing route.

Démarrer une demande

Keep reading

4135 / 34CrMo44135 is a chromium-molybdenum steel with about 0.35 % carbon, hardened and tempered for crankshafts, axles and other highly stressed parts.4140 / 42CrMo4AISI 4140 is a medium-carbon chromium-molybdenum alloy steel, normally used hardened and tempered for shafts, gears and high-strength bolts.4340 / EN24AISI 4340 is a medium-carbon nickel-chromium-molybdenum alloy steel, used hardened and tempered where high strength and toughness are needed in large sections.1030 / C301030 is a plain medium-carbon steel with about 0.30 % carbon and 0.60–0.90 % manganese, used hot rolled, normalized or quenched and tempered for shafts, studs and general machined parts.Quenching and temperingQuenching and tempering hardens steel by cooling it rapidly from the austenite range to form martensite, then reheats it below Ac1 to trade some hardness for toughness.NormalizingNormalizing heats steel above its upper critical temperature and lets it cool in still air to give a fine, uniform ferrite–pearlite structure.AnnealingAnnealing heats steel to a set temperature, holds it and cools it slowly to make it softer, more ductile and easier to machine or cold form.SAE / AISI numbersA four-digit SAE/AISI number such as 1045 or 4140 names a carbon or alloy steel by its chemistry: the first two digits identify the steel family and the last two give the nominal carbon content in hundredths of a percent.EN 10027 names and numbersEuropean steels carry two identifiers under EN 10027: a steel name (Part 1) such as S235JR, C45 or 42CrMo4 that describes the steel's use or chemistry, and a material number (Part 2) such as 1.0503 or 1.7225.BS 970 and the EN seriesBS 970 names steels with a six-character code such as 080M40, in which the first three digits give the steel type, the letter says how the steel is specified and the last two digits give the carbon content.IS 1570 and Indian designationsIndian steel names follow the letter-symbol code in IS 1762 (Part 1), which the IS 1570 schedules use: 45C8 means about 0.45% carbon, C for carbon steel and about 0.8% manganese, while alloy names such as 40Cr4Mo3 list each element with a multiplied content figure.JIS steel designationsJapanese JIS steel symbols start with S for steel and add letters for the steel family or its use, but the number means different things in different standards.

References

Sources

  1. Ovako Steel Navigator: 25CrMo4 — EN ISO 683-2 composition, +QT properties, heat treatment, SAE 4130 and 1.7218 cross-reference.
  2. Ovako Steel Navigator: 34CrMo4 (includes SAE 4130 ASTM A29 row) — ASTM A29 4130 composition and weldability indices; SAE4130m hardness.
  3. Saarstahl material specification sheet: 25CrMo4 (1.7218) — +QT properties by diameter, heat treatment, BS 708A25 and SAE 4130 cross-reference.
  4. Kobelco: Wire rods and bars specification tables (JIS G 4053) — SCM430 composition from the JIS G 4053 table (2008 revision).
  5. Bureau of Indian Standards, IS 1570 (Part 4):1988 Schedules for wrought steels, alloy steels (Public.Resource.Org copy) — Table 1 composition for 30Cr4Mo2 and the note on why it was added.
  6. SAE Mobilus: AMS6348 Steel, bars, 0.95Cr-0.20Mo (0.28 to 0.33C) (SAE 4130), normalized — Aerospace bar specification for 4130.
  7. AZoM: AISI 4130 alloy steel (UNS G41300) — US heat treatment, machinability, weldability, other designations.
  8. Wikipedia: 41xx steel (SAE composition table citing the Central Steel & Wire catalog) — SAE 4130 composition and cold-drawn normalized properties.
  9. ICAST: EN 10083-3 1.7218 datasheet — EN composition cross-check.
  10. MatWeb: AISI 4130 Steel, normalized at 870°C (1600°F) — Normalized typical values with the condition stated: 670 MPa tensile, 435 MPa yield, 25.5 % elongation, 197 HB.
  11. eFunda: AISI 4130 alloy steel properties — Annealed (865 °C) typical values: 560.5 MPa tensile, 360.6 MPa yield, 28.2 % elongation, 156 HB.
  12. Swiss Steel / Deutsche Edelstahlwerke datasheet: 25CrMo4 (1.7218) — Typical +QT values (14 % elongation at 40–100 mm), 708M25 and 1.7218 cross-reference.

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