Steel 4130 Normalized
Heat-treated state
AISI/SAE 4130 · UNS G41300 · EN 1.7218, 25CrMo4 · JIS SCM430 · GB 30CrMo
Default stock condition for aircraft-quality 4130 sheet and seamless tube: uniform fine grain, good toughness and weldability at ~730 MPa.
Values for the Normalized condition
Other 4130 tempers and conditions
4130 is listed in 12 conditions; see the grade overview at 4130.
Compare all 12 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
full anneal ~845–870 °C, slow cool | Softest and most machinable/formable condition; use for deep machining, cold bending or as the starting point before hardening. | 361 | 560 | 28 | 156 HB | 43 W/m·K |
HRDefault Hot rolled | Cheapest mill condition for bar and plate that will be heat treated or machined afterwards; scaled surface and variable properties. | 440 | 700 | 22 | 210 HB | — |
NormalizedThis page 870–900 °C, air cooled (4130N) | Default stock condition for aircraft-quality 4130 sheet and seamless tube: uniform fine grain, good toughness and weldability at ~730 MPa. | 460 | 731 | 25 | 217 HB | — |
Normalized and tempered | Normalized then high-temper for lower hardness and better dimensional stability/toughness in welded or machined structures. | 500 | 670 | 26 | 13 HRC | 7.7 % IACS |
Cold drawn | Choose for straight, on-size shafting with good surface finish where no further heat treatment is planned. | 600 | 700 | 18 | 17 HRC | 43 W/m·K |
Cold rolled | Thin strip and sheet with tight thickness tolerance and smooth surface; strength raised and ductility cut by the cold reduction. | 690 | 810 | 12 | 22 HRC | 7.7 % IACS |
High-temper | Pick when hardness must stay ≤22–26 HRC for H₂S/sour service or maximum ductility in a hardened part. | 700 | 810 | 22 | 24 HRC | — |
Quenched and tempered | General-purpose hardened condition for shafts, fittings and pressure parts needing ~1000 MPa with retained toughness. | 910 | 1,030 | 18 | 31 HRC | — |
Tempered ~540 °C | Most common ordered hardness band for machined 4130 shafts, flanges and hydraulic bodies. | 910 | 1,030 | 18 | 30 HRC | — |
Tempered ~480 °C | Higher-strength band (~1150 MPa) for gears, sprockets and highly loaded fasteners where some toughness is still needed. | 1,040 | 1,150 | 16 | 34 HRC | — |
Tempered ~400 °C | Use for wear-loaded pins, tooling and drill components; toughness and weldability drop sharply at this hardness. | 1,150 | 1,280 | 14 | 42 HRC | — |
Oil/water quenched, tempered 205 °C | Maximum-strength condition (~1550 MPa) for small highly stressed parts; brittle, notch- and hydrogen-sensitive, not for welding. | 1,340 | 1,550 | 11 | 48 HRC | — |
What is 4130 Normalized?
4130 Normalized is 4130 heat treated to Normalized — default stock condition for aircraft-quality 4130 sheet and seamless tube: uniform fine grain, good toughness and weldability at ~730 MPa. 4130 Normalized has a yield strength of 460 MPa (66.7 ksi) and a tensile strength of 731 MPa (106 ksi) — stronger than 55% of steel grades. Elongation at break is 25% and the elastic modulus is 205 GPa (29.7 Msi). 4130 Normalized has a density of 7.85 g/cm³ (0.284 lb/in³), heavier than 56% of steel grades. It melts at 1,432°C (2,610 °F). HR is the default condition FabDigit quotes; Normalized is available on request or by drawing note.
Advantages
- Ductile — tolerates forming and impact — 25%, better than 77% of steel grades
4130 Normalized properties
Typical room-temperature values for 4130 Normalized; 13 are specific to this condition. Other listed values are 4130 reference data and may not represent this condition. Bars are the position among steel grades.
Physical3
4130 Normalized has a density of 7.85 g/cm³ (0.284 lb/in³), heavier than 56% of steel grades. It melts at 1,432°C (2,610 °F).
Mechanical16
4130 Normalized has a yield strength of 460 MPa (66.7 ksi) and a tensile strength of 731 MPa (106 ksi) — stronger than 55% of steel grades. Elongation at break is 25% and the elastic modulus is 205 GPa (29.7 Msi).
Thermal6
4130 Normalized is rated for continuous service to 400°C (752 °F). It conducts heat at 42.7 W/m·K (24.7 BTU/hr·ft·°F), better than 50% of steel grades. Thermal expansion is 12.2 µm/m·K (6.78 µin/in·°F).
Electrical3
4130 Normalized conducts electricity at 7.7 % IACS, worse than 65% of steel grades.
Chemical & Environmental3
Corrosion resistance is not recommended (14/100), better than 70% of steel grades.
Sustainability4
Producing a kilogram of 4130 Normalized takes about 30 MJ of energy and emits 2.3 kg of CO₂ — more than 56% of steel grades. Typical recycled content is 30%.
Manufacturability7
4130 Normalized's machinability is good (55/100, better than 62% of steel grades); weldability good (65/100); formability fair (45/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with 4130 Normalized
Is 4130 easy to machine?
Machines best annealed or normalized (~200 HB) with carbide at moderate speed and heavy positive feed; above 32 HRC expect tool wear, so rough before hardening and finish-grind after.
Can 4130 be welded?
Readily TIG/MIG welded with ER80S-D2 or ER70S-2 filler; preheat 150–250 °C for sections over ~3 mm, avoid quench-hard HAZ by slow cooling and stress relieve 590–650 °C, then re-normalize if full properties are required.
Can 4130 be formed, bent or molded?
Cold bend only in annealed/normalized thin sheet and tube with generous radii (≥3t); hot form 850–1150 °C and re-normalize afterwards, hardened material must not be cold formed.
What surface finishes work on 4130?
No natural corrosion resistance — specify zinc, cadmium or nickel plate, phosphate-and-oil, black oxide or epoxy paint; bake plated high-strength parts at 190 °C to relieve hydrogen.
4130 chemical composition (wt %)
Limits by weight percent from the governing specification, written the way the spec states them — a single maximum for impurities, a range for alloying elements, and the base element as balance. Nominal is the typical mid-range value.
| Element | Spec limit (wt %) | Nominal |
|---|---|---|
| CGB 30CrMo: 0.26–0.34 | 0.28 – 0.33 | 0.3 |
| Mn | 0.4 – 0.6 | 0.5 |
| Si | 0.15 – 0.35 | 0.25 |
| Cr | 0.8 – 1.1 | 0.95 |
| Mo | 0.15 – 0.25 | 0.2 |
| P | ≤ 0.04 | |
| Smax; 0.025 max for aircraft quality | ≤ 0.04 | |
| Fe | balance |
4130 Normalized — frequently asked
What is 4130 Normalized used for?
4130 Normalized is typically used for roll cages and tube space frames, aircraft engine mounts, high-pressure gas cylinders, drill collars and downhole tools, machine shafts and spindles and hydraulic cylinder rods. In short: tough aerospace chromoly.
What is the yield strength of 4130 Normalized?
4130 Normalized has a typical yield strength of 460 MPa (66.7 ksi) and a tensile strength of 731 MPa (106 ksi) — stronger than 55% of steel grades. Strength varies by condition: see the 12 listed tempers.
Is 4130 Normalized easy to machine?
Reasonably — machinability is rated good (55/100, better than 62% of steel grades). Machines best annealed or normalized (~200 HB) with carbide at moderate speed and heavy positive feed; above 32 HRC expect tool wear, so rough before hardening and finish-grind after.
Can 4130 Normalized be welded?
Yes — weldability is rated good (65/100). Readily TIG/MIG welded with ER80S-D2 or ER70S-2 filler; preheat 150–250 °C for sections over ~3 mm, avoid quench-hard HAZ by slow cooling and stress relieve 590–650 °C, then re-normalize if full properties are required.
What surface finishes work on 4130 Normalized?
No natural corrosion resistance — specify zinc, cadmium or nickel plate, phosphate-and-oil, black oxide or epoxy paint; bake plated high-strength parts at 190 °C to relieve hydrogen.
Can 4130 Normalized be formed, bent or molded?
Cold bend only in annealed/normalized thin sheet and tube with generous radii (≥3t); hot form 850–1150 °C and re-normalize afterwards, hardened material must not be cold formed.
What is the maximum service temperature of 4130 Normalized?
4130 Normalized is rated for continuous use to about 400°C (752 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between 4130-HR and 4130-CR?
HR is the default condition — cheapest mill condition for bar and plate that will be heat treated or machined afterwards; scaled surface and variable properties. CR: thin strip and sheet with tight thickness tolerance and smooth surface; strength raised and ductility cut by the cold reduction. Yield strength is 440 MPa in HR versus 690 MPa in CR.
Can FabDigit make parts in 4130 Normalized?
Yes — 4130 Normalized is available for CNC machining and sheet metal with instant online pricing. Upload a STEP file to get a price and a DFM check.
Sources
- ASTM A29/A29M — Steel Bars, Carbon and Alloy, Hot-Wrought — ASTM International (2020)
- ASTM A519 — Seamless Carbon and Alloy Steel Mechanical Tubing — ASTM International (2022)
- AMS 6345 / AMS 6360 — 4130 sheet, plate and tubing (normalized) — SAE International (2019)
- GB/T 3077 — (30CrMo) (2015)
- EN 10083-3 — Quenched and tempered steels, 25CrMo4 (1.7218) — CEN (2006)
- ASM Handbook Vol.1 — Properties and Selection: Irons, Steels and High-Performance Alloys — ASM International (1990)
- MMPDS-17 Metallic Materials Properties Development and Standardization — Battelle/FAA (2022)
- Atlas of Stress-Strain Curves / ASM Fatigue Data Book — ASM International (2002)
Property data is compiled from published supplier and standards handbooks and normalised for comparison. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.