Steel 4130-CR (Cold rolled)
Supply condition
AISI/SAE 4130 · UNS G41300 · EN 1.7218, 25CrMo4 · JIS SCM430 · GB 30CrMo
Thin strip and sheet with tight thickness tolerance and smooth surface; strength raised and ductility cut by the cold reduction.
Values for the CR 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 | — |
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 |
CRThis page 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-CR?
4130-CR is 4130 supplied in the CR condition — thin strip and sheet with tight thickness tolerance and smooth surface; strength raised and ductility cut by the cold reduction. 4130-CR has a yield strength of 690 MPa (100 ksi) and a tensile strength of 810 MPa (117 ksi) — stronger than 80% of steel grades. Elongation at break is 12% and the elastic modulus is 205 GPa (29.7 Msi). 4130-CR 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; CR is available on request or by drawing note.
Advantages
- High strength — 690 MPa (100 ksi), better than 80% of steel grades
Limitations
- Limited ductility — 12%, worse than 84% of steel grades
- Limited service temperature — 300°C (572 °F), worse than 78% of steel grades
4130-CR properties
Typical room-temperature values for 4130-CR; 23 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-CR 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-CR has a yield strength of 690 MPa (100 ksi) and a tensile strength of 810 MPa (117 ksi) — stronger than 80% of steel grades. Elongation at break is 12% and the elastic modulus is 205 GPa (29.7 Msi).
Thermal6
4130-CR is rated for continuous service to 300°C (572 °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-CR 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-CR 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-CR's machinability is good (58/100, better than 75% of steel grades); weldability good (60/100); formability poor (30/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with 4130-CR
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-CR — frequently asked
What is 4130-CR used for?
4130-CR 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-CR?
4130-CR has a typical yield strength of 690 MPa (100 ksi) and a tensile strength of 810 MPa (117 ksi) — stronger than 80% of steel grades. Strength varies by condition: see the 12 listed tempers.
Is 4130-CR easy to machine?
Reasonably — machinability is rated good (58/100, better than 75% 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-CR be welded?
Yes — weldability is rated good (60/100). 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-CR?
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-CR 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-CR?
4130-CR is rated for continuous use to about 300°C (572 °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-CR?
Yes — 4130-CR 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.