AISI 4140 ALLOY STEEL | 42CRMO4| SCM440|EN19
As Chrome-Moly High Tensile Steel,The chromium content in AISI 4140 steel provides good hardness penetration, and the molybdenum content ensures uniform hardness and high strength. AISI 4140 offers a very good balance of strength, toughness and wear-resistance.
AISI 4140 steel can be oil hardened to a relatively high level of hardness with a tensile strength of 850 – 1000 MPa.Pre hardened and tempered 4140 can be further surface hardened by flame or induction hardening(can be surface hardened to a typical value 58HRC)and by nitriding( Surface hardness achievable is 600 to 650HV).
AISI 4140 Steel Chemical Composition
| Grade | C | Si | Mn | P | S | Cr | Mo |
| 4140 | 0.38-0.43 | 0.15-0.35 | 0.75-1.00 | ≤0.035 | ≤0.04 | 0.8-1.1 | 0.15-0.25 |
AISI 4140 Steel Related Specifications
| Europe | UK | China | Japan |
| 42CrMo4/1.7225 | EN19/709M40 | 42CrMoA | SCM440 |
AISI 4140 Steel Heat Treatment & Mechanical Property
- Forging: 1100℃-1200℃,cooling in sand after forged is recommended
- Normalizing:870℃-900℃,Cool in air
- Annealing:800℃-850℃,Cool in furnace
- Hardening:840℃-875℃,oil or water quench
- Tempering:450°C – 700°C, cool in still air
- Nitriding:Heat to 500°C – 530°C and hold for sufficient time to develop the depth of case required
- Flame and Induction Hardening:All materials consisting of de-carburized surfaces should be removed to ensure best results.Heat quickly to the required case depth at 860°C – 890°C and soak instantly in water or oil.Tempering at 150°C – 200°C helps reduce stresses in the case with marginal effect on its hardness
AISI 4140 steel Mechanical Property In Quenched & Tempered Condition
| Ruling Section mm | <254 | <127 |
| Tensile Strength Mpa | 690 | 862 |
| Yield Strength Mpa | 552 | 758 |
| Elongation % | >20 | >13 |
| Reduction of Area % | >40 | >40 |
| Charpy Impact -46°C, J | >42 | >27 |
| Hardness HB | 217-235 | 285-341 |
AISI 4140 Steel Quality Certification
A material test report(Inspection Certificate EN 10204 3.1) will be provided, documenting the following:
1.Chemical analysis
2.Mechanical properties
3.Surface hardness
4.Non metallic inclusion
5.Heat treatment report
6.Grain size
7.Forging ratio
8.Ultrasonic test report
Supply Size & Condition For AISI 4140
- Round Bars: Dia.80 – 1,000mm as Forged
- Flat / Square Bars: Thickness Max.800mm
- Shafts, Rollers, Blocks: Customized or According to Drawing
- Rolled Round Bars: Dia.14 – 350mm with UT Assurance
Heat treatment:Quenched and Tempered (+QT), Normalizing (+N), Annealing (+A)
Surface finish:Black / Rough turned / Peeled
