We supply a lots of 4130 and 4340 steel grades to our customers all over the world. You will find the chemical and mechanical properties comparison between steel 4130 vs 4340 steel grades as below. And it may help for machining purposes and as a reference for your purchasing 4130 steel and 4340 steel.
4130
4130 steel, as low alloy steel, contains high amounts of chromium and is often referred to as chromoly. 4130 steel has good machinability, ductility, weldability and strength characteristics. 4130 steel is used for many different industries including the automotive, aerospace and machining industries.
4340
4340 steel, as nickel-chromium-molybdenum alloy steel, is a very high strength steel. It is sought after for its toughness and for being used as a steel that will be highly stressed.
4340 steels are used in a variety of industries for different applications including the automotive, aerospace, and tooling industries.
Chemical Composition Comparison: 4130 vs 4340 steel
| Standard | Grade | C | Mn | P | S | Si | Cr | Mo | Ni |
| ASTM A29 | 4340 | 0.38-0.43 | 0.60-0.80 | 0.035 | 0.040 | 0.15-0.35 | 0.70-0.90 | 0.20-0.30 | 1.65-2.00 |
| 4130 | 0.28-0.33 | 0.40-0.60 | 0.035 | 0.040 | 0.15-0.35 | 0.80-1.10 | 0.15-0.25 |
Mechanical Properties: 4130 vs 4340 steel
Below are the mechanical properties for both normalized and annealed 4130 steel and 4340 steel.
- Normalized
| 4130 | 4340 | |
| Tensile Strength | 97,000 psi | 185,500 psi |
| Yield Strength | 63,000 psi | 125,000 psi |
| Elongation (2″) | 25.5% | 12.2% |
| Reduction in Area | 59.5% | 36.3% |
| Brinell Hardness | 197 | 363 |
- Annealed
| 4130 | 4340 | |
| Tensile Strength | 81,300 psi | 108,000 psi |
| Yield Strength | 52,300 psi | 68,500 psi |
| Elongation (2″) | 28.2% | 22.0% |
| Reduction in Area | 55.6% | 49.9% |
| Brinell Hardness | 156 | 217 |
You could find the detailed properties each for grade 4130 steel and 4340 steel below:
