The following is a comparison of 4130 grade steel and 4140 grade steel. This information may be useful for machining purposes and as a resource for purchasing 4130 and 4140 steel.
Chemical Properties
The chemical properties of 4130 and 4140 steel are similar aside from differences in Carbon and Manganese concentrations.
| 4130 | 4140 | |
| Carbon, C | 0.30% | 0.40% |
| Manganese, Mn | 0.40-0.60% | 0.75-1.00% |
| Chromium, Cr | 0.80-1.10% | 0.80-1.10% |
| Molybdenum, Mo | 0.15-0.25% | 0.15-0.25% |
Mechanical Properties
The following are the mechnical properties for both normalized and annealed 4130 and 4140 steel.
Normalized
| 4130 | 4140 | |
| Tensile Strength | 97,000 psi | 148,000 psi |
| Yield Strength | 63,000 psi | 95,000 psi |
| Elongation (2″) | 25.5% | 17.7% |
| Reduction in Area | 59.5% | 46.8% |
| Brinell Hardness | 197 | 302 |
Annealed
| 4130 | 4140 | |
| Tensile Strength | 81,300 psi | 95,000 psi |
| Yield Strength | 52,300 psi | 60,500 psi |
| Elongation (2″) | 28.2% | 25.7% |
| Reduction in Area | 55.6% | 56.9% |
| Brinell Hardness | 156 | 197 |
The relative machinability Rating percentage based on SAE1212 as 100% is the following for cold drawn 4130 and cold drawn 4140 steel
- 4130 – 70%
- 4140 – 65%
