Alloy Steel 4140
Material Data Sheet
AISI 4140 steel is a low alloy steel containing chromium, molybdenum, and manganese. It is widely used across numerous industries and is an excellent material choice due to its toughness, high fatigue strength, and abrasion and impact resistance. Not many grades can match the versatility and usefulness of 4140.
Chemical Composition
| Chemistry | Content(%) |
|---|---|
| Iron, Fe | 96.78 |
| Chromium, Cr | 0.8 |
| Manganese, Mn | 0.75 |
| Carbon, C | 0.38 |
| Silicon, Si | 0.15 |
| Molybdenum, Mo | 0.15 |
| Sulfur, S | 0.040 |
| Phosphorous, P | 0.035 |
Physical Properties
| Properties | Metric | Imperial |
|---|---|---|
| Density | 7.85 g/cm³ | 0.284 lb/in³ |
| Melting Point | 1416 °C | 2580 °F |
Mechanical Properties
| Properties | Metric | Imperial |
|---|---|---|
| Tensile Strength | 655 MPa | 95000 psi |
| Yield Strength | 415 MPa | 60200 psi |
| Bulk Modulus | 140 GPa | 20300 ksi |
| Shear Modulus | 80 GPa | 11600 ksi |
| Elastic Modulus | 190 – 210 GPa | 27557 – 30458 ksi |
| Poisson’s Ratio | 0.27 – 0.30 | 0.27 – 0.30 |
| Elongation at Break | 25.70% | 25.70% |
| Hardness, Brinell | 197 | 197 |
| Harndess, Knoop | 219 | 219 |
| Hardness, Rockwell B | 92 | 92 |
| Hardness, Rockwell C | 13 | 13 |
| Hardness, Vickers | 207 | 207 |
| Machinability | 65 | 65 |
Applications
Alloy Steel 4140 is used in the following application areas:
- Shafts
- Crankshafts
- Bolts/Nuts
- Gears
- Milling spindles
- Collars
- Jigs
- Steel conveyor and roll
- Fixtures
- Steel coupling
