Alloy Steel 4140
Alloy Steel 4140 is a chromium-molybdenum steel with excellent strength, toughness, and fatigue resistance. It is one of the most versatile alloy steels, used extensively for critical machine components that require through-hardening.
Machinability
66/100
Tolerance
±0.02 mm
Category
Carbon & Alloy Steel
Material Properties
| Property | Value |
|---|---|
| Tensile Strength | 655 MPa (95 ksi) |
| Yield Strength | 415 MPa (60 ksi) |
| Hardness | 197 HB |
| Density | 7.85 g/cm³ |
| Machinability Rating | 66/100 |
| Thermal Conductivity | 42.6 W/m·K |
| Melting Point | 1,416–1,460 °C |
| Tolerance | ±0.02 mm |
Common Grades
4140 Annealed4140 Pre-Hardened4140 Q&T
Advantages
- Excellent strength and toughness
- Through-hardenable
- Good fatigue resistance
- Versatile
Limitations
- Poor corrosion resistance
- Requires coating or plating
- Higher cost than plain carbon steel
Common Applications
Toolholders
Shafts
Gears
Collets
Sprockets
Couplings
Industries Served
Oil & GasAutomotiveIndustrial MachineryDefense
Compatible CNC Processes
CNC Milling
Tolerance: ±0.02 mm (±0.0008")
View Details→CNC Turning
Tolerance: ±0.02 mm (±0.0008")
View Details→4.5-Axis CNC Machining
Tolerance: ±0.02 mm
View Details→Wire EDM
Tolerance: ±0.02 mm
View Details→Rapid Prototyping
Tolerance: ±0.02 mm (prototype standard)
View Details→Surface Finishing
Tolerance: ±0.02 mm (±0.0008")
View Details→Available Surface Finishes
Black OxideZinc PlatingHard ChromeNitride