The core difference between the two lies in the fact that 4340 steel contains a large amount of nickel (1.65-2.0%), while 4140 steel contains no nickel. This leads to a series of differences:
- Performance: 4340 has significantly better hardenability, strength (ultra-high strength grade), and toughness (especially at low temperatures) than 4140.
- Applications: 4140 is a general-purpose high-strength material for industrial parts, while 4340 is used for ultra-high strength components operating under harsh conditions.
- Cost: Due to its nickel content, 4340 has higher raw material and processing costs.Learn More