EngiRef / Carbon Steel Properties

AISI 4340 Alloy Steel

AISI 4340 Alloy Steel (AISI 4340): carbon steel engineering material. Density 7850 kg/m³. Yield 862 MPa, ultimate 1110 MPa. Elastic modulus 205 GPa.

carbon-steel

Specification

Name
AISI 4340 Alloy Steel
Category
carbon-steel
Designation
AISI 4340
Applications
Aircraft landing gear, Power transmission gears, Shafts
Notes
Ni-Cr-Mo alloy. Very high strength. Excellent toughness and fatigue resistance.

Properties

Properties for AISI 4340 Alloy Steel
PropertyValue
Density7850 kg/m³
Tensile Strength Yield862 MPa
Tensile Strength Ultimate1110 MPa
Elastic Modulus205 GPa
Shear Modulus80 GPa
Poissons Ratio0.29
Thermal Conductivity44.5 W/(m·K)
Thermal Expansion12.3 µm/(m·K)
Specific Heat475 J/(kg·K)
Melting Point1427 °C
HardnessBrinell: 321, Rockwell C: C35