Material Properties AISI 4340 Steel Oil Quenched admin May 20, 2016 Material Properties for AISI 4340 Steel Oil Quenched Physical specifications of materials. Materials AISI 4340 Steel Description Oil Quenched Density g/cc 7.85 lb/in^3 0.284 Hardness Brinell unless specified 352 Tensile Strength ultimate Mpa 1207 Ksi 175.015 Yield Strength MPa 1145 Ksi 166.025 Modulus of Elasticity Gpa 205 10^6 Psi 29.71014488 Poisson’s Ratio 0.29 %Elongation at break 14.2 %Reduction of area 45.9 Izod Impact J Ft-lb Fracture Toughness Mpa(m)^0.5 Ksi(in)^0.5 Thermal conductivity W/m-K 44.5 Btu/ft-h-F 25.722543349 Specific Heat Cpacity J/g-K 0.475 Btu/lb-F 0.114 Coefficient of thermal expansion 1E-6/K 12.3 1E-6/F 6.8436090171 Electrical Resistivity Ohm-cm 0.0000248