Material Properties AISI 4140 Steel Oil Quenched admin May 20, 2016 Material Properties for AISI 4140 Steel Oil Quenched Physical specifications of materials. Materials AISI 4140 Steel Description Oil Quenched Density g/cc 7.85 lb/in^3 0.284 Hardness Brinell unless specified 311 Tensile Strength ultimate Mpa 1075 Ksi 155.875 Yield Strength MPa 986 Ksi 142.97 Modulus of Elasticity Gpa 205 10^6 Psi 29.71014488 Poisson’s Ratio 0.29 %Elongation at break 15.5 %Reduction of area 56.9 Izod Impact J Ft-lb Fracture Toughness Mpa(m)^0.5 Ksi(in)^0.5 Thermal conductivity W/m-K 42.6 Btu/ft-h-F 24.6242774532 Specific Heat Cpacity J/g-K 0.473 Btu/lb-F 0.11352 Coefficient of thermal expansion 1E-6/K 12.2 1E-6/F 6.7879699194 Electrical Resistivity Ohm-cm 0.000022