Material Properties AISI 4140 Steel Annealed admin May 20, 2016 Material Properties for AISI 4140 Steel Annealed Physical specifications of materials. Materials AISI 4140 Steel Description Annealed Density g/cc 7.85 lb/in^3 0.284 Hardness Brinell unless specified 197 Tensile Strength ultimate Mpa 655 Ksi 94.975 Yield Strength MPa 415 Ksi 60.175 Modulus of Elasticity Gpa 205 10^6 Psi 29.71014488 Poisson’s Ratio 0.29 %Elongation at break 25.7 %Reduction of area 56.9 Izod Impact J 62 Ft-lb 45.7436 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