Material Properties Gray Cast Iron Astm Class 35 admin May 20, 2016 Material Properties for Gray Cast Iron Astm Class 35 Physical specifications of materials. Materials Gray Cast Iron Description Astm Class 35 Density g/cc 7.15 lb/in^3 0.258 Hardness Brinell unless specified 212 Tensile Strength ultimate Mpa 252 Ksi 36.54 Yield Strength MPa Ksi Modulus of Elasticity Gpa 114 10^6 Psi 16.521739104 Poisson’s Ratio 0.29 %Elongation at break %Reduction of area Izod Impact J Ft-lb Fracture Toughness Mpa(m)^0.5 Ksi(in)^0.5 Thermal conductivity W/m-K 50 Btu/ft-h-F 28.9017341 Specific Heat Cpacity J/g-K Btu/lb-F Coefficient of thermal expansion 1E-6/K 13.5 1E-6/F 7.5112781895 Electrical Resistivity Ohm-cm 0.00008