EN9    Technical Data EN9 is an unalloyed medium carbon steel. It is supplied at the hardness obtained after hot rolling or cold drawing, with a hardness normally within the range of 180 to 230HB. EN9 is available from stock in bar and can be cut to your requirements. We also offer EN9 plate flame cut to your required sizes and normalised. TYPICAL ANALYSIS   C. Si. Mn. S. P. 0.50% 0.25% 0.70% 0.05% 0.05% Forging: Heat slowly and uniformly to 1100°C. After forging cool slowly. Annealing:  Heat uniformly to 700°C. Soak well and cool slowly in the furnace.  Hardening: Heat uniformly to 820/840°C until heated through. Quench in oil, or water. Tempering: Heat uniformly and thoroughly at the selected tempering temperature, between 550/660°C and hold at heat for one hour per inch of total thickness.  Hard Chromium Plating: After hard chromium plating, the steel should be tempered for approximately 4 hours at 180°C, in order to avoid hydrogen embrittlement. Welding: Firstly heat to approximately 100-350°C.  Use an unalloyed basic electrode, for welding unalloyed structural steels. Normalising: Normalise at 840-870°C, and cool in air. Stress Relieving: After rough machining tools should be stress relieved.  Soaking time 2 hours after the whole piece has attained a temperature of approximately 675°C. Cool in furnace to approximately 500°C, and then freely in air.      Physical Properties: Density Coefficient of Thermal Expansion Modulus of Elasticity kg/m per c from 20 c N/mm 7800 11.6x10-6 206000   Available sections: