EN24   817M40  Technical Data EN24 is a high quality, high tensile, alloy steel . Usually supplied readily machineable in ‘T’ condition, it combines high tensile strength, shock resistance, good ductility and resistance to wear TYPICAL ANALYSIS     C. Si. Mn Ni. Cr. Mo. 0.40% 0.30% 0.60% 1.50% 1.20% 0.25% Hardening: Heat uniformly to 823/850°C until heated through. Quench in oil. Tempering: Heat uniformly and thoroughly at the selected tempering temperature, up to 660°C and hold at heat for two hours per inch of total thickness. Tempering between 250-375°C in not recommended as this can seriously reduce the steels impact value. Stress Relieving: Heat slowly to 650-670°C, soak well before cooling the a furnace or in air.   Heat Treatment Tensile Strength Rm N/mm² Yield Stress Re N/mm² a% on 5.665ÖSo Impact Izod J Impact KCV J Proof Stress rp0.2 Hardness HB Size mm T 850/1000 654 13 40 35 635 248/302 >150≤250 T 850/1000 680 13 54 50 665 248/302 >63≤250 U 925/1075 755 12 47 54 740 269/331 >29≤100 V 1000/1150 850 12 47 42 835 293/352 >13≤63 W 1075/1225 940 11 40 35 925 311/375 >6≤29 X 1150/1300 1020 10 34 28 1005 345/401 >6≤29 Z 1550 1235 5 10 9 1125 444 >6≤29