1,Chemical composition C: 0.45-0.75% Mn: 0.40-1.20% Si: 0.10-0.30% S less than 0.04% P less than 0.04% 2, Average hardness ( Measured under 500g load ) 1.0mm: 51-53 HRC (525-561HV) 1.5mm: 41-45 HRC (388-436HV) 3, Hardness deviation: The maximum deviation is1.0HRC or 4.0HV 4, Anti-drag intensity 1.0mm: 1750-2150 Mpa 1.5mm: 1250-1450 Mpa 5, Minimum density (determined alcohol displacement): 7.8g/cm3 6, High strength, long lasting Ervin life: Steel cut wire shot: 2800 cycles.