Chemical composition: 
 Carbon C: 0.37 ~ 0.45 
 Silicon Si: 0.17 ~ 0.37 
 Mn Mn: 0.70 ~ 1.00 
 Sulfur S: ≤ 0.035 
 Phosphorus P: ≤ 0.035 
 Chromium Cr: ≤ 0.25 
 Ni - Ni: ≤ 0.30 
 Copper Cu: ≤ 0.25 

 Mechanical properties: 
 Tensile strength σb (MPa): ≥ 590 (60) 
 Yield strength σs (MPa): ≥ 355 (36) 
 The elongation δ5 (%): ≥ 17 
 Reduction of area ψ (%): ≥ 45 
 Impact energy Akv (J): ≥ 47 
 The impact toughness αkv (J/cm2): ≥ 59 (6) 
 Hardness: The heat treatment is not ≤ 229HB; annealed steel ≤ 207HB