Mass fraction of elements not more than, %: Carbon (C) 0,33-0,40; Silicon (Si) 0,17-0,37; Manganese (Mn) 0,25-0,5; Chromium (Cr) 1,3-1,7; Nickel (Ni) 1,3-1,7; Molybdenum (Mo) 0,2-0,3; Copper (Cu) up to 0,3; Phosphorus (P) up to 0,025; Sulphur (S) up to 0,025.