Mass fraction of elements not more than, %: Carbon (C) 0,65-0,75; Silicon (Si) 0,15-0,35; Manganese (Mn) 0,15-0,40; Chromium (Cr) 3,20-3,80; Molybdenum (Mo) up to 0,20, Vanadium (V) up to 0,15; Nickel (Ni) up to 0,35; Copper (Cu) up to 0,3; Phosphorus (P) up to 0,03; Sulphur (S) up to 0,03.