A high carbon steel wire material which is made of high carbon steel as a raw material for wire products such as steel cords, bead wires, PC steel wires and spring steel, allows for these wire products to be manufactured efficiently at a high wire drawing rate and has excellent wire drawability and a manufacturing process thereof.
This high carbon steel wire material is made of a steel material having specific contents of C, Si, Mn, P, S, N, Al and O, and the Bcc-Fe crystal grains of its metal structure have an average crystal grain diameter (Dave) of 20 μm or less and a maximum crystal grain diameter (Dmax) of 120 μm or less, preferably an area ratio of crystal grains having a diameter of 80 μm or more of 40% or less, an average sub grain diameter (dave) of 10 μm or less, a maximum sub grain diameter (dmax) of 50 μm or less and a (Dave/dave) ratio of the average crystal grain diameter (Dave) to the average sub grain diameter (dave) of 4.5 or less.