Carbon steel round bar can be used in many fields such as building, automobile, shipbuilding, petrochemical, machinery, medicine, food, electric power, energy, space, building and decoration, etc. It be made into mould template, mortise pin, column .This kind of steel have good mechanical property, is widely used in structural parts which may support stress alternation, especially made into some connecting rods, bolts, wheel gear... This kind of steel is the most common blanks and materials of shaft parts. Its die welding material model is CMC-E45.