MANUFACTURING METHOD OF LONG SHAFT TYPE WHEEL SHAFT HAVING SIDE TOOTH PROFILE

The present invention relates to a manufacturing method of a long shaft type wheel shaft having a side tooth profile, the method comprising: a material cutting step of cutting a bar-shaped bar into apredetermined length to form a material; a hot forging step including: forming a wheel portion having a predetermined thickness by pressing a portion of the bar with a medium and forming a molding protruding portion protruding upward in the wheel portion and molding a pre-molded article having a side tooth profile, wherein the side tooth profile has gear teeth and tooth grooves repeatedly formed on an outer circumferential surface of the molding protruding portion; a radius forging step of arranging four dies in the circumferential direction on the remaining part of the material, wherein the arranged four dies pressurize the material simultaneously and continuously for molding in four directions of up, down, left and right simultaneously and elongation molding is performed according to a specified length and a pre