the object of the invention is to provide a rack shaft having two rack teeth groups and hollowed throughout the whole body , to lightweightize the shaft and to reduce the cost . the two rack teeth groups are located longitudinally apart from each other and have phase difference related to an angle around the axis of the shaft . after the two rack teeth groups are formed simultaneously or sequentially by die forming on the flat bottoms of the workpiece beforehand gutter - shaped , the legs of the gutter - shaped workpiece are bent to butt to each other and , thereby , a tubular body of the shaft is given to the workpiece . the centers of the material are offset beforehand corresponding to the phase difference .