by increasing the contact area of the ball bearings on the shaft to approximately 45 degrees, the side load and direct load carrying capabilities are greatly increased. each nut can be individually preloaded at the factory to decrease the available radial play to ensure rigidity. this process not only increases the contact area, increasing direct loading capabilities, but it also restricts any radial movement, increasing the overhung moment capabilities. this creates a sturdier structure that can handle a very strenuous working environment.