When the single-row angular contact ball bearing is carrying the radial load, they will be a component of force in the axial direction. Therefore it is suggested that two of there bearings be applied in back-to-back or face-to-face arrangements. Single row bearings can carry radial load and axial load in one direction. Double-row angular contact ball bearings have two designs of one outer ring and two inner rings and one outer ring and one inner ring. For the design with one outer ring and two inner rings, the axial clearance is easy to control during machining.