This type of bearings is separable,which can only carry axial load. the single direction bearings of them can only carry axial load in one direction,while the double can carry alternating axial load in either direction.befor using they have to be preloaded,the thrust ball bearings are used in lathe centers,automobile clutches,redu-cers and so on.the double diretion angula contact thrust ball bearings are suitable for machine tool spindles,while the single are used to support ball screws.