Thrust ball bearings This type of bearing is separablewhich can only carry axial load. The single direction bearings of them can only carry axial load in one directionwhile the double carry alternating axial load in either direction. Before using they have to be preloaded. The thrust ball bearings are used in lathe centersautomobile clutchesreducers and so on. The double direction angular contact thrust ball bearings are suitable for machine tool spindleswhile the single are used to support ball screws.