Based on load characteristics, thrust ball bearings are classified into unidirectional and bidirectional thrust ball bearings. Unidirectional thrust ball bearings can withstand unidirectional axial loads. Bidirectional thrust ball bearings, in which the shaft washers are mated to the shaft, can withstand bidirectional axial loads. Bearings with spherical mounting surfaces on the seat washers offer self-aligning properties, minimizing the impact of installation errors. Thrust ball bearings cannot withstand radial loads and have a lower maximum speed.