Axial ball bearings are made up of a row of balls guided by a casing and rotating between two rings; both with flat seats. They are built to withstand heavy axial loads operating in one direction but they are not suitable for supporting radial loads.

One feature of the operation of these ball bearings is that they must be subject to a minimal axial load to avoid slips occurring where the balls contact the rolling tracks, due to the centrifugal force generated in the application. Although it must be said that on many occasions, the weight of the machine itself and the external forces supported more than meet this requirement.