Precision angular contact ball bearings are non-separable and are essentially single row angular contact ball bearings. In all such bearings the load is transmitted from one raceway to another at an angular to the bearing axis. These bearings can therefore carry axial loads acting in one direction in addition to radial loads. Axial forces produced in the bearing when subjected to a radial load must be counteracted by an opposing force applied externally. The bearings are therefore adjusted against a second bearing.