Deep groove ball bearing is the most commonly used rolling bearing. Its structure is simple, and it can be easy to operate. They are mainly used for standing the radial load. But when the radial play is increasing, they have the performance of angular contact bearing assembly. In that case, they may simultaneously stand the radial loads and the axial loads. In some cases, which are not suitable to using spherical roller thrust bearing and the rotational speed is rather high. They can also be used to stand purely axial loads. Compared with other kind of bearings with the same size, this kind of bearing enjoys smaller coefficient of friction and higher limits speed. But they cannot bear impact. Therefore, they are not suitable to bear heavy load.