Thin section bearings are bearings with very small ring cross-section that can be used to save on design envelope and mass, as the name implies, the inside and outside diameters of the rings have been minimized. These thin section ball bearings are available as deep groove ball bearings, angular contact ball bearings, four point contact ball bearings and crossed roller bearing, and can be divided into different types according the working condition, such as open type bearings, shield type bearings, and sealed type bearings, they are also called slim ball bearings, thin type bearings, thin bearing, thin wall bearings.