Four-point contact ball bearings are radial single row angular contact ball bearings with raceways that are designed to support axial loads in both directions. For a given axial load, a limited radial load can be supported . These bearings take up considerably less axial space than double row bearings .The inner ring is split. This enables a large number of balls to be incorporated in the bearing,giving the bearing its high load carrying capacity. The bearings are separable,the outer ring with ball and cage assembly can be mounted separately from the two inner ring halves.  This type of bearings are mainly used in machine spindle, gearbox, reducer and supercharger,air compressor, all kinds of transmission,etc . If you want to know more about WSBC QJ309 Four Point contact ball bearings , welcome you contact us freely .