Four-point contact ball bearings are radial single row angular contact ball bearings with raceways that are designed to support axial loads acting in both directions. Radial loads can be supported up to a certain fraction of the axial load. These bearings take up considerably less axial space than double row bearings.

Four-point contact ball bearings of the QJ design (fig1) have a contact angle of either 35° or 45°. The inner ring is split. This enables a large number of balls to be incorporated in the bearing thus giving the bearing high load carrying capacity. The bearings are of separable design, i.e. the outer ring with ball and cage assembly can be mounted separately from the two inner ring halves.

Both inner ring halves of four-point contact ball bearings have a recessed shoulder (fig2). This improves the oil flow when the bearing is used together with an Horton cylindrical roller bearing (fig3). In addition, these recesses can be used to facilitate dismounting.