The special geometry of angular contact bearing raceways and shoulders creates ball contact angles that support higher axial loads. Different designs offer contact angles ranging from 20° to 40°. Higher angles provide more axial load capacity for longer service life operating under axial and radial loads. 

"Angular contact bearings" are designed such that there is an angle between the races and the balls when the bearing is in operation. An axial load passes in a straight line through the bearing, whereas a radial load takes an oblique path that tends to want to separate the races axially. So the angle of contact on the inner race is the same as that on the outer race. Angular contact bearings are typically assembled with a thrust load or preload. The preload creates a contact angle between the inner race, the ball and the outer race. The preload can be done while manufacturing the bearing or it can be done when the bearing is inserted into an application. 

The contact angle is measured relative to a line running perpendicular to the bearing axis. Angular contact bearings are capable of withstanding heavy thrust loads and moderate radial loads. The larger the contact angle (typically in the range 10 to 45 degrees), the higher the axial load supported, but the lower the radial load. In high speed applications, such as turbines, jet engines, dentistry equipment, the centrifugal forces generated by the balls will change the contact angle at the inner and outer race. 

Angular contact ball bearings are non-separable type bearings and typically used for carrying combined (axial and radial) loads. They can carry pure axial load and operate in higher speed. That's why many people refer to them incorrectly as thrust bearings.There are three basic types of angular contact ball bearings:

• Single Row Bearings

• Double Row Bearing

• Four Point Contact Ball Bearings

Single row angular contact ball bearings can carry axial loads acting in one direction only. Under the radial loads the force acting in the axial direction needs to be countered. It is usually adjusted against the second bearing. These bearings have one high and one low shoulder on each ring allowing more number of balls to be incorporated. 

There are two standard versions of single row angular contact ball bearings used for different purposes. 

The design of double row angular contact ball bearings is similar to two single row angular contact ball bearings placed adjacent. The design is non separable type. The basic design does not have filling slots and can accommodate equal axial loads in both directions. 

Four point contact ball bearings are single row having raceways that enable to accommodate axial loads in both directions. 

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