Limiting axial load, Pd, is the external axial load of a preloaded bearing pair or set that causes loss of contact between the balls and race in preload bearings. This effect may lead to balls skidding against the races and surface damage.This event may not occur as even a light radial load maintains ball/track contact.In applications (such as in some machine tools), where the working axial load is predominantly in one direction, limiting axial load Pd can be increased by using a bearing set with a mixed contact angle (C3/C1). The axially more rigid bearing (C3) withstands the workload and the less rigid (C1) one is the reaction element.

The limiting axial load Pd is calculated as follows: