Dynamic load rating C

The dynamic load rating C, defined in ISO 281, is the constant load of fixed direction that a rolling bearing can theoretically sustain for a basic rating life of one million revolutions — purely radial for radial bearings, purely axial and centric for thrust bearings. It is calculated by the manufacturer from bearing geometry, material and manufacturing quality and listed in every dimension table.

C is the key input for life calculation: the ratio C/P together with the life exponent (p = 3 for ball bearings, p = 10/3 for roller bearings) yields the basic rating life L10. In practice, C is the primary figure for comparing bearings with identical boundary dimensions.