Engineering Reference

Basic dynamic load rating (C)

The constant load a bearing can carry for one million revolutions of L10 life.

Definition

C is the manufacturer's rating for each bearing, and it varies between makers even when the boundary dimensions are identical — ball complement, raceway geometry and steel quality all affect it.

It is not a maximum load. A bearing loaded above C still runs, just for fewer than a million revolutions, and the L10 formula handles that directly.

Common misuse

Treating the dynamic rating as a load limit. It is a rating constant for a life calculation, not a working load.

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