Sources and scope for this page: Industry convention — no single governing standard (conventional usage, definitions vary between sources), covering the definition of basic dynamic load rating (c). No independent source check is recorded for this page: the content rests on the sources listed and on the working shown on the page. How sources, methods and updates are recorded.
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.