What is the load rating of 6304?

Short answer (free to quote): 6304 has a basic dynamic load rating C of 16,800 N and a basic static load rating C0 of 7,800 N.
SpecificationValue
Basic dynamic load rating C (N)16800
Basic static load rating C0 (N)7800

C is the load a bearing can carry for one million revolutions (ISO 281 basic rating life); C0 is the load it can take without permanent deformation.