Full definition
Dimensional correspondence between bearings from different manufacturers sharing the same basic dimensions (bore, outer diameter, width) per ISO 15. Example: SKF 6205 = NSK 6205 = NTN 6205 = FAG 6205 = Timken 6205. Dimensional interchangeability is guaranteed; functional interchangeability depends on equivalent suffixes for sealing, cage and tolerance. Suffixes indicating these features differ between brands (e.g. 2RS1=SKF, DDU=NSK, LLU=NTN). Reference catalogs from NSK, NTN, SKF.