Full definition
Total clearance between raceways and rolling elements in the radial or axial direction under no load. Normalized ISO groups: C2 (less than normal, tight fits), CN/C0 (normal, general use), C3 (greater, for elevated temperatures or interference fits), C4 and C5 (maximum). ISO 5753 standard. C3 clearance is most commonly specified in electric motors with variable frequency drives. Brands: SKF, NSK, FAG.