[Tolerances] ISO 7919

ISO 7919 is an international standard that specifies tolerances and precision classes for rolling bearings, particularly for bore diameters, outer diameters, and widths. It provides a system for tolerances to ensure interchangeability and proper fit between bearing components and mating parts.

Key aspects of ISO 7919 tolerances include:

• Tolerance Classes: The standard defines various tolerance classes such as P0, P6, P5, P4, P2, etc., with P0 being the normal tolerance and the others representing progressively tighter tolerances.

• Application: These tolerances are used during the manufacturing process to specify allowable deviations from nominal dimensions for bearing parts.

• Dimensional Tolerance System: The tolerances are expressed as limits around the nominal size, often in micrometers, to control the precision of bearing components.

For example:

Tolerance Class	Description	Typical Use
P0	Normal tolerance	General applications
P6	Slightly tighter tolerance	Precise but not critical fits
P5	Higher precision	High-performance applications
P4	Very tight tolerance	Precision machinery

Note: For detailed dimensional tolerances and specific values, consult the ISO 7919 standard document directly, as it provides comprehensive tables with permissible deviations for various sizes and classes.