O-ring grooves and sealing surfaces require incredibly tight control over depth and surface finish to prevent leaks.
If a specific feature requires higher precision than the general 'mK' level, the designer must explicitly label that individual dimension with its own tolerance. Summary of Benefits Cleaner Drawings: Reduces visual clutter by removing common tolerance ranges. Standardization: general tolerance iso 2768-mk
Using ISO 2768-mK is ideal for non-critical features of a part where "standard" workshop accuracy is sufficient. It allows machinists to work faster by focusing only on the dimensions that truly require high precision (e.g., press fits or bearing seats). Common Tolerance Ranges for "mK" O-ring grooves and sealing surfaces require incredibly tight
Simplified linear tolerance table (mm):
While ISO 2768 is the standard in Europe and Asia, you may encounter other systems: you may encounter other systems: