| Nominal Length of Shorter Side (mm) | Permissible Deviation (mm/m or degrees) | | :--- | :--- | | Up to 10 | ±1° | | >10 up to 50 | ±0°30' | | >50 up to 120 | ±0°20' | | >120 up to 400 | ±0°10' | | >400 | ±0°5' |
| Feature | Requirement | Tolerance Class | Permissible Limit | | :--- | :--- | :--- | :--- | | | Linear Dimension | ISO 2768-m | 49.7 mm to 50.3 mm (Range 30-120, ±0.3) | | Length | Linear Dimension | ISO 2768-m | 199.5 mm to 200.5 mm (Range 120-400, ±0.5) | | Surface Flatness | Geometric | ISO 2768-K | Max deviation 0.4 mm (Range 100-300) | | End Perpendicularity | Geometric | ISO 2768-K | Max deviation 0.6 mm (Range 100-300) | general tolerance iso 2768-mk
| Standard | Class | Precision Level | Typical Application | | --- | --- | --- | --- | | ISO 2768-fH | Fine / High | Very tight | Precision instruments, aerospace | | | Medium / Medium | Balanced | General machining, automotive, industrial equipment | | ISO 2768-cL | Coarse / Low | Loose | Welded assemblies, rough castings | | Nominal Length of Shorter Side (mm) |