| Nominal Size Range | Permissible Deviation (± mm) | |--------------------|-------------------------------| | 0.5 – 3 | ±0.1 | | >3 – 6 | ±0.1 | | >6 – 30 | ±0.2 | | >30 – 120 | ±0.3 | | >120 – 400 | ±0.5 | | >400 – 1000 | ±0.8 | | >1000 – 2000 | ±1.2 |
Refers to Part 2 of the standard, covering Geometrical tolerances (like flatness, symmetry, and run-out). The 'k' is the class for general geometrical tolerances. ISO 2768-1: Linear Dimensions (The 'm') general tolerance iso 2768-mk
| Nominal Length Range | Tolerance (mm) | |----------------------|----------------| | ≤ 100 | 0.2 | | >100 – 300 | 0.3 | | >300 – 1000 | 0.4 | | >1000 – 3000 | 0.5 | | Nominal Size Range | Permissible Deviation (±
Defines geometric tolerances (form and position). The 'K' stands for "K" class (a moderate level of precision). The 'K' stands for "K" class (a moderate level of precision)
This part controls the "form" of the part. For example, "K" ensures a surface stays reasonably flat or straight without needing a specific GD&T callout for every face. The General CNC Machining Tolerance: ISO 2768-mk
Note: For attributes like , Concentricity , and Parallelism , ISO 2768-2 directs users to rely on other fundamental geometric relationships (such as the envelope requirement or total run-out) rather than listing isolated general tolerance brackets. How to Implement ISO 2768-mk Correctly
Angular deviations are measured based on the length of the shorter leg of the angle in question: Nominal Length of Shorter Leg (mm) Permissible Deviation (Degrees & Minutes) over 10 to 50 over 50 to 120 over 120 to 400 2. The "K" Class: Geometrical Tolerances