Simplified linear tolerance table (mm):

ISO 2768-mK is an international manufacturing standard used to simplify technical drawings by providing a "default" set of tolerances for features that do not have specific values written next to them. This callout ensures that every part of a drawing is controlled without the need to clutter it with repetitive data, balancing precision with manufacturing efficiency. Understanding the "mK" Notation

| Nominal Length Range (mm) | Class f (Fine) | Class m (Medium) | Class c (Coarse) | Class v (Very Coarse) | | :--- | :---: | :---: | :---: | :---: | | | ±0.05 | ±0.10 | ±0.20 | — | | 3 up to 6 | ±0.05 | ±0.10 | ±0.30 | ±0.50 | | 6 up to 30 | ±0.10 | ±0.20 | ±0.50 | ±1.00 | | 30 up to 120 | ±0.15 | ±0.30 | ±0.80 | ±1.50 | | 120 up to 400 | ±0.20 | ±0.50 | ±1.20 | ±2.50 | | 400 up to 1000 | ±0.30 | ±0.80 | ±2.00 | ±4.00 | | 1000 up to 2000 | ±0.50 | ±1.20 | ±3.00 | ±6.00 | | 2000 up to 4000 | — | ±2.00 | ±4.00 | ±8.00 |

ISO 2768 was originally designed primarily for metal-removal machining operations . If you are manufacturing parts via plastic injection molding, 3D printing, or sheet metal bending, standard CNC tolerances like "m" might be too tight or inappropriate. Other standards (like ISO 20457 for plastics) are better suited for those processes.