| Type | Condition | Tolerance | | :--- | :--- | :--- | | Linear (0.5-6mm) | Size | ±0.1mm | | Linear (6-30mm) | Size | ±0.2mm | | Linear (30-120mm) | Size | ±0.3mm | | Linear (120-400mm) | Size | ±0.5mm | | Flatness | Form | 0.2mm per 100mm | | Straightness | Form | 0.2mm per 100mm | | Perpendicularity | Orientation | 0.3mm per 100mm | | Symmetry | Location | 0.5mm | | Circular Runout | Runout | 0.2mm | | Angle (<10mm leg) | Angle | ±1° | The ISO 2768-mh tolerance chart is the silent workhorse of modern mechanical drawings. By adopting "m" for linear and "H" for geometric tolerances, you strike an optimal balance between manufacturing cost and functional reliability.
| Dimension Range for Radii/Chamfer (mm) | Tolerance Class 'm' (mm) | | :--- | :--- | | 0.5 up to 3 | ±0.2 | | >3 up to 6 | ±0.5 | | >6 up to 30 | ±1.0 | iso 2768-mh tolerance chart
Among the four tolerance classes (f – fine, m – medium, c – coarse, v – very coarse), one stands out as the undisputed king of job shops, prototype development, and general machinery: . | Type | Condition | Tolerance | |