The following table provides an overview of the ISO 2768-MH tolerance chart:
Using general tolerances ensures that parts aren't over-engineered with unnecessarily tight (and expensive) limits where they aren't needed . iso 2768-mh tolerance chart
A 5mm chamfer callout with no tolerance is allowed to be 4.5mm to 5.5mm. That is a massive 20% variation. If you need a cosmetic 45° x 1.5mm chamfer, you must explicitly tolerance it as max 1.6mm/ min 1.4mm. The following table provides an overview of the
| Nominal Dimension Range (mm) | Permissible Deviation for Class 'm' (mm) | | :--- | :--- | | 0.5 up to 3 | ± 0.1 | | >3 up to 6 | ± 0.1 | | >6 up to 30 | ± 0.2 | | >30 up to 120 | ± 0.3 | | >120 up to 400 | ± 0.5 | | >400 up to 1000 | ± 0.8 | | >1000 up to 2000 | ± 1.2 | | >2000 up to 4000 | ± 2.0 | If you need a cosmetic 45° x 1
Defines tolerance classes H, K, and L for features.
To legally enforce these guidelines, you must state the standard clearly on the blueprint. This is typically placed inside or directly adjacent to the drawing title block. The standard notation format is: or ISO 2768 - m - h