Iso 2768-mh Tolerance Chart Extra Quality

ISO 2768-mH standard defines general tolerances for parts where specific tolerances aren't individually marked on a drawing. The designation refers to medium dimensional tolerances (Part 1), while refers to high-precision geometrical tolerances (Part 2). Part 1: Dimensional Tolerances (m - Medium)

✅ Example: A 20 mm diameter hole with no tolerance is allowed to be 20.00 mm to 20.33 mm. It can never be 19.98 mm. iso 2768-mh tolerance chart

Summary

• ISO 2768-m: Handles the size (± tolerances).
• ISO 2768-H: Handles the shape (GD&T tolerances).

The "MH" in ISO 2768-MH refers to the specific tolerance class, which is defined as "medium" tolerance. This class provides a balance between the precision required for a part or component and the practical limitations of manufacturing processes. ISO 2768-mH standard defines general tolerances for parts

Scenario 3: Thin Wall (0.8mm thickness)

• Issue: The chart starts at "0.5 up to 3mm" giving a ±0.1mm tolerance.
• Caution: A 0.8mm wall with a ±0.1mm tolerance means the wall could be 0.7mm. That is a 12.5% reduction. ISO 2768-mH is often too loose for thin-walled injection molded parts or delicate sheet metal.

For runout: 0.2 mm (class m).