| Nominal Angle Range | Tolerance Class 'm' | | :--- | :--- | | Up to 10mm length of shorter side | ±1° | | >10mm up to 50mm | ±0°30' (30 arc minutes) | | >50mm up to 120mm | ±0°20' (20 arc minutes) | | >120mm up to 400mm | ±0°10' (10 arc minutes) | | >400mm | ±0°5' (5 arc minutes) |
Understanding and referencing the ISO 2768-mH tolerance chart is essential for engineers, machinists, and quality control inspectors. It streamlines the drafting process by eliminating the need to assign individual tolerances to every single feature, relying instead on standardized, workshop-friendly ranges. What is ISO 2768?
Do not write just "Tolerances: mH" without referencing ISO 2768. The standard implies specific rules for radii, chamfers, and how to treat zero values. iso 2768-mh tolerance chart
A brief comparative table (conceptual):
The following tables contain the exact values used to inspect and manufacture parts under the ISO 2768-mh standard. All values are listed in millimeters (mm). 1. Linear Dimensions (Class m - Medium) | Nominal Angle Range | Tolerance Class 'm'
The designation "ISO 2768-mh" combines a specific precision level from Part 1 and Part 2. The Meaning of "m" (Medium)
ISO 2768‑1 also provides default angular tolerances (e.g., ±1° for coarse grades, ±0.5° for medium — see the standard for exact figures) and for unspecified radii/chamfers. Do not write just "Tolerances: mH" without referencing
These high-precision limits define the allowed deviation for the form and orientation of a part. Feature Range (mm) Tolerance (mm) Perpendicularity Symmetry Run-out All ranges Key Application Rules