For class m, deviation = ±0.2 mm for nominal sizes 0.5–3 mm, and ±0.5 mm for >3–120 mm. 3.2 Geometrical Tolerances (Part 2 – Class "H") Class H is the fine category for geometrical features such as straightness, flatness, perpendicularity, symmetry, and runout. Table 2 lists permissible deviations for the relevant nominal size ranges of the feature’s longer dimension.
Same values as flatness for the shorter side. iso 2768 m h
For class m, the deviation is ±0.5° or ±30 minutes for nominal lengths ≤120 mm, and ±0°20' per 100 mm length for larger features. For class m, deviation = ±0