General Tolerances for Angular Dimensions
Angular dimensions refer to the measurements of angles between different surfaces or edges of a part, for example, a 90° angle. If no specific tolerances are given in the drawing, the general tolerances according to the ISO 2768-1:1989 standard are applied.
The standard defines how much an angle may deviate from its nominal value in different accuracy classes (f, m, c, v). For smaller dimensions, the permitted deviation is larger in degrees, but in practice, the angle remains sufficiently accurate so that parts will fit together properly. For larger dimensions, the permitted angular deviation decreases proportionally, as even a small angular error could cause significant deviations at the ends of the part.
The general tolerances set for angular dimensions make design and manufacturing easier and ensure that parts will fit together correctly without needing to specify a tolerance for every single angle.
General Tolerance Table for Angular Dimensions
| Tolerance Class | Permitted deviations for the shorter side of the angle in the length dimension range (mm) | ||||||
| Symbol | Description | > | 10 | 50 | 120 | 400 | |
| ≤ | 10 | 50 | 120 | 400 | |||
| f | fine | 1° | 0°30´ | 0°20´ | 0°10´ | 0°5´ | |
| m | medium | 1° | 0°30´ | 0°20´ | 0°10´ | 0°5´ | |
| c | coarse | 1°30´ | 1° | 0°30´ | 0°15´ | 0°10´ | |
| v | very coarse | 3° | 2° | 1° | 0°30´ | 0°20´ | |
The values in the table are given in millimeters (mm)
