Resources Hub
ISO 2768 Tolerance Charts
ISO 2768 is divided into two parts. Part 1 (ISO 2768-1) covers general tolerances for linear and angular dimensions, while Part 2 (ISO 2768-2) addresses general geometric tolerances. Values are shown in millimeters (mm).
Part 1: Linear Dimensions
| Permissible deviations in mm for ranges in nominal lengths | Tolerance Class Designation (Description) | |||
|---|---|---|---|---|
| f (fine) | m (medium) | c (coarse) | v (very coarse) | |
| 0.5 up to 3 | ±0.05 | ±0.1 | ±0.2 | -- |
| over 3 up to 6 | ±0.05 | ±0.1 | ±0.3 | ±0.5 |
| over 6 up to 30 | ±0.1 | ±0.2 | ±0.5 | ±1.0 |
| over 30 up to 120 | ±0.15 | ±0.3 | ±0.8 | ±1.5 |
| over 120 up to 400 | ±0.2 | ±0.5 | ±1.2 | ±2.5 |
| over 400 up to 1000 | ±0.3 | ±0.8 | ±2.0 | ±4.0 |
| over 1000 up to 2000 | ±0.5 | ±1.2 | ±3.0 | ±6.0 |
| over 2000 up to 4000 | -- | ±2.0 | ±4.0 | ±8.0 |
External Radii and Chamfer Heights
| Permissible deviations in mm for ranges in nominal lengths | Tolerance Class Designation (Description) | |||
|---|---|---|---|---|
| f (fine) | m (medium) | c (coarse) | v (very coarse) | |
| 0.5 up to 3 | ±0.2 | ±0.2 | ±0.4 | ±0.4 |
| over 3 up to 6 | ±0.5 | ±0.5 | ±1.0 | ±1.0 |
| over 6 | ±1.0 | ±1.0 | ±2.0 | ±2.0 |
Angular Dimensions
| Permissible deviations in mm for ranges in nominal lengths | Tolerance Class Designation (Description) | |||
|---|---|---|---|---|
| f (fine) | m (medium) | c (coarse) | v (very coarse) | |
| up to 10 | ±1° | ±1° | ±1°30' | ±3° |
| over 10 up to 50 | ±0°30' | ±0°30' | ±1° | ±2° |
| over 50 up to 120 | ±0°20' | ±0°20' | ±0°30' | ±1° |
| over 120 up to 400 | ±0°10' | ±0°10' | ±0°20' | ±0°30' |
| over 400 | ±0°5' | ±0°5' | ±0°10' | ±0°20' |
Part 2: General Geometric Tolerances (ISO 2768-2)
ISO 2768-2 specifies general tolerances for geometric features using tolerance classes H, K, and L, with H being the most precise.
Table 4 - General Tolerances on Straightness and Flatness
| Ranges of nominal lengths in mm | Tolerance Class | ||
|---|---|---|---|
| H | K | L | |
| up to 10 | 0.02 | 0.05 | 0.1 |
| above 10 to 30 | 0.05 | 0.1 | 0.2 |
| above 30 to 100 | 0.1 | 0.2 | 0.4 |
| above 100 to 300 | 0.2 | 0.4 | 0.8 |
| above 300 to 1000 | 0.3 | 0.6 | 1.2 |
| above 1000 to 3000 | 0.4 | 0.8 | 1.6 |
Table 5 - General Tolerances on Perpendicularity
| Ranges of nominal lengths in mm | Tolerance Class | ||
|---|---|---|---|
| H | K | L | |
| up to 10 | 0.2 | 0.4 | 0.6 |
| above 10 to 30 | 0.3 | 0.6 | 1.0 |
| above 30 to 100 | 0.4 | 0.8 | 1.5 |
| above 100 to 300 | 0.5 | 1.0 | 2.0 |
Table 6 - General Tolerances on Symmetry
| Ranges of nominal lengths in mm | Tolerance Class | ||
|---|---|---|---|
| H | K | L | |
| up to 10 | 0.5 | 0.6 | 0.6 |
| above 10 to 30 | 0.5 | 0.6 | 1.0 |
| above 30 to 100 | 0.5 | 0.8 | 1.5 |
| above 100 to 300 | 0.5 | 1.0 | 2.0 |
Table 7 - General Tolerances on Circular Run-Out
| Ranges of nominal lengths in mm | Tolerance Class | ||
|---|---|---|---|
| H | K | L | |
| any length | 0.1 | 0.2 | 0.5 |
Tolerance Interpretation
When a dimension is specified with a general tolerance class (e.g., ISO 2768-1 f), the permissible deviation is determined by the dimension's nominal size range. For example, a dimension of 25mm under ISO 2768-1 f would have a permissible deviation of ±0.1mm, as it falls within the 6 to 30mm range.
For angular dimensions, the same principle applies. An angle of 40° under ISO 2768-1 f would have a permissible deviation of ±0°30', as it falls within the 10 to 50° range.
Note that these general tolerances apply only when no specific tolerance is indicated on the drawing. If a dimension has an explicit tolerance, that specific tolerance supersedes the general tolerance.