Geometric tolerances ensure features like flatness, straightness, and perpendicularity remain functional without requiring dedicated callouts for every single surface. Straightness and Flatness
(Exact numeric tables are normative content of the ISO standard; consult the standard or licensed reproductions for precise values.)
Angular tolerances scale based on the length of the shorter leg of the angle being measured: Shorter Leg Length Range (mm) Over 10 to 50 Over 50 to 120 Over 120 to 400 ±1∘plus or minus 1 raised to the composed with power m (Medium) ±1∘plus or minus 1 raised to the composed with power c (Coarse) ±1∘plus or minus 1 raised to the composed with power v (Very Coarse) ±3∘plus or minus 3 raised to the composed with power ±2∘plus or minus 2 raised to the composed with power ±1∘plus or minus 1 raised to the composed with power ISO 2768 Part 2: Geometrical Tolerances
Note: For roundness (circularity) and cylindricity, the general tolerance is often derived from the diameter tolerance or other related tolerances. iso 2768 general tolerances pdf exclusive
If a specific feature on that same drawing requires an incredibly tight fit—like a bearing housing—the designer will manually write a tight tolerance (e.g.,
for linear and angular dimensions, as well as geometric features, when no specific tolerance is indicated Overview of ISO 2768 Parts
± 1°30' (for lengths up to 10mm) to ± 0°30' (over 400mm) The standard provides general tolerances for linear and
ISO 2768 is an international standard published by the International Organization for Standardization (ISO). The standard provides general tolerances for linear and angular dimensions, which are applicable to various types of parts and assemblies, including:
For a complete set of tables including angularity and run-out, you can access these technical PDF guides from industry leaders: ISO 2768 Full Guide Dimensional Tolerance Chart Comprehensive Machining PDF DAU Components perpendicularity ISO 2768-2
| Nominal Size Range (mm) | 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 | When formatting a custom reference document, ensure it
: This indicates standard medium tolerances for linear measurements (m) and medium geometric constraints (K). This is the most common specification for general CNC machining.
Designers save hours by only calculating specific tolerances for critical mating features.
When formatting a custom reference document, ensure it contains: The standard linear table (0.5 mm to 2000 mm). The shorter-leg angular deviation limits.
Table 2: General Tolerances for Broken Edges (External Radii and Chamfer Heights) Values are in millimeters (mm). Tolerance Class 0.5 to 3 mm Over 3 to 6 mm m (Medium) c (Coarse) v (Very Coarse) Table 3: General Tolerances for Angular Dimensions