When a drawing specifies "ISO 2768" in its title block, manufacturers instantly know the acceptable limits for every unmarked dimension, angle, and geometric feature. This streamlines communication between design offices and machine shops worldwide. Why Use General Tolerances?
Are you designing for a (like injection molding or CNC milling)? Share public link
The standard applies to dimensions of parts that are produced by metal removal or are formed from sheet metal. These tolerances may also be suitable for use with materials other than metal.
Permissible deviations in millimeters (mm) based on the longer lateral side: Tolerance Class Up to 100mm 100 to 300mm 300 to 1000mm K L Symmetry and Run-out Iso 2768 General Tolerances Pdf
This part of the standard mainly applies to features produced by removal of material and contains tables that define permissible deviations for each geometrical characteristic.
, here is a breakdown of the standard used to simplify technical drawings by providing universal tolerance classes for dimensions without individual indications. 🛠️ What is ISO 2768?
(Note: Values above are approximate summaries; always consult the official PDF for the exact table.) When a drawing specifies "ISO 2768" in its
Selecting the appropriate tolerance class is a critical design decision that balances precision requirements against manufacturing cost and feasibility.
Controls the 90-degree relationship between two surfaces based on the longer of the two sides forming the angle. Tolerance Class Up to 100mm 100 to 300mm 300 to 1000mm 1000 to 3000mm K L Symmetry and Run-out
ISO 2768 is an international standard that defines general tolerance classes for linear and angular dimensions, as well as geometrical features. It is divided into two primary parts: ISO - International Organization for Standardization Part 1 (ISO 2768-1): Are you designing for a (like injection molding
: Class H allows up to 0.1mm, Class K allows up to 0.2mm, and Class L allows up to 0.5mm. How to Read a Drawing Callout
| Nominal Size Range (mm) | 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 | Source: ISO 2768-1
Without a general tolerance reference in the title block, every machine shop interprets untoleranced dimensions differently. Some default to national standards, others guess. ISO 2768 eliminates that ambiguity with a single, globally understood callout.