ZIKO 
General Tolerances ISO 2768
Permissible deviations for linear and angular dimensions and tolerances for form and position – for all dimensions without an individual tolerance.
Permissible deviations for linear and angular dimensions and tolerances for form and position – for all dimensions without an individual tolerance.
Many drawings state “ISO 2768-mK” in the title block. This indication defines the tolerances that apply to all dimensions and features without an individual tolerance. Enter a nominal size and the tolerance classes – the calculator shows the permissible deviations for lengths, radii, chamfers and angles to ISO 2768-1 and the general geometrical tolerances for form and position to ISO 2768-2. The matching values are highlighted in the standard tables further down.
Status of the standard: ISO 2768-2 (form and position) was withdrawn in 2021 and replaced by ISO 22081, but it is still found on a great many drawings. The calculator uses the values of ISO 2768-1:1989 and ISO 2768-2:1989. What this means for existing drawings →
Disclaimer: The values have been carefully taken from ISO 2768-1 and ISO 2768-2 and checked against published standard tables, but without guarantee. They are for orientation only and replace neither the standard nor the specifications on the drawing. Use is at your own risk; liability is excluded unless it is based on intent or gross negligence or concerns injury to life, body or health.
Linear and angular
Form and position
All values in millimetres or degrees and minutes of arc. ISO 2768-2 specifies no general tolerances for cylindricity, profile of a line or surface, angularity, position and total run-out. The page address contains the nominal size and classes and can be shared as a link.
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general tolerances – such as circularity, run-out, straightness, diameters or contours – we
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Request an inspection to ISO 2768 →
Permissible deviations and tolerances in millimetres. The values matching the calculator are highlighted.
Linear dimensions except broken edges
e.g. external, internal, step and distance dimensions, diameters, radii
| Nominal size | ffine | mmedium | ccoarse | vvery coarse |
|---|---|---|---|---|
| 0.5 to 3 | ±0.05 | ±0.1 | ±0.2 | – |
| over 3 to 6 | ±0.05 | ±0.1 | ±0.3 | ±0.5 |
| over 6 to 30 | ±0.1 | ±0.2 | ±0.5 | ±1 |
| over 30 to 120 | ±0.15 | ±0.3 | ±0.8 | ±1.5 |
| over 120 to 400 | ±0.2 | ±0.5 | ±1.2 | ±2.5 |
| over 400 to 1000 | ±0.3 | ±0.8 | ±2 | ±4 |
| over 1000 to 2000 | ±0.5 | ±1.2 | ±3 | ±6 |
| over 2000 to 4000 | – | ±2 | ±4 | ±8 |
For nominal sizes below 0.5 mm, the deviations shall be indicated next to the nominal size.
Broken edges
External radii and chamfer heights
| Nominal size | f, m | c, v |
|---|---|---|
| 0.5 to 3 | ±0.2 | ±0.4 |
| over 3 to 6 | ±0.5 | ±1 |
| over 6 | ±1 | ±2 |
Angular dimensions
by length of the shorter side
| Shorter side | f, m | c | v |
|---|---|---|---|
| up to 10 | ±1° | ±1°30′ | ±3° |
| over 10 to 50 | ±0°30′ | ±1° | ±2° |
| over 50 to 120 | ±0°20′ | ±0°30′ | ±1° |
| over 120 to 400 | ±0°10′ | ±0°15′ | ±0°30′ |
| over 400 | ±0°5′ | ±0°10′ | ±0°20′ |
Straightness and flatness
length of the line or longer side of the surface
| Nominal length | H | K | L |
|---|---|---|---|
| up to 10 | 0.02 | 0.05 | 0.1 |
| over 10 to 30 | 0.05 | 0.1 | 0.2 |
| over 30 to 100 | 0.1 | 0.2 | 0.4 |
| over 100 to 300 | 0.2 | 0.4 | 0.8 |
| over 300 to 1000 | 0.3 | 0.6 | 1.2 |
| over 1000 to 3000 | 0.4 | 0.8 | 1.6 |
Perpendicularity
by length of the shorter side
| Shorter side | H | K | L |
|---|---|---|---|
| up to 100 | 0.2 | 0.4 | 0.6 |
| over 100 to 300 | 0.3 | 0.6 | 1 |
| over 300 to 1000 | 0.4 | 0.8 | 1.5 |
| over 1000 to 3000 | 0.5 | 1 | 2 |
Symmetry
by length of the shorter feature
| Nominal length | H | K | L |
|---|---|---|---|
| up to 100 | 0.5 | 0.6 | 0.6 |
| over 100 to 300 | 0.5 | 0.6 | 1 |
| over 300 to 1000 | 0.5 | 0.8 | 1.5 |
| over 1000 to 3000 | 0.5 | 1 | 2 |
Run-out
radial and axial circular run-out, independent of the nominal size
| Characteristic | H | K | L |
|---|---|---|---|
| Radial and axial run-out | 0.1 | 0.2 | 0.5 |
Circularity: equal to the diameter tolerance, but no greater than the run-out tolerance. Parallelism: equal to the size tolerance or the straightness or flatness tolerance, whichever is greater. Coaxiality: not specified, in an extreme case up to the run-out tolerance.
The general tolerances apply when the drawing refers to the standard in or near the title block. The indication consists of the standard number and the tolerance classes:
The classes f (fine), m (medium), c (coarse) and v (very coarse) in part 1 and H, K and L in part 2 are meant to reflect customary workshop accuracy. Where the function requires tighter tolerances or permits larger ones, these are indicated directly at the dimension and take precedence. Part 1 applies to parts produced by metal removal or formed from sheet metal, part 2 mainly to features produced by metal removal. For other processes it has to be checked whether the customary manufacturing accuracy lies within these values; castings have their own standard, ISO 8062.
Part 1 does not apply to auxiliary dimensions in brackets, to theoretically exact dimensions in frames or to nominal sizes below 0.5 mm. Part 2 specifies no general tolerances for cylindricity, profile of a line or surface, angularity, coaxiality, position and total run-out. Right angles that are not dimensioned fall under the angular tolerances of part 1 – if the drawing also refers to part 2, the perpendicularity tolerance applies to them instead.
Both parts of the standard provide that, unless otherwise stated, a workpiece exceeding the general tolerance does not lead to automatic rejection as long as its function is not impaired. If every deviation is to lead to rejection, this has to be agreed separately.
As of September 2026:
Standards apply because contracting parties agree on them – and a withdrawn standard can still be agreed. Countless existing drawings refer to ISO 2768-mK, and many companies continue to work with it. There is no simple conversion to ISO 22081, because the two standards are structured in fundamentally different ways.
The risk lies in the detail: a reference without a year of publication is usually understood as a reference to the current edition – and for part 2, that is now ISO 22081. For existing drawings, it is therefore advisable to add the year, i.e. “ISO 2768-2:1989” instead of “ISO 2768-2”, and to state in orders which edition applies. Once the revised ISO 2768 has been published, the same applies to ISO 2768-1:1989.
The background to the revision: in today's system of Geometrical Product Specifications (GPS), plus/minus tolerances are only unambiguous for sizes, such as a diameter or the width of a slot. Distances between surfaces as well as form and position are specified there with geometrical tolerances. This is why the title of the new ISO 2768 only refers to sizes.
The calculator and the tables on this page reproduce the values of ISO 2768-1:1989 and of the withdrawn ISO 2768-2:1989. They are intended for drawings that refer to these standards. For drawings to ISO 22081, the values given there apply. Fits with ISO tolerance classes such as H7/g6 are calculated by our tolerance calculator.