Specifying "ISO 2768-m" allows the machinist to use standard, efficient tools rather than specialized, slow, and expensive precision equipment.
Angular tolerances vary based on the nominal length of the shorter side of the angle:
The two parts work seamlessly together:
Conventional CNC milling and turning naturally fall within the mK bracket. Sheet metal bending or sand casting usually requires cL or v . iso 2768 general tolerances pdf exclusive
Key elements:
The standard is divided into two distinct parts that work together to define a part's precision level: Part Focus Area Tolerance Classes Key Controlled Features Linear & Angular f (fine), m (medium), c (coarse), v (very coarse) Lengths, diameters, radii, chamfer heights, angles. Part 2 Geometrical
| Nominal Length Range (mm) | f (Fine) | m (Medium) | c (Coarse) | v (Very Coarse) | | :--- | :--- | :--- | :--- | :--- | | Up to 10 | 0.02 | 0.05 | 0.1 | 0.2 | | >10 to 30 | 0.05 | 0.1 | 0.2 | 0.4 | | >30 to 100 | 0.1 | 0.2 | 0.4 | 0.8 | | >100 to 300 | 0.2 | 0.5 | 1.0 | 2.0 | | >300 to 1000 | 0.3 | 0.8 | 1.5 | 3.0 | | >1000 to 3000 | 0.4 | 1.0 | 2.0 | 4.0 | Specifying "ISO 2768-m" allows the machinist to use
Angular deviations are measured based on the length of the shorter leg of the angle. Length of Shorter Leg (mm) Medium (m) Coarse (c) Very Coarse (v) Over 10 to 50 Over 50 to 120 Over 120 to 400 Over 400 ISO 2768-2: Geometrical Tolerances
Create a specialized checklist for applying these tolerances to specific manufacturing methods (e.g., CNC milling vs. laser cutting).
The standard defines four tolerance classes: Key elements: The standard is divided into two
| Nominal Length 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 |
Blueprints are easier to read without repetitive +/−positive / minus values on every line.