± 3° (for lengths up to 10mm) to ± 1° (over 400mm) Part 2: ISO 2768-2 (Geometrical Tolerances)
"The main difference between ISO 2768 and ISO 286 is that ISO 2768 covers general tolerances for linear and angular dimensions, while ISO 286 covers tolerances for cylinders and opposite parallel surfaces — for example, for shaft and hole systems."
These values limit the bowing or surface warping of a face or axis across its longest nominal length. Tolerance Class Up to 10mm 10 to 30mm 30 to 100mm 100 to 300mm 300 to 1000mm 1000 to 3000mm K L 2. Perpendicularity
To ensure your engineering team has the necessary data at their fingertips, we have provided an exclusive, concise PDF guide detailing both Part 1 and Part 2 of the standard. iso 2768 general tolerances pdf exclusive
Used for rough manufacturing, such as structural steelwork. ISO 2768-1 Linear Dimension Tolerances (mm)
After production, you measure several shafts and get diameters of 52.5 mm, 47.8 mm, 50.2 mm, and 49.9 mm. Which are acceptable?
One common mistake is assuming ISO 2768 applies to every single feature. It is important to remember that:Specific Trumps General: If a specific tolerance is written next to a dimension, that value overrides ISO 2768.Not for Plastics: ISO 2768 was originally designed for metal removal (machining) and sheet metal parts. For plastic injection molding, standards like ISO 20457 are often more appropriate.Check Your Material: Different materials react differently to heat and stress. Ensure the chosen tolerance class is achievable for the material you are using. Conclusion ± 3° (for lengths up to 10mm) to
| Nominal Size Range (mm) | Fine (f) | Medium (m) | Coarse (c) | Very Coarse (v) | |------------------------:|:--------:|:----------:|:----------:|:---------------:| | 0.5 – 3 | ±0.05 | ±0.1 | ±0.2 | — | | >3 – 6 | ±0.05 | ±0.1 | ±0.3 | ±0.5 | | >6 – 30 | ±0.1 | ±0.2 | ±0.5 | ±1.0 | | >30 – 120 | ±0.15 | ±0.3 | ±0.8 | ±1.5 | | >120 – 400 | ±0.2 | ±0.5 | ±1.2 | ±2.5 | | >400 – 1000 | ±0.3 | ±0.8 | ±2.0 | ±4.0 | | >1000 – 2000 | ±0.5 | ±1.2 | ±3.0 | ±6.0 | | >2000 – 4000 | — | ±2.0 | ±4.0 | ±8.0 |
To legally bind your manufacturing partner to these general tolerances, the standard must be explicitly designated in or near the title block of the engineering drawing. The notation combines the rules of both Part 1 and Part 2. ISO 2768 - [Part 1 Class][Part 2 Class] Example 1: ISO 2768-mK This is the most common industry standard designation.
(Using class m as an example)
This part focuses on defining permissible deviations for standard measurements without specific tolerance notes. skolarium.com Application
ISO 2768 is an international standard that provides general geometric and linear tolerances for machined components. It is split into two primary parts: (Linear and Angular Dimensions) and ISO 2768-2 (Geometrical Tolerances).
While Part 1 deals with the size of features, Part 2 addresses the form and position of features (Geometrical Dimensioning and Tolerancing, or GD&T). This section covers tolerances for: Used for rough manufacturing, such as structural steelwork