General Tolerance Iso 2768-mk Jun 2026

It prevents drawings from becoming cluttered with hundreds of individual tolerance notes, making them much easier to read.

By referencing "ISO 2768-mK" in the title block of a technical drawing, engineers apply a blanket set of standardized permissible variations to every dimension that does not have an explicitly stated custom tolerance. Decoding the Components of ISO 2768-mK

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ISO 2768-mk is the "Goldilocks" of manufacturing tolerances—not too tight, not too loose. It ensures that parts are functional and interchangeable without unnecessary manufacturing expenses. When you see it on a drawing, you’re looking at a standard of and Medium Geometrical control . general tolerance iso 2768-mk

By mastering the specific limits of the "m" and "K" classes, engineering teams can optimize their workflows, lower manufacturing costs, and ensure consistent quality across global supply chains.

Do you use ISO 2768-mk on your drawings? Have you ever had a part fail because the general tolerance was too loose? Let us know in the comments below.

These values are selected based on the length of the corresponding line or the larger surface dimension: Nominal Length Range (mm) Tolerance Class Up to 10 Over 10 to 30 Over 30 to 100 Over 100 to 300 Over 300 to 1000 Over 1000 to 3000 Perpendicularity It prevents drawings from becoming cluttered with hundreds

| Standard | Description & Application | | :--- | :--- | | | The 'f' (fine) class for linear dimensions and 'H' class for geometry is significantly tighter than the mK combination. It is the standard choice for most CNC-machined metal parts, especially where precise mating features are critical. For example, for a dimension between 30 and 120 mm, ISO 2768-f would specify a tolerance of ±0.15 mm, while ISO 2768-m allows ±0.3 mm. | | ASME Y14.5 | This is the primary Geometric Dimensioning and Tolerancing (GD&T) standard in the United States. Unlike ISO 2768, which sets default general tolerances, ASME Y14.5 is a comprehensive system using a library of symbols to define specific geometric controls on a feature-by-feature basis. For parts being manufactured to US standards, ASME Y14.5 is the relevant framework. |

You cannot combine classes from different parts arbitrarily in a single shorthand. For example, "ISO 2768-mL" would mean linear class 'm' and geometric class 'L', which is unusual. Always use 'mk' for standard work.

Symmetry ensures that two features on a part are evenly spaced relative to a central datum plane or axis. Under class K, symmetry is tied to the longest feature: Nominal Length Range (mm) Symmetry Tolerance (mm) over 100 to 300 over 300 to 1000 over 1000 to 3000 Run-Out (Circular Run-out) This link or copies made by others cannot be deleted

The designation consists of two distinct parts:

| Feature | Permissible Deviation (mm) | | :--- | :--- | | Run-out (all nominal sizes) | 0.2 |

| Nominal Size Range | Permissible Deviation (± mm) | |--------------------|-------------------------------| | 0.5 – 3 | ±0.2 | | >3 – 6 | ±0.5 |

October 26, 2023 Subject: Application and Interpretation of ISO 2768-mK