General - Tolerance Iso 2768-mk 2021

Tolerances for straightness and flatness are selected based on the length of the corresponding line or the larger surface dimension. Perpendicularity

The standard defines four tolerance grades:

These values are selected based on the length of the longest nominal line or surface. Nominal Length Range ( Tolerance Limit for Class "K" ( 2. Perpendicularity

Linear dimensions encompass lengths, widths, heights, radii, and diameters. The allowable deviation depends entirely on the nominal size of the dimension. general tolerance iso 2768-mk

These apply to nominal sizes like external sizes, internal sizes, steps, diameters, and distances. Nominal Size Range (mm) Tolerance Deviation (mm) for Class "m" ±plus or minus Over 3 to 6 ±plus or minus Over 6 to 30 ±plus or minus Over 30 to 120 ±plus or minus Over 120 to 400 ±plus or minus Over 400 to 1000 ±plus or minus Over 1000 to 2000 ±plus or minus Over 2000 to 4000 ±plus or minus

| Nominal Dimension Range (mm) | Tolerance (mm) | | --- | --- | | 0.5 up to 3 | ±0.1 | | >3 up to 6 | ±0.1 | | >6 up to 30 | ±0.2 | | >30 up to 120 | ±0.3 | | >120 up to 400 | ±0.5 | | >400 up to 1000 | ±0.8 | | >1000 up to 2000 | ±1.2 |

The designation sets specific limits on how much a feature can deviate in shape or position. This section defines tolerances for straightness, flatness, perpendicularity, and symmetry. It also includes a specific rule regarding run-out. Tolerances for straightness and flatness are selected based

| Shorter Leg Length (mm) | Tolerance Class H | Tolerance Class K | Tolerance Class L | | :--- | :---: | :---: | :---: | | | 0.20 | 0.40 | 0.60 | | 100 up to 300 | 0.30 | 0.60 | 0.80 | | 300 up to 1000 | 0.40 | 0.80 | 1.00 | | 1000 up to 3000 | 0.50 | 1.00 | 1.20 |

Therefore, indicates that a component must meet Medium linear tolerances and Medium geometrical tolerances . ISO 2768-m Linear Tolerances (Part 1)

The standard defines specific permissible variations for linear, angular, and geometrical dimensions in machined parts without individual tolerance indications. This designation combines the "m" class (medium) for linear and angular dimensions with the "K" class for geometrical tolerances (form and position). It simplifies engineering drawings, reduces manufacturing costs, and ensures global consistency. Understanding ISO 2768-mK: The Global Engineering Standard Nominal Size Range (mm) Tolerance Deviation (mm) for

O-ring grooves and sealing surfaces require incredibly tight control over depth and surface finish to prevent leaks.

If your assembly has a critical mating part—such as a bearing press-fit or a sealed O-ring groove—the general tolerances of ISO 2768-mk will likely be too loose. In these scenarios, you must (e.g., or a fit callout like

: Machine operators immediately see which dimensions require hyper-precision and which allow standard processing.

Symmetry limits apply to parallel features or slots that share a central datum plane. Nominal Length Range (mm) Symmetry Tolerance (mm) for Class "k" Over 100 to 300 Over 300 to 1000 Over 1000 to 3000 4. Run-Out (Circular Run-Out)

| Shorter Side Length (mm) | Class f (Fine) | Class m (Medium) | Class c (Coarse) | Class v (Very Coarse) | | :--- | :--- | :--- | :--- | :--- | | | ±1° | ±1° | ±1°30′ | ±3° | | 10 up to 50 | ±0°30′ | ±0°30′ | ±1° | ±2° | | 50 up to 120 | ±0°20′ | ±0°20′ | ±0°30′ | ±1° | | 120 up to 400 | ±0°10′ | ±0°10′ | ±0°15′ | ±0°30′ | | > 400 | ±0°5′ | ±0°5′ | ±0°10′ | ±0°20′ |