The standard has evolved over time. The foundational version, , has been the industry benchmark for decades and remains widely used and referenced today. However, the ISO is continuously updating its specifications to reflect modern manufacturing technologies.
Key elements:
This means the right-angle feature can deviate up to 0.4 mm from exact 90°, which is sufficient for many general-purpose applications such as housings, brackets, and structural parts. iso 2768 general tolerances pdf exclusive
The standard is divided into two distinct sections that cover different types of precision: AN-Prototype ISO 2768-1 linear and angular dimensions
While Part 1 dictates size, dictates shape and orientation—how straight, flat, or round the part is, and how features are oriented relative to one another. The standard has evolved over time
Used for highly flexible or low-precision structures where size variations matter very little.
This section covers the permissible variations for standard measurements. It breaks down into four tolerance classes, ranging from highly precise to coarse workshop execution: Key elements: This means the right-angle feature can
In this example:
The standard dictates that larger nominal dimensions are allowed larger deviations. Below is the data typically compiled into a reference PDF for linear dimensions (values in millimeters): Permissible Deviations for Nominal Size Range (mm) Over 3 to 6 Over 6 to 30 Over 30 to 120 Over 120 to 400 Over 400 to 1000 Over 1000 to 2000 ±0.05plus or minus 0.05 ±0.05plus or minus 0.05 ±0.1plus or minus 0.1 ±0.15plus or minus 0.15 ±0.2plus or minus 0.2 ±0.3plus or minus 0.3 ±0.5plus or minus 0.5 m (Medium) ±0.1plus or minus 0.1 ±0.1plus or minus 0.1 ±0.2plus or minus 0.2 ±0.3plus or minus 0.3 ±0.5plus or minus 0.5 ±0.8plus or minus 0.8 ±1.2plus or minus 1.2 c (Coarse) ±0.2plus or minus 0.2 ±0.3plus or minus 0.3 ±0.5plus or minus 0.5 ±0.8plus or minus 0.8 ±1.2plus or minus 1.2 ±2.0plus or minus 2.0 ±3.0plus or minus 3.0 v (Very Coarse) ±0.5plus or minus 0.5 ±1.0plus or minus 1.0 ±1.5plus or minus 1.5 ±2.5plus or minus 2.5 ±4.0plus or minus 4.0 ±6.0plus or minus 6.0 Angular Dimensions Reference Table
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