ISO 2768 (full title: ISO 2768: General Tolerances) is an international standard that specifies general tolerances for linear and angular dimensions without individual tolerance indications on technical drawings.
It applies when a designer does not write a specific tolerance next to a dimension. Instead, the drawing notes "ISO 2768" or "General tolerances ISO 2768-mK" (or similar) in the title block.
The ISO 2768 General Tolerances PDF is more than just a document; it is the silent language of precision engineering. It tells your machinist exactly how much error is acceptable without forcing you to label every single line on your blueprint.
Remember the golden rule: Select the loosest possible tolerance that still allows the part to function. This saves time, money, and material. For 90% of standard machine shop work, ISO 2768-mK (Medium for size, Standard for geometry) is the perfect default. Iso 2768 General Tolerances Pdf
"ISO 2768 Tolerance Class & Value Lookup Engine"
Angular tolerances apply to angles expressed in degrees, minutes, and seconds. The tolerance depends on the length of the shorter side of the angle.
| Length of Shorter Side | Class f / m | Class c / v | | :--- | :--- | :--- | | Up to 10 | ±1° | ±1°30' | | Over 10 up to 50 | ±0°30' | ±1° | | Over 50 up to 120 | ±0°20' | ±0°30' | | Over 120 up to 400 | ±0°10' | ±0°20' | | Over 400 | ±0°5' | ±0°10' | ISO 2768 (full title: ISO 2768: General Tolerances
Having a PDF version of this standard on your desktop or tablet is essential for three reasons:
Rating: 4.7/5
Verdict: Essential for any engineering or manufacturing setting, but make sure you are downloading the correct part (Part 1 for linear/angular vs. Part 2 for geometric). Having a PDF version of this standard on
While Part 1 covers size, Part 2 covers form and position. This is where the "H", "K", "L" tolerance grades appear. (Note: For geometrical tolerances, the classes are H, K, and L).
| Grade | Description | | :--- | :--- | | H | Precision (finest) | | K | Medium (general) | | L | Coarse (rough) |