ISO 2768 is an international standard intended to simplify drawing indications. It applies to parts that are manufactured by metal removal (machining), sheet metal forming, or casting, where the general tolerances are sufficient without individual inspection.
The standard is divided into two critical parts:
If your drawing block contains a note like "ISO 2768-m" or "General Tolerances ISO 2768-f," the entire part is governed by these rules.
Tolerances in mm for nominal size ranges (up to 3000mm).
| Nominal Size Range | f (Fine) | m (Medium) | c (Coarse) | v (Very Coarse) | | :--- | :--- | :--- | :--- | :--- | | 0.5 up to 3 | ±0.05 | ±0.1 | ±0.2 | — | | >3 up to 6 | ±0.05 | ±0.1 | ±0.3 | ±0.5 | | >6 up to 30 | ±0.1 | ±0.2 | ±0.5 | ±1.0 | | >30 up to 120 | ±0.15 | ±0.3 | ±0.8 | ±1.5 | | >120 up to 400 | ±0.2 | ±0.5 | ±1.2 | ±2.5 | | >400 up to 1000 | ±0.3 | ±0.8 | ±2.0 | ±4.0 | | >1000 up to 2000 | ±0.5 | ±1.2 | ±3.0 | ±6.0 | | >2000 up to 3000 | — | ±2.0 | ±4.0 | ±8.0 |
Expert Tip: For a 100mm shaft (Class "m"), the tolerance is ±0.3mm. If you need tighter than this, you must specify the dimension individually (e.g., 100 +0.02/-0.00).
ISO 2768 is an international standard that defines general tolerances for linear and angular dimensions without individual tolerance indications. It applies to parts that are produced by metal removal or formed from sheet metal. iso 2768 general tolerances pdf exclusive
The standard is split into two critical parts:
If your drawing contains a general note like "ISO 2768-mK," you have invoked this standard.
In the world of mechanical engineering and manufacturing, the devil is in the details—specifically, the microscopic deviations that occur when cutting, milling, or casting a part. If every dimension on a technical drawing required an explicit tolerance, blueprints would be unreadable messes of numbers.
This is where ISO 2768 becomes the unsung hero of the workshop.
For professionals searching for the "iso 2768 general tolerances pdf exclusive," you are likely tired of generic, low-resolution charts or broken links. You need the authoritative standard explained in a way that saves time, reduces scrap rates, and ensures your parts fit on the first try.
This article serves as your exclusive deep dive into ISO 2768. We will cover Part 1 (Linear and Angular tolerances) and Part 2 (Geometrical tolerances), explain how to interpret the tolerance classes (f, m, c, v), and provide guidance on accessing the official documentation. ISO 2768 is an international standard intended to
To activate ISO 2768, you must write a specific note in the drawing’s title block or general notes section.
The Exclusive Syntax:
"ISO 2768-m"
If you need different classes for linear vs. geometrical:
"ISO 2768-1 m / ISO 2768-2 f"
What the note does NOT cover:
Angles are treated specially. For a 90° angle on a large part, a ±0.5° tolerance is massive. ISO 2768-1 uses short side length to determine tolerance.
| Tolerance Class | Short Side Length up to 10mm | 10 to 50mm | 50 to 120mm | 120 to 400mm | >400mm | | :--- | :--- | :--- | :--- | :--- | :--- | | f (Fine) | ±1° | ±0°30' | ±0°20' | ±0°10' | ±0°5' | | m (Medium) | ±1° | ±0°30' | ±0°20' | ±0°10' | ±0°5' | | c (Coarse) | ±1°30' | ±1° | ±0°30' | ±0°15' | ±0°10' | | v (V. Coarse) | ±3° | ±2° | ±1° | ±0°30' | ±0°20' |
Exclusive Pro Tip: Do not use angular tolerance for a 5mm short side on a 2-meter beam. Convert the angular tolerance to linear deviation (arc length = angle in radians × length) to see if it's realistic.
Myth 1: "ISO 2768 applies to any dimension without a tolerance." Truth: No. It only applies to dimensions that are functionally non-critical. If a dimension is critical but you forgot the tolerance, ISO 2768 protects the manufacturer, not the designer. The manufacturer can use "Coarse" by default unless specified.
Myth 2: "The PDF is universal for all materials." Truth: The standard explicitly assumes normal rigidity. For rubber, soft aluminum (1100 series), or thin-walled titanium, the standard’s "Fine" tolerance is impossible to hold without custom fixtures.
Myth 3: "Symmetry tolerance is half the value of flatness." Truth: No. ISO 2768-2 ties symmetry directly to the tolerance grade. Class "m" symmetry = 0.5mm (same as flatness for a 200mm part). If your drawing block contains a note like