Used for rough manufacturing processes like forging or casting. How to Read an ISO 286 Tolerance Designation
| Standard | Focus | Relationship to ISO 286 | | :--- | :--- | :--- | | | Limits & Fits for linear sizes | The core standard | | ISO 2768 | General tolerances (no individual inspection) | Complementary (less precise) | | ISO 14405 | Linear size tolerancing (alternative to ±) | Overlapping, newer philosophy | | ANSI/ASME B4.2 | Inch-based limits & fits (US) | Similar logic, different units |
The PDF version of the ISO 286 standard appears to be well-organized and easy to navigate. The document includes:
: Establishes the terminology, symbols, and basic concepts for the ISO code system. iso 286 pdf
ISO 286 is related to other standards, including:
In the ISO system, these terms are used broadly to describe any mating features, whether cylindrical or geometric:
Let’s assume you have printed out an (or saved this page). Here is how to apply it. Used for rough manufacturing processes like forging or
The letter (for holes) and h (for shafts) represent the zero line, where the deviation starts exactly at the nominal size. 4. International Tolerance Grade (IT Grade)
ISO 286 complements:
Understanding ISO 286: The Definitive Guide to the ISO System of Limits and Fits ISO 286 is related to other standards, including:
The hole size is kept constant (usually using the 'H' tolerance zone), and the shaft tolerance is varied to achieve the desired fit. This is the most economically preferred method because standard tools like drills and reamers produce fixed hole sizes, making it cheaper to modify the shaft size on a lathe.
If you absolutely need the official document for an audit or legal compliance, you have to purchase it. Here are the official vendors:
The combination of a hole and a shaft tolerance determines the type of fit, which can be classified into three categories: