Standards reference
ISO 286 — Limits, Fits and Tolerance Classes
DraftFit reference page for the ISO 286 tolerance-code system used for linear sizes, tolerance classes and fits.
Reference
ISO 286-1:2010 / ISO 286-2:2010
ISO 286-1:2010 remains current and was confirmed in 2026. Always verify the edition required by your project.
What the standard system covers
ISO 286 defines the code system used to express tolerance classes and fits for linear sizes. Part 1 establishes the basis, terminology and principles of tolerances, deviations and fits; Part 2 provides tables of standard tolerance classes and limit deviations.
How DraftFit uses it
The fit calculator combines a nominal size, hole tolerance zone and shaft tolerance zone to determine limit sizes and the resulting clearance/interference range for the implemented data set.
Calculator
ISO 286 Fit Calculator →This page is an orientation aid, not a reproduction of the standard. Obtain and use the controlled standard required by your project.