ISO 286 Tolerance Calculator
Compute the fundamental tolerance for a nominal size at a chosen ISO 286 IT grade (IT6 through IT11).
How to Use the ISO 286 Tolerance Calculator
- Enter the nominal size in mm.
- Pick the IT grade from IT6 to IT11.
- Click Calculate.
Casos de Uso
- •Drawing annotation.
- •GD&T training.
- •Selecting fits for shafts and bores.
Fórmula
IT (µm) = k · (0.45 · ∛D + 0.001 · D), where D is nominal diameter in mm and k depends on the IT grade.
Perguntas Frequentes
Which standard defines these values?
ISO 286-1:2010 (formerly ISO/R 286-1 from 1962) specifies the tolerance unit i and the k factors for IT grades 01 through 18.
When should I use IT6 vs IT11?
IT6–IT7 suit precision fits like ball bearings and precision spindles; IT8–IT9 are general machining; IT10–IT11 are for coarse parts and unmachined surfaces.
What about sizes above 500 mm?
The formula changes for sizes above 500 mm. Refer directly to ISO 286-1 tables for large components.