CADSeekho · Reference chart

ISO Fits & Tolerances — Hole-Basis System

Choose a preferred fit or build your own (e.g. H7/g6). Get the hole and shaft limits, maximum and minimum clearance, and see the tolerance zones to scale.

Inputs

Preferred fits

Or build your own

Capital letters = hole, small letters = shaft. In the hole-basis system the hole is usually H (lower deviation = 0).

Results

Tolerance zone diagram (µm, to scale)

Hole zoneShaft zoneZero line = nominal size

How the limits are found — step by step PRO

Preferred hole-basis fits — where to use them

FitTypeTypical use

Data: ISO 286-1 / ISO 286-2 standard tolerance grades and fundamental deviations, nominal sizes up to 120 mm. Always confirm critical tolerances against the current standard (IS 919 is the Indian equivalent).