ISO 286 Tolerance and Fit Calculator
Calculate hole and shaft limits for ISO 286 fits such as H7/g6, H7/h6, H7/k6 and H7/p6, with minimum and maximum clearance or interference. Nominal sizes up to 500 mm.
| Upper deviation | Lower deviation | Max size | Min size | |
|---|---|---|---|---|
| Hole | ||||
| Shaft |
Values from ISO 286-1 standard tolerance grades and fundamental deviations for nominal sizes up to 500 mm (k shown for grades IT4–IT7). Check critical fits against the ISO 286-2 tables before production.
Common hole-basis fits
- H7/g6 — sliding fit for precise guiding, e.g. pins and spigots that must move.
- H7/h6 — locational clearance fit; parts assemble by hand.
- H7/k6 — transition fit for accurate location, e.g. hubs and couplings.
- H7/p6 — light press fit for parts that must not move, e.g. bushings pressed into housings.
The hole basis system keeps the hole at H (lower deviation zero) and changes the shaft letter to get the fit you need, because holes are made with standard reamers and gauges.
FAQ
What does H7/g6 mean?
H7 is the hole tolerance (lower deviation 0, width IT7) and g6 is the shaft tolerance (fundamental deviation g, width IT6). Together they give a close sliding fit.
Which fit should I use for a bearing seat?
It depends on the bearing type and load. Bearing manufacturers publish recommended shaft and housing fits; follow those for bearing seats.