When to use H7/h6
Minimum clearance zero: assembled by hand, locates well, but not meant to run. Typical for removable fixed spigots, locating bushes, parts that are often taken apart.
H7/h6 tolerances for every diameter
| Diameter (mm) | Hole H7 (µm) | Shaft h6 (µm) | Max clearance | Min clearance |
|---|---|---|---|---|
| ≤ 3 | +10 / 0 | 0 / -6 | +16 | 0 |
| 3–6 | +12 / 0 | 0 / -8 | +20 | 0 |
| 6–10 | +15 / 0 | 0 / -9 | +24 | 0 |
| 10–18 | +18 / 0 | 0 / -11 | +29 | 0 |
| 18–30 | +21 / 0 | 0 / -13 | +34 | 0 |
| 30–50 | +25 / 0 | 0 / -16 | +41 | 0 |
| 50–80 | +30 / 0 | 0 / -19 | +49 | 0 |
| 80–120 | +35 / 0 | 0 / -22 | +57 | 0 |
| 120–180 | +40 / 0 | 0 / -25 | +65 | 0 |
| 180–250 | +46 / 0 | 0 / -29 | +75 | 0 |
| 250–315 | +52 / 0 | 0 / -32 | +84 | 0 |
| 315–400 | +57 / 0 | 0 / -36 | +93 | 0 |
| 400–500 | +63 / 0 | 0 / -40 | +103 | 0 |
Negative clearance = interference: the shaft is larger than the hole. Values in micrometres (µm, thousandths of a millimetre). Diameter ranges: over the first value, up to and including the second.
Other fits
Values computed from the IT grades and fundamental deviations of ISO 286-1, checked against several published tables. For critical designs the standard itself is what counts.