When to use H9/d9
Large clearance: for lever pins, hinges, parts exposed to dirt or thermal expansion, where free movement matters most.
H9/d9 tolerances for every diameter
| Diameter (mm) | Hole H9 (µm) | Shaft d9 (µm) | Max clearance | Min clearance |
|---|---|---|---|---|
| ≤ 3 | +25 / 0 | -20 / -45 | +70 | +20 |
| 3–6 | +30 / 0 | -30 / -60 | +90 | +30 |
| 6–10 | +36 / 0 | -40 / -76 | +112 | +40 |
| 10–18 | +43 / 0 | -50 / -93 | +136 | +50 |
| 18–30 | +52 / 0 | -65 / -117 | +169 | +65 |
| 30–50 | +62 / 0 | -80 / -142 | +204 | +80 |
| 50–80 | +74 / 0 | -100 / -174 | +248 | +100 |
| 80–120 | +87 / 0 | -120 / -207 | +294 | +120 |
| 120–180 | +100 / 0 | -145 / -245 | +345 | +145 |
| 180–250 | +115 / 0 | -170 / -285 | +400 | +170 |
| 250–315 | +130 / 0 | -190 / -320 | +450 | +190 |
| 315–400 | +140 / 0 | -210 / -350 | +490 | +210 |
| 400–500 | +155 / 0 | -230 / -385 | +540 | +230 |
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.