When to use H7/k6
Slight interference on average: assembled with a mallet or light press. Classic for pulleys, gears and couplings with a key, bearing inner rings under normal loads.
H7/k6 tolerances for every diameter
| Diameter (mm) | Hole H7 (µm) | Shaft k6 (µm) | Max clearance | Min clearance |
|---|---|---|---|---|
| ≤ 3 | +10 / 0 | +6 / 0 | +10 | -6 |
| 3–6 | +12 / 0 | +9 / +1 | +11 | -9 |
| 6–10 | +15 / 0 | +10 / +1 | +14 | -10 |
| 10–18 | +18 / 0 | +12 / +1 | +17 | -12 |
| 18–30 | +21 / 0 | +15 / +2 | +19 | -15 |
| 30–50 | +25 / 0 | +18 / +2 | +23 | -18 |
| 50–80 | +30 / 0 | +21 / +2 | +28 | -21 |
| 80–120 | +35 / 0 | +25 / +3 | +32 | -25 |
| 120–180 | +40 / 0 | +28 / +3 | +37 | -28 |
| 180–250 | +46 / 0 | +33 / +4 | +42 | -33 |
| 250–315 | +52 / 0 | +36 / +4 | +48 | -36 |
| 315–400 | +57 / 0 | +40 / +4 | +53 | -40 |
| 400–500 | +63 / 0 | +45 / +5 | +58 | -45 |
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.