When to use H7/m6
Tighter than k6: press assembly. For parts that must not move and are rarely taken apart.
H7/m6 tolerances for every diameter
| Diameter (mm) | Hole H7 (µm) | Shaft m6 (µm) | Max clearance | Min clearance |
|---|---|---|---|---|
| ≤ 3 | +10 / 0 | +8 / +2 | +8 | -8 |
| 3–6 | +12 / 0 | +12 / +4 | +8 | -12 |
| 6–10 | +15 / 0 | +15 / +6 | +9 | -15 |
| 10–18 | +18 / 0 | +18 / +7 | +11 | -18 |
| 18–30 | +21 / 0 | +21 / +8 | +13 | -21 |
| 30–50 | +25 / 0 | +25 / +9 | +16 | -25 |
| 50–80 | +30 / 0 | +30 / +11 | +19 | -30 |
| 80–120 | +35 / 0 | +35 / +13 | +22 | -35 |
| 120–180 | +40 / 0 | +40 / +15 | +25 | -40 |
| 180–250 | +46 / 0 | +46 / +17 | +29 | -46 |
| 250–315 | +52 / 0 | +52 / +20 | +32 | -52 |
| 315–400 | +57 / 0 | +57 / +21 | +36 | -57 |
| 400–500 | +63 / 0 | +63 / +23 | +40 | -63 |
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.