H7/f7 fit — Close running fit
ISO 286 hole-basis clearance fit. Enter a nominal size to get the limits.
About H7/f7
Sliding parts and journals at moderate speeds with noticeable but small play.
At Ø25 mm the hole H7 measures 0 mm to +0.021 mm and the shaft f7 −0.041 mm to −0.020 mm, giving a clearance of 0.020 mm to 0.062 mm.
How the limits are calculated
Hole H7: fundamental deviation EI = 0, standard tolerance IT7 = 21 µm for 18–30 mm. Shaft f7: fundamental deviation es = -20 µm, IT7 = 21 µm. Clearance = hole − shaft, evaluated at both extremes. See the fundamental deviation table for every letter. Values per ISO 286-1:2010.
H7/f7 limits by size range
| Size (mm) | Hole H7 | Shaft f7 | Clearance min | Clearance max |
|---|---|---|---|---|
| ≤ 3 | +0.010 / 0 | −0.006 / −0.016 | +0.006 | +0.026 |
| 3 – 6 | +0.012 / 0 | −0.010 / −0.022 | +0.010 | +0.034 |
| 6 – 10 | +0.015 / 0 | −0.013 / −0.028 | +0.013 | +0.043 |
| 10 – 18 | +0.018 / 0 | −0.016 / −0.034 | +0.016 | +0.052 |
| 18 – 30 | +0.021 / 0 | −0.020 / −0.041 | +0.020 | +0.062 |
| 30 – 50 | +0.025 / 0 | −0.025 / −0.050 | +0.025 | +0.075 |
| 50 – 80 | +0.030 / 0 | −0.030 / −0.060 | +0.030 | +0.090 |
| 80 – 120 | +0.035 / 0 | −0.036 / −0.071 | +0.036 | +0.106 |
| 120 – 180 | +0.040 / 0 | −0.043 / −0.083 | +0.043 | +0.123 |
| 180 – 250 | +0.046 / 0 | −0.050 / −0.096 | +0.050 | +0.142 |
| 250 – 315 | +0.052 / 0 | −0.056 / −0.108 | +0.056 | +0.160 |
| 315 – 400 | +0.057 / 0 | −0.062 / −0.119 | +0.062 | +0.176 |
| 400 – 500 | +0.063 / 0 | −0.068 / −0.131 | +0.068 | +0.194 |
Deviations in mm at the upper end of each range; negative clearance = interference. Clearance columns are shown on wider screens. Sub-ranges (e.g. 18–24 / 24–30) can differ for r, s, t, u, v, x, y, z — use the calculator for the exact size. “—” means ISO 286 doesn't define this class below that size (e.g. t only starts at 24 mm).
Is H7/f7 a clearance fit?
Yes — H7/f7 is a clearance fit per ISO 286 (see types of fits). At Ø25 mm it gives a clearance of 0.020 mm to 0.062 mm mm, depending which parts of the tolerance zones are paired.
What is the H7/f7 tolerance at 25 mm?
At a nominal size of Ø25 mm, H7 allows a hole diameter from 25.000 to 25.021 mm, and f7 allows a shaft diameter from 24.959 to 24.980 mm.