A11/h11 fit — Very loose fit (shaft basis)
ISO 286 shaft-basis clearance fit. Enter a nominal size to get the limits.
About A11/h11
Shaft-basis equivalent of H11/a11.
At Ø25 mm the hole A11 measures +0.300 mm to +0.430 mm and the shaft h11 −0.130 mm to 0 mm, giving a clearance of 0.300 mm to 0.560 mm.
How the limits are calculated
Hole A11: fundamental deviation ES/EI per ISO 286-1 Table 2, standard tolerance IT11 = 130 µm for 18–30 mm. Shaft h11: fundamental deviation es = 0, IT11 = 130 µm. Clearance = hole − shaft, evaluated at both extremes. See the fundamental deviation table for every letter. Values per ISO 286-1:2010.
A11/h11 limits by size range
| Size (mm) | Hole A11 | Shaft h11 | Clearance min | Clearance max |
|---|---|---|---|---|
| ≤ 3 | +0.330 / +0.270 | 0 / −0.060 | +0.270 | +0.390 |
| 3 – 6 | +0.345 / +0.270 | 0 / −0.075 | +0.270 | +0.420 |
| 6 – 10 | +0.370 / +0.280 | 0 / −0.090 | +0.280 | +0.460 |
| 10 – 18 | +0.400 / +0.290 | 0 / −0.110 | +0.290 | +0.510 |
| 18 – 30 | +0.430 / +0.300 | 0 / −0.130 | +0.300 | +0.560 |
| 30 – 50 | +0.480 / +0.320 | 0 / −0.160 | +0.320 | +0.640 |
| 50 – 80 | +0.550 / +0.360 | 0 / −0.190 | +0.360 | +0.740 |
| 80 – 120 | +0.630 / +0.410 | 0 / −0.220 | +0.410 | +0.850 |
| 120 – 180 | +0.830 / +0.580 | 0 / −0.250 | +0.580 | +1.080 |
| 180 – 250 | +1.110 / +0.820 | 0 / −0.290 | +0.820 | +1.400 |
| 250 – 315 | +1.370 / +1.050 | 0 / −0.320 | +1.050 | +1.690 |
| 315 – 400 | +1.710 / +1.350 | 0 / −0.360 | +1.350 | +2.070 |
| 400 – 500 | +2.050 / +1.650 | 0 / −0.400 | +1.650 | +2.450 |
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 A11/h11 a clearance fit?
Yes — A11/h11 is a clearance fit per ISO 286 (see types of fits). At Ø25 mm it gives a clearance of 0.300 mm to 0.560 mm mm, depending which parts of the tolerance zones are paired.
What is the A11/h11 tolerance at 25 mm?
At a nominal size of Ø25 mm, A11 allows a hole diameter from 25.300 to 25.430 mm, and h11 allows a shaft diameter from 24.870 to 25.000 mm.