H7/m6 fit — Locational transition

ISO 286 hole-basis transition fit. Enter a nominal size to get the limits.

Nominal size

Unit

Result

Ø25.000 H7/m6Transition fit

	Upper	Lower	Max	Min	Tol.
Hole H7	+0.021	0	25.021	25.000	0.021
Shaft m6	+0.021	+0.008	25.021	25.008	0.013

Max clearance: 0.013 mm
Max interference: 0.021 mm
Mean: −0.004 mm

Fit diagram (µm · zero line = nominal)

Hole tolerance zoneShaft tolerance zoneClearanceInterference

About H7/m6

Tighter than k6; parts that must not move under vibration but are still removable: bearing bushes, gears, couplings.

At Ø25 mm the hole H7 measures 0 mm to +0.021 mm and the shaft m6 +0.008 mm to +0.021 mm, giving between 0.021 mm interference and 0.013 mm clearance.

How the limits are calculated

Hole H7: fundamental deviation EI = 0, standard tolerance IT7 = 21 µm for 18–30 mm. Shaft m6: fundamental deviation ei = 8 µm, IT6 = 13 µm. Clearance = hole − shaft, evaluated at both extremes. Values per ISO 286-1:2010.

H7/m6 limits by size range

Size (mm)	Hole H7	Shaft m6	Clearance min	Clearance max
≤ 3	+0.010 / 0	+0.008 / +0.002	−0.008	+0.008
3 – 6	+0.012 / 0	+0.012 / +0.004	−0.012	+0.008
6 – 10	+0.015 / 0	+0.015 / +0.006	−0.015	+0.009
10 – 18	+0.018 / 0	+0.018 / +0.007	−0.018	+0.011
18 – 30	+0.021 / 0	+0.021 / +0.008	−0.021	+0.013
30 – 50	+0.025 / 0	+0.025 / +0.009	−0.025	+0.016
50 – 80	+0.030 / 0	+0.030 / +0.011	−0.030	+0.019
80 – 120	+0.035 / 0	+0.035 / +0.013	−0.035	+0.022
120 – 180	+0.040 / 0	+0.040 / +0.015	−0.040	+0.025
180 – 250	+0.046 / 0	+0.046 / +0.017	−0.046	+0.029
250 – 315	+0.052 / 0	+0.052 / +0.020	−0.052	+0.032
315 – 400	+0.057 / 0	+0.057 / +0.021	−0.057	+0.036
400 – 500	+0.063 / 0	+0.063 / +0.023	−0.063	+0.040

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.