H7/p6 fit — Locational interference

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

Nominal size

Unit

Result

Ø25.000 H7/p6Interference fit

	Upper	Lower	Max	Min	Tol.
Hole H7	+0.021	0	25.021	25.000	0.021
Shaft p6	+0.035	+0.022	25.035	25.022	0.013

Max interference: 0.035 mm
Min interference: 0.001 mm
Mean: −0.018 mm

Fit diagram (µm · zero line = nominal)

Hole tolerance zoneShaft tolerance zoneInterference

About H7/p6

Parts that must stay fixed without transmitting large torque: bushes pressed into housings, dowels, gears on shafts with a key. See press fit tolerance for interference by size across the p6–u6 family.

At Ø25 mm the hole H7 measures 0 mm to +0.021 mm and the shaft p6 +0.022 mm to +0.035 mm, giving an interference of 0.001 mm to 0.035 mm.

How the limits are calculated

Hole H7: fundamental deviation EI = 0, standard tolerance IT7 = 21 µm for 18–30 mm. Shaft p6: fundamental deviation ei = 22 µm, IT6 = 13 µm. Clearance = hole − shaft, evaluated at both extremes. See the fundamental deviation table for every letter. Values per ISO 286-1:2010.

H7/p6 limits by size range

Size (mm)	Hole H7	Shaft p6	Clearance min	Clearance max
≤ 3	+0.010 / 0	+0.012 / +0.006	−0.012	+0.004
3 – 6	+0.012 / 0	+0.020 / +0.012	−0.020	0
6 – 10	+0.015 / 0	+0.024 / +0.015	−0.024	0
10 – 18	+0.018 / 0	+0.029 / +0.018	−0.029	0
18 – 30	+0.021 / 0	+0.035 / +0.022	−0.035	−0.001
30 – 50	+0.025 / 0	+0.042 / +0.026	−0.042	−0.001
50 – 80	+0.030 / 0	+0.051 / +0.032	−0.051	−0.002
80 – 120	+0.035 / 0	+0.059 / +0.037	−0.059	−0.002
120 – 180	+0.040 / 0	+0.068 / +0.043	−0.068	−0.003
180 – 250	+0.046 / 0	+0.079 / +0.050	−0.079	−0.004
250 – 315	+0.052 / 0	+0.088 / +0.056	−0.088	−0.004
315 – 400	+0.057 / 0	+0.098 / +0.062	−0.098	−0.005
400 – 500	+0.063 / 0	+0.108 / +0.068	−0.108	−0.005

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/p6 a clearance fit?

No — H7/p6 is an interference fit per ISO 286 (see types of fits). At Ø25 mm it gives an interference of 0.001 mm to 0.035 mm mm, depending which parts of the tolerance zones are paired.

What is the H7/p6 tolerance at 25 mm?

At a nominal size of Ø25 mm, H7 allows a hole diameter from 25.000 to 25.021 mm, and p6 allows a shaft diameter from 25.022 to 25.035 mm.