H7/j6 fit — Locational transition

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

Nominal size

Unit

Result

Ø25.000 H7/j6Transition fit

	Upper	Lower	Max	Min	Tol.
Hole H7	+0.021	0	25.021	25.000	0.021
Shaft j6	+0.009	−0.004	25.009	24.996	0.013

Max clearance: 0.025 mm
Max interference: 0.009 mm
Mean: +0.008 mm

Fit diagram (µm · zero line = nominal)

Hole tolerance zoneShaft tolerance zoneClearanceInterference

About H7/j6

A lighter transition than js6/k6, still seen on older (pre-ISO 286) drawings for ball-bearing inner rings under light, steady load; locates the part but allows hand assembly with only an occasional tap.

At Ø25 mm the hole H7 measures 0 mm to +0.021 mm and the shaft j6 −0.004 mm to +0.009 mm, giving between 0.009 mm interference and 0.025 mm clearance.

How the limits are calculated

Hole H7: fundamental deviation EI = 0, standard tolerance IT7 = 21 µm for 18–30 mm. Shaft j6: fundamental deviation ei = -4 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/j6 limits by size range

Size (mm)	Hole H7	Shaft j6	Clearance min	Clearance max
≤ 3	+0.010 / 0	+0.004 / −0.002	−0.004	+0.012
3 – 6	+0.012 / 0	+0.006 / −0.002	−0.006	+0.014
6 – 10	+0.015 / 0	+0.007 / −0.002	−0.007	+0.017
10 – 18	+0.018 / 0	+0.008 / −0.003	−0.008	+0.021
18 – 30	+0.021 / 0	+0.009 / −0.004	−0.009	+0.025
30 – 50	+0.025 / 0	+0.011 / −0.005	−0.011	+0.030
50 – 80	+0.030 / 0	+0.012 / −0.007	−0.012	+0.037
80 – 120	+0.035 / 0	+0.013 / −0.009	−0.013	+0.044
120 – 180	+0.040 / 0	+0.014 / −0.011	−0.014	+0.051
180 – 250	+0.046 / 0	+0.016 / −0.013	−0.016	+0.059
250 – 315	+0.052 / 0	+0.016 / −0.016	−0.016	+0.068
315 – 400	+0.057 / 0	+0.018 / −0.018	−0.018	+0.075
400 – 500	+0.063 / 0	+0.020 / −0.020	−0.020	+0.083

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/j6 a clearance fit?

Not always — H7/j6 is a transition fit per ISO 286 (see types of fits). At Ø25 mm it gives between 0.009 mm mm interference and 0.025 mm mm clearance, depending which parts of the tolerance zones are paired.

What is the H7/j6 tolerance at 25 mm?

At a nominal size of Ø25 mm, H7 allows a hole diameter from 25.000 to 25.021 mm, and j6 allows a shaft diameter from 24.996 to 25.009 mm.