H7/h6 fit — Locational clearance

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

Unit

Result

Ø25.000 H7/h6Clearance fit
UpperLowerMaxMin
Hole H7+0.021025.02125.000
Shaft h60−0.01325.00024.987
Max clearance
0.034 mm
Min clearance
0.000 mm
Mean
+0.017 mm

Fit diagram (µm · zero line = nominal)

0µmHole H7Shaft h6Clearance+21−13max +34min 0
Hole tolerance zoneShaft tolerance zoneClearance

About H7/h6

Precisely located parts that can still be assembled and turned by hand: gears on shafts fixed by keys, pulleys, centring flanges.

At Ø25 mm the hole H7 measures 0 mm to +0.021 mm and the shaft h6 −0.013 mm to 0 mm, giving a clearance of 0.000 mm to 0.034 mm.

How the limits are calculated

Hole H7: fundamental deviation EI = 0, standard tolerance IT7 = 21 µm for 18–30 mm. Shaft h6: fundamental deviation es = 0, IT6 = 13 µm. Clearance = hole − shaft, evaluated at both extremes. Values per ISO 286-1:2010.

H7/h6 limits by size range

Size (mm)Hole H7Shaft h6
≤ 3+0.010 / 00 / −0.006
3 – 6+0.012 / 00 / −0.008
6 – 10+0.015 / 00 / −0.009
10 – 18+0.018 / 00 / −0.011
18 – 30+0.021 / 00 / −0.013
30 – 50+0.025 / 00 / −0.016
50 – 80+0.030 / 00 / −0.019
80 – 120+0.035 / 00 / −0.022
120 – 180+0.040 / 00 / −0.025
180 – 250+0.046 / 00 / −0.029
250 – 315+0.052 / 00 / −0.032
315 – 400+0.057 / 00 / −0.036
400 – 500+0.063 / 00 / −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.

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