H9/d9 fit — Free running fit

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

Unit

Result

Ø25.000 H9/d9Clearance fit
UpperLowerMaxMin
Hole H9+0.052025.05225.000
Shaft d9−0.065−0.11724.93524.883
Max clearance
0.169 mm
Min clearance
0.065 mm
Mean
+0.117 mm

Fit diagram (µm · zero line = nominal)

0µmHole H9Shaft d9Clearance+52−65−117max +169min +65
Hole tolerance zoneShaft tolerance zoneClearance

About H9/d9

Shafts running in plain bearings with wide temperature variation, high speed or heavy journal pressure.

At Ø25 mm the hole H9 measures 0 mm to +0.052 mm and the shaft d9 −0.117 mm to −0.065 mm, giving a clearance of 0.065 mm to 0.169 mm.

How the limits are calculated

Hole H9: fundamental deviation EI = 0, standard tolerance IT9 = 52 µm for 18–30 mm. Shaft d9: fundamental deviation es = -65 µm, IT9 = 52 µm. Clearance = hole − shaft, evaluated at both extremes. Values per ISO 286-1:2010.

H9/d9 limits by size range

Size (mm)Hole H9Shaft d9
≤ 3+0.025 / 0−0.020 / −0.045
3 – 6+0.030 / 0−0.030 / −0.060
6 – 10+0.036 / 0−0.040 / −0.076
10 – 18+0.043 / 0−0.050 / −0.093
18 – 30+0.052 / 0−0.065 / −0.117
30 – 50+0.062 / 0−0.080 / −0.142
50 – 80+0.074 / 0−0.100 / −0.174
80 – 120+0.087 / 0−0.120 / −0.207
120 – 180+0.100 / 0−0.145 / −0.245
180 – 250+0.115 / 0−0.170 / −0.285
250 – 315+0.130 / 0−0.190 / −0.320
315 – 400+0.140 / 0−0.210 / −0.350
400 – 500+0.155 / 0−0.230 / −0.385

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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