H6/k5 fit — Precision transition
ISO 286 hole-basis transition fit. Enter a nominal size to get the limits.
About H6/k5
Precision push fit, e.g. ball-bearing inner rings in instruments.
At Ø25 mm the hole H6 measures 0 mm to +0.013 mm and the shaft k5 +0.002 mm to +0.011 mm, giving between 0.011 mm interference and 0.011 mm clearance.
How the limits are calculated
Hole H6: fundamental deviation EI = 0, standard tolerance IT6 = 13 µm for 18–30 mm. Shaft k5: fundamental deviation ei = 2 µm, IT5 = 9 µm. Clearance = hole − shaft, evaluated at both extremes. See the fundamental deviation table for every letter. Values per ISO 286-1:2010.
H6/k5 limits by size range
| Size (mm) | Hole H6 | Shaft k5 | Clearance min | Clearance max |
|---|---|---|---|---|
| ≤ 3 | +0.006 / 0 | +0.004 / 0 | −0.004 | +0.006 |
| 3 – 6 | +0.008 / 0 | +0.006 / +0.001 | −0.006 | +0.007 |
| 6 – 10 | +0.009 / 0 | +0.007 / +0.001 | −0.007 | +0.008 |
| 10 – 18 | +0.011 / 0 | +0.009 / +0.001 | −0.009 | +0.010 |
| 18 – 30 | +0.013 / 0 | +0.011 / +0.002 | −0.011 | +0.011 |
| 30 – 50 | +0.016 / 0 | +0.013 / +0.002 | −0.013 | +0.014 |
| 50 – 80 | +0.019 / 0 | +0.015 / +0.002 | −0.015 | +0.017 |
| 80 – 120 | +0.022 / 0 | +0.018 / +0.003 | −0.018 | +0.019 |
| 120 – 180 | +0.025 / 0 | +0.021 / +0.003 | −0.021 | +0.022 |
| 180 – 250 | +0.029 / 0 | +0.024 / +0.004 | −0.024 | +0.025 |
| 250 – 315 | +0.032 / 0 | +0.027 / +0.004 | −0.027 | +0.028 |
| 315 – 400 | +0.036 / 0 | +0.029 / +0.004 | −0.029 | +0.032 |
| 400 – 500 | +0.040 / 0 | +0.032 / +0.005 | −0.032 | +0.035 |
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 H6/k5 a clearance fit?
Not always — H6/k5 is a transition fit per ISO 286 (see types of fits). At Ø25 mm it gives between 0.011 mm mm interference and 0.011 mm mm clearance, depending which parts of the tolerance zones are paired.
What is the H6/k5 tolerance at 25 mm?
At a nominal size of Ø25 mm, H6 allows a hole diameter from 25.000 to 25.013 mm, and k5 allows a shaft diameter from 25.002 to 25.011 mm.