K6/h5 fit — Precision transition (shaft basis)
ISO 286 shaft-basis transition fit. Enter a nominal size to get the limits.
About K6/h5
Shaft-basis equivalent of H6/k5 — a precision push fit for parts located on a shared ground reference shaft, e.g. several instrument components on one spindle.
At Ø25 mm the hole K6 measures −0.011 mm to +0.002 mm and the shaft h5 −0.009 mm to 0 mm, giving between 0.011 mm interference and 0.011 mm clearance.
How the limits are calculated
Hole K6: fundamental deviation ES/EI per ISO 286-1 Table 2, standard tolerance IT6 = 13 µm for 18–30 mm. Shaft h5: fundamental deviation es = 0, IT5 = 9 µm. Clearance = hole − shaft, evaluated at both extremes. See the fundamental deviation table for every letter. Values per ISO 286-1:2010.
K6/h5 limits by size range
| Size (mm) | Hole K6 | Shaft h5 | Clearance min | Clearance max |
|---|---|---|---|---|
| ≤ 3 | 0 / −0.006 | 0 / −0.004 | −0.006 | +0.004 |
| 3 – 6 | +0.002 / −0.006 | 0 / −0.005 | −0.006 | +0.007 |
| 6 – 10 | +0.002 / −0.007 | 0 / −0.006 | −0.007 | +0.008 |
| 10 – 18 | +0.002 / −0.009 | 0 / −0.008 | −0.009 | +0.010 |
| 18 – 30 | +0.002 / −0.011 | 0 / −0.009 | −0.011 | +0.011 |
| 30 – 50 | +0.003 / −0.013 | 0 / −0.011 | −0.013 | +0.014 |
| 50 – 80 | +0.004 / −0.015 | 0 / −0.013 | −0.015 | +0.017 |
| 80 – 120 | +0.004 / −0.018 | 0 / −0.015 | −0.018 | +0.019 |
| 120 – 180 | +0.004 / −0.021 | 0 / −0.018 | −0.021 | +0.022 |
| 180 – 250 | +0.005 / −0.024 | 0 / −0.020 | −0.024 | +0.025 |
| 250 – 315 | +0.005 / −0.027 | 0 / −0.023 | −0.027 | +0.028 |
| 315 – 400 | +0.007 / −0.029 | 0 / −0.025 | −0.029 | +0.032 |
| 400 – 500 | +0.008 / −0.032 | 0 / −0.027 | −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 K6/h5 a clearance fit?
Not always — K6/h5 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 K6/h5 tolerance at 25 mm?
At a nominal size of Ø25 mm, K6 allows a hole diameter from 24.989 to 25.002 mm, and h5 allows a shaft diameter from 24.991 to 25.000 mm.