K6 tolerance (hole, IT6)
Hole tolerance class K6 per ISO 286-1:2010: fundamental deviation ES 0 … +8, grade IT6 (6 µm at ≤ 3 mm to 40 µm at 400–500 mm). For an exact size, open the calculator with K6 selected.
- Type
- Hole
- Grade
- IT6
- Tolerance
- 6 … 40 µm
- Fund. deviation
- ES 0 … +8 µm
K6 limits by size range
| Size (mm) | Upper (µm) | Lower (µm) | Ø max (mm) | Ø min (mm) | Upper (mm) | Lower (mm) | Dev. (in) |
|---|---|---|---|---|---|---|---|
| ≤ 3 | 0 | −6 | 3.000 | 2.994 | 0 | −0.006 | 0 / −0.00024 |
| 3 – 6 | +2 | −6 | 6.002 | 5.994 | +0.002 | −0.006 | +0.00008 / −0.00024 |
| 6 – 10 | +2 | −7 | 10.002 | 9.993 | +0.002 | −0.007 | +0.00008 / −0.00028 |
| 10 – 14 | +2 | −9 | 14.002 | 13.991 | +0.002 | −0.009 | +0.00008 / −0.00035 |
| 14 – 18 | +2 | −9 | 18.002 | 17.991 | +0.002 | −0.009 | +0.00008 / −0.00035 |
| 18 – 24 | +2 | −11 | 24.002 | 23.989 | +0.002 | −0.011 | +0.00008 / −0.00043 |
| 24 – 30 | +2 | −11 | 30.002 | 29.989 | +0.002 | −0.011 | +0.00008 / −0.00043 |
| 30 – 40 | +3 | −13 | 40.003 | 39.987 | +0.003 | −0.013 | +0.00012 / −0.00051 |
| 40 – 50 | +3 | −13 | 50.003 | 49.987 | +0.003 | −0.013 | +0.00012 / −0.00051 |
| 50 – 65 | +4 | −15 | 65.004 | 64.985 | +0.004 | −0.015 | +0.00016 / −0.00059 |
| 65 – 80 | +4 | −15 | 80.004 | 79.985 | +0.004 | −0.015 | +0.00016 / −0.00059 |
| 80 – 100 | +4 | −18 | 100.004 | 99.982 | +0.004 | −0.018 | +0.00016 / −0.00071 |
| 100 – 120 | +4 | −18 | 120.004 | 119.982 | +0.004 | −0.018 | +0.00016 / −0.00071 |
| 120 – 140 | +4 | −21 | 140.004 | 139.979 | +0.004 | −0.021 | +0.00016 / −0.00083 |
| 140 – 160 | +4 | −21 | 160.004 | 159.979 | +0.004 | −0.021 | +0.00016 / −0.00083 |
| 160 – 180 | +4 | −21 | 180.004 | 179.979 | +0.004 | −0.021 | +0.00016 / −0.00083 |
| 180 – 200 | +5 | −24 | 200.005 | 199.976 | +0.005 | −0.024 | +0.00020 / −0.00094 |
| 200 – 225 | +5 | −24 | 225.005 | 224.976 | +0.005 | −0.024 | +0.00020 / −0.00094 |
| 225 – 250 | +5 | −24 | 250.005 | 249.976 | +0.005 | −0.024 | +0.00020 / −0.00094 |
| 250 – 280 | +5 | −27 | 280.005 | 279.973 | +0.005 | −0.027 | +0.00020 / −0.00106 |
| 280 – 315 | +5 | −27 | 315.005 | 314.973 | +0.005 | −0.027 | +0.00020 / −0.00106 |
| 315 – 355 | +7 | −29 | 355.007 | 354.971 | +0.007 | −0.029 | +0.00028 / −0.00114 |
| 355 – 400 | +7 | −29 | 400.007 | 399.971 | +0.007 | −0.029 | +0.00028 / −0.00114 |
| 400 – 450 | +8 | −32 | 450.008 | 449.968 | +0.008 | −0.032 | +0.00031 / −0.00126 |
| 450 – 500 | +8 | −32 | 500.008 | 499.968 | +0.008 | −0.032 | +0.00031 / −0.00126 |
Deviations at the upper end of each range (Ø columns use that size); use the calculator for the exact size. — : not defined by ISO 286 for that size. Upper/Lower (mm) and inch columns are shown on wider screens.
About K6
K6 denotes a hole tolerance zone with transition deviation in the ISO 286 system. It is used in 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 K6 is +0.002 / −0.011 mm, i.e. 24.989 to 25.002 mm.
How the limits are calculated
K6 uses grade IT6 (a standard tolerance of 13 µm at 18–30 mm). Fundamental deviation: ES = −ei + Δ (Δ = ITn − IT(n−1), applied up to IT8 for K/M/N and IT7 otherwise); IT6 sets the width below ES. See the fundamental deviation table for every letter. Values per ISO 286-1:2010.