Tolerance charts
ISO 286 tolerance charts: every hole and shaft class up to 500 mm
Behind »Ø25 H7« or »Ø12 g6« on a drawing are two numbers: the upper and the lower deviation. Here is the full chart up to 500 mm for each common ISO tolerance class – 26 hole classes and 25 shaft classes, each with the fits it appears in.
Letter and number: how to read a tolerance class
An ISO tolerance class under ISO 286 is a letter followed by a number. Capital letters (H7, G7, K7) apply to holes and other internal features, small letters (h6, g6, k6) to shafts and external features. The letter sets where the tolerance zone lies relative to the nominal size; H and h start exactly at the nominal size. The number is the standard tolerance grade: the higher it is, the wider the zone. Letter, number and nominal size together give the deviations.
Two classes on the same nominal size make a fit, such as H7/g6. Whether it has clearance, is a transition fit or an interference fit is shown on every class page.
Holes: tolerance classes H, G, F, E, D, JS, K, M, N, P, R, S
Deviations at Ø25 mm in µm. Open a class for its full chart up to 500 mm.
| Class | Deviations at Ø25 | Limits (mm) |
|---|---|---|
| H6 | +13 / 0 µm | 25.000 – 25.013 |
| H7 | +21 / 0 µm | 25.000 – 25.021 |
| H8 | +33 / 0 µm | 25.000 – 25.033 |
| H9 | +52 / 0 µm | 25.000 – 25.052 |
| H10 | +84 / 0 µm | 25.000 – 25.084 |
| H11 | +130 / 0 µm | 25.000 – 25.130 |
| G6 | +20 / +7 µm | 25.007 – 25.020 |
| G7 | +28 / +7 µm | 25.007 – 25.028 |
| F7 | +41 / +20 µm | 25.020 – 25.041 |
| F8 | +53 / +20 µm | 25.020 – 25.053 |
| E8 | +73 / +40 µm | 25.040 – 25.073 |
| E9 | +92 / +40 µm | 25.040 – 25.092 |
| D9 | +117 / +65 µm | 25.065 – 25.117 |
| D10 | +149 / +65 µm | 25.065 – 25.149 |
| JS6 | +6.5 / −6.5 µm | 24.9935 – 25.0065 |
| JS7 | +10.5 / −10.5 µm | 24.9895 – 25.0105 |
| K6 | +2 / −11 µm | 24.989 – 25.002 |
| K7 | +6 / −15 µm | 24.985 – 25.006 |
| M6 | −4 / −17 µm | 24.983 – 24.996 |
| M7 | 0 / −21 µm | 24.979 – 25.000 |
| N6 | −11 / −24 µm | 24.976 – 24.989 |
| N7 | −7 / −28 µm | 24.972 – 24.993 |
| P6 | −18 / −31 µm | 24.969 – 24.982 |
| P7 | −14 / −35 µm | 24.965 – 24.986 |
| R7 | −20 / −41 µm | 24.959 – 24.980 |
| S7 | −27 / −48 µm | 24.952 – 24.973 |
Shafts: tolerance classes h, g, f, e, d, js, k, m, n, p, r, s
Deviations at Ø25 mm in µm.
| Class | Deviations at Ø25 | Limits (mm) |
|---|---|---|
| h5 | 0 / −9 µm | 24.991 – 25.000 |
| h6 | 0 / −13 µm | 24.987 – 25.000 |
| h7 | 0 / −21 µm | 24.979 – 25.000 |
| h8 | 0 / −33 µm | 24.967 – 25.000 |
| h9 | 0 / −52 µm | 24.948 – 25.000 |
| h11 | 0 / −130 µm | 24.870 – 25.000 |
| g5 | −7 / −16 µm | 24.984 – 24.993 |
| g6 | −7 / −20 µm | 24.980 – 24.993 |
| f6 | −20 / −33 µm | 24.967 – 24.980 |
| f7 | −20 / −41 µm | 24.959 – 24.980 |
| e7 | −40 / −61 µm | 24.939 – 24.960 |
| e8 | −40 / −73 µm | 24.927 – 24.960 |
| d9 | −65 / −117 µm | 24.883 – 24.935 |
| d10 | −65 / −149 µm | 24.851 – 24.935 |
| js5 | +4.5 / −4.5 µm | 24.9955 – 25.0045 |
| js6 | +6.5 / −6.5 µm | 24.9935 – 25.0065 |
| k5 | +11 / +2 µm | 25.002 – 25.011 |
| k6 | +15 / +2 µm | 25.002 – 25.015 |
| m5 | +17 / +8 µm | 25.008 – 25.017 |
| m6 | +21 / +8 µm | 25.008 – 25.021 |
| n5 | +24 / +15 µm | 25.015 – 25.024 |
| n6 | +28 / +15 µm | 25.015 – 25.028 |
| p6 | +35 / +22 µm | 25.022 – 25.035 |
| r6 | +41 / +28 µm | 25.028 – 25.041 |
| s6 | +48 / +35 µm | 25.035 – 25.048 |
Hole-basis and shaft-basis systems
So that not every combination has to be made and gauged, one side is held fixed. In the hole-basis system the hole is always H (usually H7) and the shaft decides the fit: clearance with g6, transition with k6, interference with s6. In the shaft-basis system the shaft is always h (such as h6) and the hole changes.