Shaft tolerance zone
Lowercase letters identify shaft tolerance zones.
ISO 286 REFERENCE TABLE · SHAFT
n6 tolerance chart: ISO 286 shaft limits by size
Static n6 deviations and shaft limits at the upper-bound nominal of every ISO 286 size band from 1 to 500 mm.This page answers a class-specific n6 tolerance chart query. The ISO 286 fits calculator remains the tool for arbitrary nominal sizes, paired hole/shaft callouts, measured values, and shareable calculations.
13 ISO 286 SIZE BANDS
n6 shaft limits by representative nominal size
Each representative nominal is the upper boundary of its displayed size band. Deviations and IT width are shown in micrometres; the resulting minimum and maximum are shown in millimetres.| Size band (mm) | Representative nominal (mm) | Upper deviation (µm) | Lower deviation (µm) | IT6 width (µm) | Minimum / maximum (mm) |
|---|---|---|---|---|---|
| [1, 3] | 3 | +10 | +4 | 6 | 3.004 / 3.010 |
| (3, 6] | 6 | +16 | +8 | 8 | 6.008 / 6.016 |
| (6, 10] | 10 | +19 | +10 | 9 | 10.010 / 10.019 |
| (10, 18] | 18 | +23 | +12 | 11 | 18.012 / 18.023 |
| (18, 30] | 30 | +28 | +15 | 13 | 30.015 / 30.028 |
| (30, 50] | 50 | +33 | +17 | 16 | 50.017 / 50.033 |
| (50, 80] | 80 | +39 | +20 | 19 | 80.020 / 80.039 |
| (80, 120] | 120 | +45 | +23 | 22 | 120.023 / 120.045 |
| (120, 180] | 180 | +52 | +27 | 25 | 180.027 / 180.052 |
| (180, 250] | 250 | +60 | +31 | 29 | 250.031 / 250.060 |
| (250, 315] | 315 | +66 | +34 | 32 | 315.034 / 315.066 |
| (315, 400] | 400 | +73 | +37 | 36 | 400.037 / 400.073 |
| (400, 500] | 500 | +80 | +40 | 40 | 500.040 / 500.080 |
The IT6 tolerance width is constant within each displayed size band. Values shown are calculated at the representative upper-bound nominal. Some letter zones use finer fundamental-deviation sub-bands, so deviations may vary within a displayed band; use the calculator for the exact nominal.
Within a band where the deviations are unchanged, the micrometre deviations stay fixed while the absolute millimetre limits move with the selected nominal size.
DRAWING EXAMPLES
Common n6 callouts
n6 is the shaft member of the H7/n6 firm transition fit, with positive fundamental deviation. Examples you can check across different size bands include:25 MM WORKED CALLOUT25 n6 → 25.015 / 25.028 mm
- Upper deviation
- +28 µm
- Lower deviation
- +15 µm
- IT6 width
- 13 µm
READ THE CLASS CORRECTLY
n6: shaft zone n, IT grade 6
IT tolerance grade
The grade selects the published tolerance width for each nominal-size band.
Deviation to absolute limit
Each deviation is added to the exact nominal diameter after conversion from micrometres to millimetres.
This static table is an engineering reference, not a replacement for a controlled drawing or licensed ISO 286 standard. Confirm standard edition, feature function, geometry, surface finish, and inspection method.
Return to the ISO 286 fits & tolerance calculator