u6 tolerance (shaft, IT6)
Shaft tolerance class u6 per ISO 286-1:2010: fundamental deviation ei +18 … +540, grade IT6 (6 µm at ≤ 3 mm to 40 µm at 400–500 mm). For an exact size, open the calculator with u6 selected.
- Type
- Shaft
- Grade
- IT6
- Tolerance
- 6 … 40 µm
- Fund. deviation
- ei +18 … +540 µm
u6 limits by size range
| Size (mm) | Upper (µm) | Lower (µm) | Ø max (mm) | Ø min (mm) | Upper (mm) | Lower (mm) | Dev. (in) |
|---|---|---|---|---|---|---|---|
| ≤ 3 | +24 | +18 | 3.024 | 3.018 | +0.024 | +0.018 | +0.00094 / +0.00071 |
| 3 – 6 | +31 | +23 | 6.031 | 6.023 | +0.031 | +0.023 | +0.00122 / +0.00091 |
| 6 – 10 | +37 | +28 | 10.037 | 10.028 | +0.037 | +0.028 | +0.00146 / +0.00110 |
| 10 – 14 | +44 | +33 | 14.044 | 14.033 | +0.044 | +0.033 | +0.00173 / +0.00130 |
| 14 – 18 | +44 | +33 | 18.044 | 18.033 | +0.044 | +0.033 | +0.00173 / +0.00130 |
| 18 – 24 | +54 | +41 | 24.054 | 24.041 | +0.054 | +0.041 | +0.00213 / +0.00161 |
| 24 – 30 | +61 | +48 | 30.061 | 30.048 | +0.061 | +0.048 | +0.00240 / +0.00189 |
| 30 – 40 | +76 | +60 | 40.076 | 40.060 | +0.076 | +0.060 | +0.00299 / +0.00236 |
| 40 – 50 | +86 | +70 | 50.086 | 50.070 | +0.086 | +0.070 | +0.00339 / +0.00276 |
| 50 – 65 | +106 | +87 | 65.106 | 65.087 | +0.106 | +0.087 | +0.00417 / +0.00343 |
| 65 – 80 | +121 | +102 | 80.121 | 80.102 | +0.121 | +0.102 | +0.00476 / +0.00402 |
| 80 – 100 | +146 | +124 | 100.146 | 100.124 | +0.146 | +0.124 | +0.00575 / +0.00488 |
| 100 – 120 | +166 | +144 | 120.166 | 120.144 | +0.166 | +0.144 | +0.00654 / +0.00567 |
| 120 – 140 | +195 | +170 | 140.195 | 140.170 | +0.195 | +0.170 | +0.00768 / +0.00669 |
| 140 – 160 | +215 | +190 | 160.215 | 160.190 | +0.215 | +0.190 | +0.00846 / +0.00748 |
| 160 – 180 | +235 | +210 | 180.235 | 180.210 | +0.235 | +0.210 | +0.00925 / +0.00827 |
| 180 – 200 | +265 | +236 | 200.265 | 200.236 | +0.265 | +0.236 | +0.01043 / +0.00929 |
| 200 – 225 | +287 | +258 | 225.287 | 225.258 | +0.287 | +0.258 | +0.01130 / +0.01016 |
| 225 – 250 | +313 | +284 | 250.313 | 250.284 | +0.313 | +0.284 | +0.01232 / +0.01118 |
| 250 – 280 | +347 | +315 | 280.347 | 280.315 | +0.347 | +0.315 | +0.01366 / +0.01240 |
| 280 – 315 | +382 | +350 | 315.382 | 315.350 | +0.382 | +0.350 | +0.01504 / +0.01378 |
| 315 – 355 | +426 | +390 | 355.426 | 355.390 | +0.426 | +0.390 | +0.01677 / +0.01535 |
| 355 – 400 | +471 | +435 | 400.471 | 400.435 | +0.471 | +0.435 | +0.01854 / +0.01713 |
| 400 – 450 | +530 | +490 | 450.530 | 450.490 | +0.530 | +0.490 | +0.02087 / +0.01929 |
| 450 – 500 | +580 | +540 | 500.580 | 500.540 | +0.580 | +0.540 | +0.02283 / +0.02126 |
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 u6
u6 denotes a shaft tolerance zone with heavy interference deviation in the ISO 286 system. It is used in H7/u6 (Heavy press or shrink fit for permanent assemblies under high load; requires heating the hub or cooling the shaft.).
At Ø25 mm u6 is +0.061 / +0.048 mm, i.e. 25.048 to 25.061 mm.
How the limits are calculated
u6 uses grade IT6 (a standard tolerance of 13 µm at 18–30 mm). Fundamental deviation: ei is tabulated directly by ISO 286-1 Table 2; es = ei + IT6. See the fundamental deviation table for every letter. Values per ISO 286-1:2010.