u7 tolerance (shaft, IT7)
Shaft tolerance class u7 per ISO 286-1:2010: fundamental deviation ei +18 … +540, grade IT7 (10 µm at ≤ 3 mm to 63 µm at 400–500 mm). For an exact size, open the calculator with u7 selected.
- Type
- Shaft
- Grade
- IT7
- Tolerance
- 10 … 63 µm
- Fund. deviation
- ei +18 … +540 µm
u7 limits by size range
| Size (mm) | Upper (µm) | Lower (µm) | Ø max (mm) | Ø min (mm) | Upper (mm) | Lower (mm) | Dev. (in) |
|---|---|---|---|---|---|---|---|
| ≤ 3 | +28 | +18 | 3.028 | 3.018 | +0.028 | +0.018 | +0.00110 / +0.00071 |
| 3 – 6 | +35 | +23 | 6.035 | 6.023 | +0.035 | +0.023 | +0.00138 / +0.00091 |
| 6 – 10 | +43 | +28 | 10.043 | 10.028 | +0.043 | +0.028 | +0.00169 / +0.00110 |
| 10 – 14 | +51 | +33 | 14.051 | 14.033 | +0.051 | +0.033 | +0.00201 / +0.00130 |
| 14 – 18 | +51 | +33 | 18.051 | 18.033 | +0.051 | +0.033 | +0.00201 / +0.00130 |
| 18 – 24 | +62 | +41 | 24.062 | 24.041 | +0.062 | +0.041 | +0.00244 / +0.00161 |
| 24 – 30 | +69 | +48 | 30.069 | 30.048 | +0.069 | +0.048 | +0.00272 / +0.00189 |
| 30 – 40 | +85 | +60 | 40.085 | 40.060 | +0.085 | +0.060 | +0.00335 / +0.00236 |
| 40 – 50 | +95 | +70 | 50.095 | 50.070 | +0.095 | +0.070 | +0.00374 / +0.00276 |
| 50 – 65 | +117 | +87 | 65.117 | 65.087 | +0.117 | +0.087 | +0.00461 / +0.00343 |
| 65 – 80 | +132 | +102 | 80.132 | 80.102 | +0.132 | +0.102 | +0.00520 / +0.00402 |
| 80 – 100 | +159 | +124 | 100.159 | 100.124 | +0.159 | +0.124 | +0.00626 / +0.00488 |
| 100 – 120 | +179 | +144 | 120.179 | 120.144 | +0.179 | +0.144 | +0.00705 / +0.00567 |
| 120 – 140 | +210 | +170 | 140.210 | 140.170 | +0.210 | +0.170 | +0.00827 / +0.00669 |
| 140 – 160 | +230 | +190 | 160.230 | 160.190 | +0.230 | +0.190 | +0.00906 / +0.00748 |
| 160 – 180 | +250 | +210 | 180.250 | 180.210 | +0.250 | +0.210 | +0.00984 / +0.00827 |
| 180 – 200 | +282 | +236 | 200.282 | 200.236 | +0.282 | +0.236 | +0.01110 / +0.00929 |
| 200 – 225 | +304 | +258 | 225.304 | 225.258 | +0.304 | +0.258 | +0.01197 / +0.01016 |
| 225 – 250 | +330 | +284 | 250.330 | 250.284 | +0.330 | +0.284 | +0.01299 / +0.01118 |
| 250 – 280 | +367 | +315 | 280.367 | 280.315 | +0.367 | +0.315 | +0.01445 / +0.01240 |
| 280 – 315 | +402 | +350 | 315.402 | 315.350 | +0.402 | +0.350 | +0.01583 / +0.01378 |
| 315 – 355 | +447 | +390 | 355.447 | 355.390 | +0.447 | +0.390 | +0.01760 / +0.01535 |
| 355 – 400 | +492 | +435 | 400.492 | 400.435 | +0.492 | +0.435 | +0.01937 / +0.01713 |
| 400 – 450 | +553 | +490 | 450.553 | 450.490 | +0.553 | +0.490 | +0.02177 / +0.01929 |
| 450 – 500 | +603 | +540 | 500.603 | 500.540 | +0.603 | +0.540 | +0.02374 / +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 u7
u7 denotes a shaft tolerance zone with heavy interference deviation in the ISO 286 system. It is used in H8/u7 (Coarser heavy press or shrink fit for permanent assemblies.).
At Ø25 mm u7 is +0.069 / +0.048 mm, i.e. 25.048 to 25.069 mm.
How the limits are calculated
u7 uses grade IT7 (a standard tolerance of 21 µm at 18–30 mm). Fundamental deviation: ei is tabulated directly by ISO 286-1 Table 2; es = ei + IT7. See the fundamental deviation table for every letter. Values per ISO 286-1:2010.