h12 tolerance (shaft, IT12)
Shaft tolerance class h12 per ISO 286-1:2010: fundamental deviation es = 0, grade IT12 (100 µm at ≤ 3 mm to 630 µm at 400–500 mm). For an exact size, open the calculator with h12 selected.
- Type
- Shaft
- Grade
- IT12
- Tolerance
- 100 … 630 µm
- Fund. deviation
- es = 0
h12 limits by size range
| Size (mm) | Upper (µm) | Lower (µm) | Ø max (mm) | Ø min (mm) | Upper (mm) | Lower (mm) | Dev. (in) |
|---|---|---|---|---|---|---|---|
| ≤ 3 | 0 | −100 | 3.000 | 2.900 | 0 | −0.100 | 0 / −0.00394 |
| 3 – 6 | 0 | −120 | 6.000 | 5.880 | 0 | −0.120 | 0 / −0.00472 |
| 6 – 10 | 0 | −150 | 10.000 | 9.850 | 0 | −0.150 | 0 / −0.00591 |
| 10 – 14 | 0 | −180 | 14.000 | 13.820 | 0 | −0.180 | 0 / −0.00709 |
| 14 – 18 | 0 | −180 | 18.000 | 17.820 | 0 | −0.180 | 0 / −0.00709 |
| 18 – 24 | 0 | −210 | 24.000 | 23.790 | 0 | −0.210 | 0 / −0.00827 |
| 24 – 30 | 0 | −210 | 30.000 | 29.790 | 0 | −0.210 | 0 / −0.00827 |
| 30 – 40 | 0 | −250 | 40.000 | 39.750 | 0 | −0.250 | 0 / −0.00984 |
| 40 – 50 | 0 | −250 | 50.000 | 49.750 | 0 | −0.250 | 0 / −0.00984 |
| 50 – 65 | 0 | −300 | 65.000 | 64.700 | 0 | −0.300 | 0 / −0.01181 |
| 65 – 80 | 0 | −300 | 80.000 | 79.700 | 0 | −0.300 | 0 / −0.01181 |
| 80 – 100 | 0 | −350 | 100.000 | 99.650 | 0 | −0.350 | 0 / −0.01378 |
| 100 – 120 | 0 | −350 | 120.000 | 119.650 | 0 | −0.350 | 0 / −0.01378 |
| 120 – 140 | 0 | −400 | 140.000 | 139.600 | 0 | −0.400 | 0 / −0.01575 |
| 140 – 160 | 0 | −400 | 160.000 | 159.600 | 0 | −0.400 | 0 / −0.01575 |
| 160 – 180 | 0 | −400 | 180.000 | 179.600 | 0 | −0.400 | 0 / −0.01575 |
| 180 – 200 | 0 | −460 | 200.000 | 199.540 | 0 | −0.460 | 0 / −0.01811 |
| 200 – 225 | 0 | −460 | 225.000 | 224.540 | 0 | −0.460 | 0 / −0.01811 |
| 225 – 250 | 0 | −460 | 250.000 | 249.540 | 0 | −0.460 | 0 / −0.01811 |
| 250 – 280 | 0 | −520 | 280.000 | 279.480 | 0 | −0.520 | 0 / −0.02047 |
| 280 – 315 | 0 | −520 | 315.000 | 314.480 | 0 | −0.520 | 0 / −0.02047 |
| 315 – 355 | 0 | −570 | 355.000 | 354.430 | 0 | −0.570 | 0 / −0.02244 |
| 355 – 400 | 0 | −570 | 400.000 | 399.430 | 0 | −0.570 | 0 / −0.02244 |
| 400 – 450 | 0 | −630 | 450.000 | 449.370 | 0 | −0.630 | 0 / −0.02480 |
| 450 – 500 | 0 | −630 | 500.000 | 499.370 | 0 | −0.630 | 0 / −0.02480 |
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 h12
h12 denotes a shaft tolerance zone with zero line deviation in the ISO 286 system.
At Ø25 mm h12 is 0 / −0.210 mm, i.e. 24.790 to 25.000 mm.
How the limits are calculated
h12 uses grade IT12 (a standard tolerance of 210 µm at 18–30 mm). Fundamental deviation: es = 0: the tolerance zone sits entirely below the nominal size, and IT12 sets its width. See the fundamental deviation table for every letter. Values per ISO 286-1:2010.