a11 tolerance (shaft, IT11)
Shaft tolerance class a11 per ISO 286-1:2010: fundamental deviation es −270 … −1650, grade IT11 (60 µm at ≤ 3 mm to 400 µm at 400–500 mm). For an exact size, open the calculator with a11 selected.
- Type
- Shaft
- Grade
- IT11
- Tolerance
- 60 … 400 µm
- Fund. deviation
- es −270 … −1650 µm
a11 limits by size range
| Size (mm) | Upper (µm) | Lower (µm) | Ø max (mm) | Ø min (mm) | Upper (mm) | Lower (mm) | Dev. (in) |
|---|---|---|---|---|---|---|---|
| ≤ 3 | −270 | −330 | 2.730 | 2.670 | −0.270 | −0.330 | −0.01063 / −0.01299 |
| 3 – 6 | −270 | −345 | 5.730 | 5.655 | −0.270 | −0.345 | −0.01063 / −0.01358 |
| 6 – 10 | −280 | −370 | 9.720 | 9.630 | −0.280 | −0.370 | −0.01102 / −0.01457 |
| 10 – 14 | −290 | −400 | 13.710 | 13.600 | −0.290 | −0.400 | −0.01142 / −0.01575 |
| 14 – 18 | −290 | −400 | 17.710 | 17.600 | −0.290 | −0.400 | −0.01142 / −0.01575 |
| 18 – 24 | −300 | −430 | 23.700 | 23.570 | −0.300 | −0.430 | −0.01181 / −0.01693 |
| 24 – 30 | −300 | −430 | 29.700 | 29.570 | −0.300 | −0.430 | −0.01181 / −0.01693 |
| 30 – 40 | −310 | −470 | 39.690 | 39.530 | −0.310 | −0.470 | −0.01220 / −0.01850 |
| 40 – 50 | −320 | −480 | 49.680 | 49.520 | −0.320 | −0.480 | −0.01260 / −0.01890 |
| 50 – 65 | −340 | −530 | 64.660 | 64.470 | −0.340 | −0.530 | −0.01339 / −0.02087 |
| 65 – 80 | −360 | −550 | 79.640 | 79.450 | −0.360 | −0.550 | −0.01417 / −0.02165 |
| 80 – 100 | −380 | −600 | 99.620 | 99.400 | −0.380 | −0.600 | −0.01496 / −0.02362 |
| 100 – 120 | −410 | −630 | 119.590 | 119.370 | −0.410 | −0.630 | −0.01614 / −0.02480 |
| 120 – 140 | −460 | −710 | 139.540 | 139.290 | −0.460 | −0.710 | −0.01811 / −0.02795 |
| 140 – 160 | −520 | −770 | 159.480 | 159.230 | −0.520 | −0.770 | −0.02047 / −0.03031 |
| 160 – 180 | −580 | −830 | 179.420 | 179.170 | −0.580 | −0.830 | −0.02283 / −0.03268 |
| 180 – 200 | −660 | −950 | 199.340 | 199.050 | −0.660 | −0.950 | −0.02598 / −0.03740 |
| 200 – 225 | −740 | −1030 | 224.260 | 223.970 | −0.740 | −1.030 | −0.02913 / −0.04055 |
| 225 – 250 | −820 | −1110 | 249.180 | 248.890 | −0.820 | −1.110 | −0.03228 / −0.04370 |
| 250 – 280 | −920 | −1240 | 279.080 | 278.760 | −0.920 | −1.240 | −0.03622 / −0.04882 |
| 280 – 315 | −1050 | −1370 | 313.950 | 313.630 | −1.050 | −1.370 | −0.04134 / −0.05394 |
| 315 – 355 | −1200 | −1560 | 353.800 | 353.440 | −1.200 | −1.560 | −0.04724 / −0.06142 |
| 355 – 400 | −1350 | −1710 | 398.650 | 398.290 | −1.350 | −1.710 | −0.05315 / −0.06732 |
| 400 – 450 | −1500 | −1900 | 448.500 | 448.100 | −1.500 | −1.900 | −0.05906 / −0.07480 |
| 450 – 500 | −1650 | −2050 | 498.350 | 497.950 | −1.650 | −2.050 | −0.06496 / −0.08071 |
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 a11
a11 denotes a shaft tolerance zone with large clearance deviation in the ISO 286 system. It is used in H11/a11 (Maximum clearance in the standard series; used where parts run hot or where accuracy is irrelevant.).
At Ø25 mm a11 is −0.300 / −0.430 mm, i.e. 24.570 to 24.700 mm.
How the limits are calculated
a11 uses grade IT11 (a standard tolerance of 130 µm at 18–30 mm). Fundamental deviation: es is tabulated directly by ISO 286-1 Table 2; ei = es − IT11. See the fundamental deviation table for every letter. Values per ISO 286-1:2010.