H11 hole tolerance (IT11)
Capital H11 is an ISO 286 hole tolerance class (IT11, EI = 0): at Ø10 mm the deviations are +0.090/0 mm, at Ø25 mm +0.130/0 mm (upper/lower). Looking for the h11 shaft?
Hole tolerance class H11 per ISO 286-1:2010: fundamental deviation EI = 0, grade IT11 (60 µm at ≤ 3 mm to 400 µm at 400–500 mm). For an exact size, open the calculator with H11 selected.
- Type
- Hole
- Grade
- IT11
- Tolerance
- 60 … 400 µm
- Fund. deviation
- EI = 0
H11 limits by size range
| Size (mm) | Upper (µm) | Lower (µm) | Ø max (mm) | Ø min (mm) | Upper (mm) | Lower (mm) | Dev. (in) |
|---|---|---|---|---|---|---|---|
| ≤ 3 | +60 | 0 | 3.060 | 3.000 | +0.060 | 0 | +0.00236 / 0 |
| 3 – 6 | +75 | 0 | 6.075 | 6.000 | +0.075 | 0 | +0.00295 / 0 |
| 6 – 10 | +90 | 0 | 10.090 | 10.000 | +0.090 | 0 | +0.00354 / 0 |
| 10 – 14 | +110 | 0 | 14.110 | 14.000 | +0.110 | 0 | +0.00433 / 0 |
| 14 – 18 | +110 | 0 | 18.110 | 18.000 | +0.110 | 0 | +0.00433 / 0 |
| 18 – 24 | +130 | 0 | 24.130 | 24.000 | +0.130 | 0 | +0.00512 / 0 |
| 24 – 30 | +130 | 0 | 30.130 | 30.000 | +0.130 | 0 | +0.00512 / 0 |
| 30 – 40 | +160 | 0 | 40.160 | 40.000 | +0.160 | 0 | +0.00630 / 0 |
| 40 – 50 | +160 | 0 | 50.160 | 50.000 | +0.160 | 0 | +0.00630 / 0 |
| 50 – 65 | +190 | 0 | 65.190 | 65.000 | +0.190 | 0 | +0.00748 / 0 |
| 65 – 80 | +190 | 0 | 80.190 | 80.000 | +0.190 | 0 | +0.00748 / 0 |
| 80 – 100 | +220 | 0 | 100.220 | 100.000 | +0.220 | 0 | +0.00866 / 0 |
| 100 – 120 | +220 | 0 | 120.220 | 120.000 | +0.220 | 0 | +0.00866 / 0 |
| 120 – 140 | +250 | 0 | 140.250 | 140.000 | +0.250 | 0 | +0.00984 / 0 |
| 140 – 160 | +250 | 0 | 160.250 | 160.000 | +0.250 | 0 | +0.00984 / 0 |
| 160 – 180 | +250 | 0 | 180.250 | 180.000 | +0.250 | 0 | +0.00984 / 0 |
| 180 – 200 | +290 | 0 | 200.290 | 200.000 | +0.290 | 0 | +0.01142 / 0 |
| 200 – 225 | +290 | 0 | 225.290 | 225.000 | +0.290 | 0 | +0.01142 / 0 |
| 225 – 250 | +290 | 0 | 250.290 | 250.000 | +0.290 | 0 | +0.01142 / 0 |
| 250 – 280 | +320 | 0 | 280.320 | 280.000 | +0.320 | 0 | +0.01260 / 0 |
| 280 – 315 | +320 | 0 | 315.320 | 315.000 | +0.320 | 0 | +0.01260 / 0 |
| 315 – 355 | +360 | 0 | 355.360 | 355.000 | +0.360 | 0 | +0.01417 / 0 |
| 355 – 400 | +360 | 0 | 400.360 | 400.000 | +0.360 | 0 | +0.01417 / 0 |
| 400 – 450 | +400 | 0 | 450.400 | 450.000 | +0.400 | 0 | +0.01575 / 0 |
| 450 – 500 | +400 | 0 | 500.400 | 500.000 | +0.400 | 0 | +0.01575 / 0 |
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 H11
H11 denotes a hole tolerance zone with zero line deviation in the ISO 286 system. It is used in H11/c11 (Large clearance for parts that must assemble easily despite dirt, heat or poor alignment: agricultural machinery, brake linkages, loose pulleys.) and H11/a11 (Maximum clearance in the standard series; used where parts run hot or where accuracy is irrelevant.).
At Ø25 mm H11 is +0.130 / 0 mm, i.e. 25.000 to 25.130 mm.
How the limits are calculated
H11 uses grade IT11 (a standard tolerance of 130 µm at 18–30 mm). Fundamental deviation: EI = 0: the tolerance zone sits entirely above the nominal size, and IT11 sets its width. See the fundamental deviation table for every letter. Values per ISO 286-1:2010.
H11 in practice
Where it's used
H11 is a coarse hole class for parts that only need to go together: holes for clevis and hinge pins, bores of loose pulleys and idler wheels, and levers and linkages on agricultural and construction machinery. Paired with c11, d11 or h11 shafts it gives the loose running and loose locational fits. IT11 is often within reach of a sharp twist drill, so many H11 holes need no reaming.
How to check it
A plug gauge is still the quickest go/no-go check. A digital caliper is usually adequate above about 10 mm; below that IT11 shrinks under 0.1 mm, and pin gauges are the better check. Measure past the entry burr: a drilled hole is often bell-mouthed at the top and tighter further in.
Easily confused with
h11 is the matching shaft class, with its zone below the nominal size; H11/h11 is a locational fit with zero minimum clearance, not a running fit. H11 is also not a general tolerance. ISO 2768 general tolerances are symmetric (±), while H11 is one-sided and entirely above the nominal size, so a pin of exactly the nominal diameter always enters.
Worked example
Clevis pins to ISO 2341 are made to h11. A Ø12 pin (11.890–12.000 mm) in a Ø12 H11 hole (12.000–12.110 mm, +0.110/0 mm) has 0.000–0.220 mm of play. Most pairs land mid-band, so the pin goes in easily even with paint or dirt in the joint.