Tolerance chart
h11 tolerance (shaft): ISO 286 chart up to 500 mm
h11 is an ISO tolerance class for shafts (external features) under ISO 286. At Ø25 mm it means 0 / −130 µm: the size may lie between 24.870 and 25.000 mm. Below are the deviations for every nominal size up to 500 mm and the fits that use h11.
h11 chart: deviations for all nominal sizes up to 500 mm
Deviations in µm (1 µm = 0.001 mm). A nominal size belongs to the row »over … up to and including …«: exactly 30 mm is in the row ending at 30, 30.1 mm in the next one.
| Nominal size over – to (mm) | Upper deviation | Lower deviation | Tolerance |
|---|---|---|---|
| 0 – 3 | 0 | −60 | 60 |
| 3 – 6 | 0 | −75 | 75 |
| 6 – 10 | 0 | −90 | 90 |
| 10 – 18 | 0 | −110 | 110 |
| 18 – 30 | 0 | −130 | 130 |
| 30 – 50 | 0 | −160 | 160 |
| 50 – 80 | 0 | −190 | 190 |
| 80 – 120 | 0 | −220 | 220 |
| 120 – 180 | 0 | −250 | 250 |
| 180 – 250 | 0 | −290 | 290 |
| 250 – 315 | 0 | −320 | 320 |
| 315 – 400 | 0 | −360 | 360 |
| 400 – 500 | 0 | −400 | 400 |
h11 for your nominal size
How h11 is built
An ISO tolerance class is a letter and a number. Capital letters stand for holes, small letters for shafts. The letter h sets the position of the tolerance zone; at Ø25 mm it lies from the nominal size downwards: the shaft is never larger than nominal. The number 11 is the standard tolerance grade IT11: it sets how wide the zone is – 130 µm at Ø25 mm.
The tolerance grows with the nominal size: 60 µm in the smallest row (0 – 3 mm), 400 µm in the largest (400 – 500 mm). On a drawing the class follows the dimension, as in »Ø25 h11«; the inspection plan turns that into the limits 24.870 and 25.000 mm.
Fits with h11 at Ø25 mm
Shaft-basis system: the shaft stays h11, the hole changes. Clearance in µm; a minus means interference. Sorted from the largest minimum clearance to the largest interference.
| Fit | Type | Max. clearance | Min. clearance |
|---|---|---|---|
| H11/h11 | clearance fit | 260 | 0 |
Frequently asked questions about h11
What does h11 mean?
h11 is an ISO tolerance class for shafts (external features): the letter h sets the position of the tolerance zone, the number 11 the standard tolerance grade IT11. At Ø25 mm that gives 0 / −130 µm, i.e. 24.870 to 25.000 mm.
What are the h11 limits at Ø10 and Ø50 mm?
Ø10 h11: 0 / −90 µm (9.910 to 10.000 mm). Ø50 h11: 0 / −160 µm (49.840 to 50.000 mm).
Is h11 a clearance fit?
A tolerance class on its own is not a fit – only together with its mating part. H11/h11 at Ø25 mm is a clearance fit (maximum clearance 260 µm, minimum clearance 0 µm; a minus means interference).
More tolerance classes
Same letter h, other grades: h5 · h6 · h7 · h8 · h9
All classes at a glance: ISO 286 tolerance charts. The same chart in German: h11 Toleranz.