Tolerance chart
P6 tolerance (hole): ISO 286 chart up to 500 mm
P6 is an ISO tolerance class for holes (internal features) under ISO 286. At Ø25 mm it means −18 / −31 µm: the size may lie between 24.969 and 24.982 mm. Below are the deviations for every nominal size up to 500 mm and the fits that use P6.
P6 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 | −6 | −12 | 6 |
| 3 – 6 | −9 | −17 | 8 |
| 6 – 10 | −12 | −21 | 9 |
| 10 – 18 | −15 | −26 | 11 |
| 18 – 30 | −18 | −31 | 13 |
| 30 – 50 | −21 | −37 | 16 |
| 50 – 80 | −26 | −45 | 19 |
| 80 – 120 | −30 | −52 | 22 |
| 120 – 180 | −36 | −61 | 25 |
| 180 – 250 | −41 | −70 | 29 |
| 250 – 315 | −47 | −79 | 32 |
| 315 – 400 | −51 | −87 | 36 |
| 400 – 500 | −55 | −95 | 40 |
P6 for your nominal size
How P6 is built
An ISO tolerance class is a letter and a number. Capital letters stand for holes, small letters for shafts. The letter P sets the position of the tolerance zone; at Ø25 mm it lies entirely below the nominal size: the hole is always smaller than nominal. The number 6 is the standard tolerance grade IT6: it sets how wide the zone is – 13 µm at Ø25 mm.
The tolerance grows with the nominal size: 6 µm in the smallest row (0 – 3 mm), 40 µm in the largest (400 – 500 mm). On a drawing the class follows the dimension, as in »Ø25 P6«; the inspection plan turns that into the limits 24.969 and 24.982 mm.
Fits with P6 at Ø25 mm
Shaft-basis system: the shaft is h, the hole P6. Clearance in µm; a minus means interference. Sorted from the largest minimum clearance to the largest interference.
Frequently asked questions about P6
What does P6 mean?
P6 is an ISO tolerance class for holes (internal features): the letter P sets the position of the tolerance zone, the number 6 the standard tolerance grade IT6. At Ø25 mm that gives −18 / −31 µm, i.e. 24.969 to 24.982 mm.
What are the P6 limits at Ø10 and Ø50 mm?
Ø10 P6: −12 / −21 µm (9.979 to 9.988 mm). Ø50 P6: −21 / −37 µm (49.963 to 49.979 mm).
Is P6 a clearance fit?
A tolerance class on its own is not a fit – only together with its mating part. P6/h5 at Ø25 mm is a interference fit (maximum clearance −9 µm, minimum clearance −31 µm; a minus means interference).
More tolerance classes
Same letter P, other grades: P7
Holes in grade 6: H6 · G6 · JS6 · K6 · M6 · N6
All classes at a glance: ISO 286 tolerance charts. The same chart in German: P6 Toleranz.