Tolerance chart

P7 tolerance (hole): ISO 286 chart up to 500 mm

P7 is an ISO tolerance class for holes (internal features) under ISO 286. At Ø25 mm it means −14 / −35 µm: the size may lie between 24.965 and 24.986 mm. Below are the deviations for every nominal size up to 500 mm and the fits that use P7.

Updated 2026-10-30 · Basis: ISO 286-1:2010 and ISO 286-2:2010 · irot Erstmuster

P7 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	−16	10
3 – 6	−8	−20	12
6 – 10	−9	−24	15
10 – 18	−11	−29	18
18 – 30	−14	−35	21
30 – 50	−17	−42	25
50 – 80	−21	−51	30
80 – 120	−24	−59	35
120 – 180	−28	−68	40
180 – 250	−33	−79	46
250 – 315	−36	−88	52
315 – 400	−41	−98	57
400 – 500	−45	−108	63

P7 for your nominal size

How P7 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 7 is the standard tolerance grade IT7: it sets how wide the zone is – 21 µm at Ø25 mm.

The tolerance grows with the nominal size: 10 µm in the smallest row (0 – 3 mm), 63 µm in the largest (400 – 500 mm). On a drawing the class follows the dimension, as in »Ø25 P7«; the inspection plan turns that into the limits 24.965 and 24.986 mm.

Fits with P7 at Ø25 mm

Shaft-basis system: the shaft is h, the hole P7. Clearance in µm; a minus means interference. Sorted from the largest minimum clearance to the largest interference.

Fit	Type	Max. clearance	Min. clearance
P7/h6	interference fit	−1	−35
P7/h7	transition fit	7	−35

Frequently asked questions about P7

What does P7 mean?

P7 is an ISO tolerance class for holes (internal features): the letter P sets the position of the tolerance zone, the number 7 the standard tolerance grade IT7. At Ø25 mm that gives −14 / −35 µm, i.e. 24.965 to 24.986 mm.

What are the P7 limits at Ø10 and Ø50 mm?

Ø10 P7: −9 / −24 µm (9.976 to 9.991 mm). Ø50 P7: −17 / −42 µm (49.958 to 49.983 mm).

Is P7 a clearance fit?

A tolerance class on its own is not a fit – only together with its mating part. P7/h6 at Ø25 mm is a interference fit (maximum clearance −1 µm, minimum clearance −35 µm; a minus means interference).

More tolerance classes

Same letter P, other grades: P6

Holes in grade 7: H7 · G7 · F7 · JS7 · K7 · M7 · N7 · R7 · S7

All classes at a glance: ISO 286 tolerance charts. The same chart in German: P7 Toleranz.