Tolerance chart

R7 tolerance (hole): ISO 286 chart up to 500 mm

R7 is an ISO tolerance class for holes (internal features) under ISO 286. At Ø25 mm it means −20 / −41 µm: the size may lie between 24.959 and 24.980 mm. Below are the deviations for every nominal size up to 500 mm and the fits that use R7.

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

R7 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	−10	−20	10
3 – 6	−11	−23	12
6 – 10	−13	−28	15
10 – 18	−16	−34	18
18 – 30	−20	−41	21
30 – 50	−25	−50	25
50 – 65	−30	−60	30
65 – 80	−32	−62	30
80 – 100	−38	−73	35
100 – 120	−41	−76	35
120 – 140	−48	−88	40
140 – 160	−50	−90	40
160 – 180	−53	−93	40
180 – 200	−60	−106	46
200 – 225	−63	−109	46
225 – 250	−67	−113	46
250 – 280	−74	−126	52
280 – 315	−78	−130	52
315 – 355	−87	−144	57
355 – 400	−93	−150	57
400 – 450	−103	−166	63
450 – 500	−109	−172	63

R7 for your nominal size

How R7 is built

An ISO tolerance class is a letter and a number. Capital letters stand for holes, small letters for shafts. The letter R 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 (450 – 500 mm). On a drawing the class follows the dimension, as in »Ø25 R7«; the inspection plan turns that into the limits 24.959 and 24.980 mm.

Fits with R7 at Ø25 mm

Shaft-basis system: the shaft is h, the hole R7. Clearance in µm; a minus means interference. Sorted from the largest minimum clearance to the largest interference.

Fit	Type	Max. clearance	Min. clearance
R7/h6	interference fit	−7	−41
R7/h7	transition fit	1	−41

Frequently asked questions about R7

What does R7 mean?

R7 is an ISO tolerance class for holes (internal features): the letter R sets the position of the tolerance zone, the number 7 the standard tolerance grade IT7. At Ø25 mm that gives −20 / −41 µm, i.e. 24.959 to 24.980 mm.

What are the R7 limits at Ø10 and Ø50 mm?

Ø10 R7: −13 / −28 µm (9.972 to 9.987 mm). Ø50 R7: −25 / −50 µm (49.950 to 49.975 mm).

Is R7 a clearance fit?

A tolerance class on its own is not a fit – only together with its mating part. R7/h6 at Ø25 mm is a interference fit (maximum clearance −7 µm, minimum clearance −41 µm; a minus means interference).

More tolerance classes

Holes in grade 7: H7 · G7 · F7 · JS7 · K7 · M7 · N7 · P7 · S7

All classes at a glance: ISO 286 tolerance charts. The same chart in German: R7 Toleranz.