Tolerance chart

S7 tolerance (hole): ISO 286 chart up to 500 mm

S7 is an ISO tolerance class for holes (internal features) under ISO 286. At Ø25 mm it means −27 / −48 µm: the size may lie between 24.952 and 24.973 mm. Below are the deviations for every nominal size up to 500 mm and the fits that use S7.

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

S7 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	−14	−24	10
3 – 6	−15	−27	12
6 – 10	−17	−32	15
10 – 18	−21	−39	18
18 – 30	−27	−48	21
30 – 50	−34	−59	25
50 – 65	−42	−72	30
65 – 80	−48	−78	30
80 – 100	−58	−93	35
100 – 120	−66	−101	35
120 – 140	−77	−117	40
140 – 160	−85	−125	40
160 – 180	−93	−133	40
180 – 200	−105	−151	46
200 – 225	−113	−159	46
225 – 250	−123	−169	46
250 – 280	−138	−190	52
280 – 315	−150	−202	52
315 – 355	−169	−226	57
355 – 400	−187	−244	57
400 – 450	−209	−272	63
450 – 500	−229	−292	63

S7 for your nominal size

How S7 is built

An ISO tolerance class is a letter and a number. Capital letters stand for holes, small letters for shafts. The letter S 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 S7«; the inspection plan turns that into the limits 24.952 and 24.973 mm.

Fits with S7 at Ø25 mm

Shaft-basis system: the shaft is h, the hole S7. Clearance in µm; a minus means interference. Sorted from the largest minimum clearance to the largest interference.

Fit	Type	Max. clearance	Min. clearance
S7/h6	interference fit	−14	−48
S7/h7	interference fit	−6	−48

Frequently asked questions about S7

What does S7 mean?

S7 is an ISO tolerance class for holes (internal features): the letter S sets the position of the tolerance zone, the number 7 the standard tolerance grade IT7. At Ø25 mm that gives −27 / −48 µm, i.e. 24.952 to 24.973 mm.

What are the S7 limits at Ø10 and Ø50 mm?

Ø10 S7: −17 / −32 µm (9.968 to 9.983 mm). Ø50 S7: −34 / −59 µm (49.941 to 49.966 mm).

Is S7 a clearance fit?

A tolerance class on its own is not a fit – only together with its mating part. S7/h6 at Ø25 mm is a interference fit (maximum clearance −14 µm, minimum clearance −48 µm; a minus means interference).

More tolerance classes

Holes in grade 7: H7 · G7 · F7 · JS7 · K7 · M7 · N7 · P7 · R7

All classes at a glance: ISO 286 tolerance charts. The same chart in German: S7 Toleranz.