Tolerance chart

e8 tolerance (shaft): ISO 286 chart up to 500 mm

e8 is an ISO tolerance class for shafts (external features) under ISO 286. At Ø25 mm it means −40 / −73 µm: the size may lie between 24.927 and 24.960 mm. Below are the deviations for every nominal size up to 500 mm and the fits that use e8.

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

e8 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	−28	14
3 – 6	−20	−38	18
6 – 10	−25	−47	22
10 – 18	−32	−59	27
18 – 30	−40	−73	33
30 – 50	−50	−89	39
50 – 80	−60	−106	46
80 – 120	−72	−126	54
120 – 180	−85	−148	63
180 – 250	−100	−172	72
250 – 315	−110	−191	81
315 – 400	−125	−214	89
400 – 500	−135	−232	97

e8 for your nominal size

How e8 is built

An ISO tolerance class is a letter and a number. Capital letters stand for holes, small letters for shafts. The letter e sets the position of the tolerance zone; at Ø25 mm it lies entirely below the nominal size: the shaft is always smaller than nominal. The number 8 is the standard tolerance grade IT8: it sets how wide the zone is – 33 µm at Ø25 mm.

The tolerance grows with the nominal size: 14 µm in the smallest row (0 – 3 mm), 97 µm in the largest (400 – 500 mm). On a drawing the class follows the dimension, as in »Ø25 e8«; the inspection plan turns that into the limits 24.927 and 24.960 mm.

Fits with e8 at Ø25 mm

Hole-basis system: the hole is H, the shaft e8. Clearance in µm; a minus means interference. Sorted from the largest minimum clearance to the largest interference.

Fit	Type	Max. clearance	Min. clearance
H8/e8	clearance fit	106	40
H9/e8	clearance fit	125	40

Frequently asked questions about e8

What does e8 mean?

e8 is an ISO tolerance class for shafts (external features): the letter e sets the position of the tolerance zone, the number 8 the standard tolerance grade IT8. At Ø25 mm that gives −40 / −73 µm, i.e. 24.927 to 24.960 mm.

What are the e8 limits at Ø10 and Ø50 mm?

Ø10 e8: −25 / −47 µm (9.953 to 9.975 mm). Ø50 e8: −50 / −89 µm (49.911 to 49.950 mm).

Is e8 a clearance fit?

A tolerance class on its own is not a fit – only together with its mating part. H9/e8 at Ø25 mm is a clearance fit (maximum clearance 125 µm, minimum clearance 40 µm; a minus means interference).

More tolerance classes

Same letter e, other grades: e7

Shafts in grade 8: h8

All classes at a glance: ISO 286 tolerance charts. The same chart in German: e8 Toleranz.