What is the clearance of a 25 mm H8/e8 fit?

A 25 mm H8/e8 fit has +40 to +106 µm of clearance: the hole runs 25.000 to 25.033 mm and the shaft 24.927 to 24.960 mm.

What is H8/e8 used for?

Running fit with room for a lubricant film at speed. It is a hole-basis fit, so the hole is held to one standard tolerance and the shaft is machined to suit.

How does the H8/e8 fit change with size?

Across the 13 verified nominal sizes the clearance runs from +20 µm at 5 mm to +180 µm at 100 mm, because both tolerance bands widen with nominal size.

ISO 286 · clearance fit · hole basis

H8/e8 Clearance Fit — Hole and Shaft Limits by Size

https://shopmath.org/fits/h8-e8 · data verified August 1, 2026

A 25 mm H8/e8 fit gives +40 to +106 µm of clearance — a 25.000–25.033 mm hole on a 24.927–24.960 mm shaft. Running fit with room for a lubricant film at speed. The hole is always larger than the shaft — the parts always assemble with a gap. All values apply at 20 °C.

Type: clearance
Hole: H8
Shaft: e8
Sizes: 13
Standard: ISO 286-1:2010

H8/e8 at Ø25 mm · clearance, µm

+40 … +106

Hole: 25.000–25.033mm
Shaft: 24.927–24.960mm

Clearance at Ø25 mm, at 20 °C. Every other verified size is in the table below.

H8/e8 Fit — Hole and Shaft Limits with Clearance, by Nominal Size

Both parts' limits in millimetres and the resulting clearance in micrometres. Negative clearance is interference: the shaft is larger than the hole and the joint needs force, heat or cold to assemble.

H8/e8 fit — hole limits, shaft limits and clearance by nominal size
Property	Hole, mm		Shaft, mm		Clearance, µm		Property
Nominal Ø	Min	Max	Min	Max	Min	Max	At this size
5 mm	5.000	5.018	4.962	4.980	+20	+56	clearance
6 mm	6.000	6.018	5.962	5.980	+20	+56	clearance
8 mm	8.000	8.022	7.953	7.975	+25	+69	clearance
10 mm	10.000	10.022	9.953	9.975	+25	+69	clearance
12 mm	12.000	12.027	11.941	11.968	+32	+86	clearance
16 mm	16.000	16.027	15.941	15.968	+32	+86	clearance
20 mm	20.000	20.033	19.927	19.960	+40	+106	clearance
25 mm	25.000	25.033	24.927	24.960	+40	+106	clearance
30 mm	30.000	30.033	29.927	29.960	+40	+106	clearance
40 mm	40.000	40.039	39.911	39.950	+50	+128	clearance
50 mm	50.000	50.039	49.911	49.950	+50	+128	clearance
80 mm	80.000	80.046	79.894	79.940	+60	+152	clearance
100 mm	100.000	100.054	99.874	99.928	+72	+180	clearance

Minimum clearance is the largest shaft in the smallest hole; maximum clearance is the smallest shaft in the largest hole. Values apply at the ISO 286 reference temperature of 20 °C.

The Hole and Shaft Tolerances That Make the H8/e8 Fit

H8/e8 is H8 on the hole and e8 on the shaft. It is a hole-basis fit: the hole is held to one standard tolerance and the shaft is varied to change the fit — which is what you want when the hole is reamed or bored to a standard size.

Hole
H8 →
Basic hole where a close running fit is wanted but H7 is more precision than the job needs.
Shaft
e8 →
Running shaft with generous clearance for lubrication at speed.

Fits That Share a Tolerance With the H8/e8 Fit

Changing one half of the pair is how a design moves from clearance to interference. These fits keep H8 or e8 and change the other side.

ISO 286 fits sharing a hole or shaft tolerance with H8/e8
Fit	Type	What it is for
H8/f7	clearance	Close running. The general-purpose lubricated journal fit.

Ordered loosest to tightest within each type.

Sources and Method for the H8/e8 Fit Data

H8/e8 limitscomputed

computed from the compiled ISO 286 tables: ISO 286-1 IT grades and ISO 286-2 fundamental deviations, compiled from saucecode/ISO286 (LGPL-2.1) and parkergreene/isofits (MIT), cross-checked cell-for-cell

Verified against parkergreene/isofits ISO 286-2 limit tables (MIT); ISO 286-1 formula harness — 2067 checks passed

Computed from the standard's formulas, then checked against published tables.

Formula

Clearance from the two tolerance bands

max clearance  =  hole max − shaft min
min clearance  =  hole min − shaft max

A negative result is interference. Both are computed from the compiled ISO 286-2 deviations, not from the ISO 286-1 formula, which deviates from the published table by up to 13%.

Assumptions

Values apply at the ISO 286 reference temperature of 20 °C. A joint assembled hot or cold, or running hot, is not at these limits.
The tolerances cover size only. Form, roundness, cylindricity and surface finish all affect how a fit behaves and need their own callouts.
Dataset scope: COMPILED not computed: the ISO 286-1 formula deviates up to 13.26% from the table and is used only as a harness (warn >5%, fail >15%). EXCLUDED: shaft/hole letters s, t, u and the fits H7/s6, H7/t6, H7/u6 — no free source and an undetermined step constant in the formula.

Data last verified

August 1, 2026

How this data is built and checked →

How to Cite This H8/e8 Fit Reference

Citation

ShopMath. "H8/e8 Clearance Fit — Hole and Shaft Limits by Size." ShopMath, verified August 1, 2026, https://shopmath.org/fits/h8-e8

BibTeX

@misc{shopmath-fits-h8-e8,
  title        = {H8/e8 Clearance Fit — Hole and Shaft Limits by Size},
  author       = {{ShopMath}},
  year         = {2026},
  howpublished = {\url{https://shopmath.org/fits/h8-e8}},
  note         = {Data verified 2026-08-01}
}

Permanent URL

https://shopmath.org/fits/h8-e8

Common Questions About the H8/e8 Fit

What is the clearance of a 25 mm H8/e8 fit?: A 25 mm H8/e8 fit has +40 to +106 µm of clearance: the hole runs 25.000 to 25.033 mm and the shaft 24.927 to 24.960 mm.
Is H8/e8 a clearance, transition or interference fit?: H8/e8 is a clearance fit. The hole is always larger than the shaft — the parts always assemble with a gap. Running fit with room for a lubricant film at speed.
What is H8/e8 used for?: Running fit with room for a lubricant film at speed. It is a hole-basis fit, so the hole is held to one standard tolerance and the shaft is machined to suit.
How does the H8/e8 fit change with size?: Across the 13 verified nominal sizes the clearance runs from +20 µm at 5 mm to +180 µm at 100 mm, because both tolerance bands widen with nominal size.

Every ISO 286 designation and fit · ISO 286 tolerance chart