---
type: "fit"
designation: "H8/e8"
hole: "H8"
shaft: "e8"
basis: "hole"
classification: "clearance"
role: "Running fit with room for a lubricant film at speed."
size_count: 13
standard: "ISO 286-1:2010, ISO 286-2:2010"
verified: "August 1, 2026"
url: https://shopmath.org/fits/h8-e8
---

# H8/e8 Fit — ISO 286 Clearance Fit Limits by Nominal Size

H8/e8 is a clearance fit: at 25 mm nominal it gives 40 to 106 µm clearance. 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.

- **Designation**: H8/e8
- **Hole tolerance**: H8
- **Shaft tolerance**: e8
- **Basis**: hole basis
- **Classification**: Clearance fit
- **Typical use**: Running fit with room for a lubricant film at speed.
- **Standard**: ISO 286-1:2010, ISO 286-2:2010

## H8/e8 Hole and Shaft Limits by Nominal Size

Limits in millimetres, clearances in micrometres. A negative clearance is interference — the shaft is larger than the hole and assembly needs force, heat or cold.

| Nominal size | Hole min (mm) | Hole max (mm) | Shaft min (mm) | Shaft max (mm) | Min clearance (µm) | Max clearance (µm) | Result |
| --- | --- | --- | --- | --- | --- | --- | --- |
| 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 |

## Fits Related to H8/e8

Fits that share the H8 hole or the e8 shaft — the alternatives to reach for when H8/e8 is too tight or too loose.

| Fit | Classification | Basis | Typical use |
| --- | --- | --- | --- |
| [H8/f7](https://shopmath.org/fits/h8-f7.md) | Clearance | hole basis | Close running. The general-purpose lubricated journal fit. |

## Sources and Method for the H8/e8 Fit

### H8/e8 limits

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

### Assumptions

- Values are the ISO 286-2 tabulated limits, not the ISO 286-1 formula: the formula deviates from the table by up to 13.26% and is carried only as a validation harness.
- Limits are at 20 °C, the ISO 1 reference temperature. Clearance is the assembled gap before any thermal or load effect.
- 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

## Common Questions About the H8/e8 Fit

### What kind of fit is H8/e8?

H8/e8 is a clearance fit on a hole basis. 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 the clearance on a 25 mm H8/e8 fit?

At 25 mm nominal, H8/e8 gives 40 to 106 µm clearance. The hole runs 25.000 to 25.033 mm and the shaft 24.927 to 24.960 mm.

### What hole and shaft tolerances make up H8/e8?

H8/e8 pairs a H8 hole with a e8 shaft. On a hole basis, the hole carries the zero-deviation member and the other side is moved to set the fit.

## Related pages

- Hole tolerance: [H8 limits by size](https://shopmath.org/fits/h8.md)
- Shaft tolerance: [e8 limits by size](https://shopmath.org/fits/e8.md)
- All fits and tolerances: [ISO 286 fit reference](https://shopmath.org/fits.md)
- Full grade table: [ISO 286 tolerance chart](https://shopmath.org/charts/iso-tolerances.md)

---

*Source: [ShopMath](https://shopmath.org/fits/h8-e8) — data verified August 1, 2026. Reference data; verify against the governing standard before manufacture.*