---
type: "fit-designation"
designation: "f7"
letter: "f"
it_grade: "ITIT7"
feature: "shaft"
role: "Close running shaft — the standard choice for lubricated journals at moderate speed."
size_count: 13
size_range_mm: "5–100"
standard: "ISO 286-1:2010, ISO 286-2:2010"
verified: "August 1, 2026"
url: https://shopmath.org/fits/f7
---

# f7 Tolerance — ISO 286 Shaft Limits by Nominal Size

A 25 mm f7 shaft runs 24.959 to 24.980 mm — deviations -41 to -20 µm on a 21 µm band. f7 is the ISO 286 shaft tolerance built from fundamental deviation f and standard tolerance grade ITIT7. Close running shaft — the standard choice for lubricated journals at moderate speed.

- **Designation**: f7
- **Feature**: shaft
- **Fundamental deviation**: f — Close running clearance
- **Tolerance grade**: ITIT7
- **Typical use**: Close running shaft — the standard choice for lubricated journals at moderate speed.
- **Standard**: ISO 286-1:2010, ISO 286-2:2010

## f7 Limits and Deviations by Nominal Size

Deviations are in micrometres from the nominal size; limits are the finished diameters in millimetres. Sizes that carry their own page are linked.

| Nominal size | Upper deviation (µm) | Lower deviation (µm) | Min shaft Ø (mm) | Max shaft Ø (mm) | IT tolerance (µm) |
| --- | --- | --- | --- | --- | --- |
| [5 mm](https://shopmath.org/fits/f7/5mm.md) | -10 | -22 | 4.978 | 4.990 | 12 |
| [6 mm](https://shopmath.org/fits/f7/6mm.md) | -10 | -22 | 5.978 | 5.990 | 12 |
| [8 mm](https://shopmath.org/fits/f7/8mm.md) | -13 | -28 | 7.972 | 7.987 | 15 |
| [10 mm](https://shopmath.org/fits/f7/10mm.md) | -13 | -28 | 9.972 | 9.987 | 15 |
| [12 mm](https://shopmath.org/fits/f7/12mm.md) | -16 | -34 | 11.966 | 11.984 | 18 |
| [16 mm](https://shopmath.org/fits/f7/16mm.md) | -16 | -34 | 15.966 | 15.984 | 18 |
| [20 mm](https://shopmath.org/fits/f7/20mm.md) | -20 | -41 | 19.959 | 19.980 | 21 |
| [25 mm](https://shopmath.org/fits/f7/25mm.md) | -20 | -41 | 24.959 | 24.980 | 21 |
| [30 mm](https://shopmath.org/fits/f7/30mm.md) | -20 | -41 | 29.959 | 29.980 | 21 |
| [40 mm](https://shopmath.org/fits/f7/40mm.md) | -25 | -50 | 39.950 | 39.975 | 25 |
| [50 mm](https://shopmath.org/fits/f7/50mm.md) | -25 | -50 | 49.950 | 49.975 | 25 |
| [80 mm](https://shopmath.org/fits/f7/80mm.md) | -30 | -60 | 79.940 | 79.970 | 30 |
| [100 mm](https://shopmath.org/fits/f7/100mm.md) | -36 | -71 | 99.929 | 99.964 | 35 |

_ISO 286 tabulates deviations per size band, so a value holds across the whole band a nominal size falls in, not just at that exact diameter._

## Sources and Method for f7

### f7 deviations

- **Source**: limits 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.
- 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 f7 Tolerance

### What is an f7 tolerance?

f7 is an ISO 286 shaft tolerance: fundamental deviation f at IT grade IT7. Close running shaft — the standard choice for lubricated journals at moderate speed. Close running clearance describes what the f deviation does.

### What is the tolerance on a 25 mm f7 shaft?

A 25 mm f7 shaft runs 24.959 to 24.980 mm — deviations -41 to -20 µm, a tolerance band of 21 µm.

## Fits Built on f7

Standard hole/shaft pairs that use f7 as their shaft.

| 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. |

## Related pages

- 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/f7) — data verified August 1, 2026. Reference data; verify against the governing standard before manufacture.*