---
type: "fit"
designation: "P7/h6"
hole: "P7"
shaft: "h6"
basis: "shaft"
classification: "interference"
role: "Locational interference, shaft basis."
size_count: 13
standard: "ISO 286-1:2010, ISO 286-2:2010"
verified: "August 1, 2026"
url: https://shopmath.org/fits/p7-h6
---

# P7/h6 Fit — ISO 286 Interference Fit Limits by Nominal Size

P7/h6 is a interference fit: at 25 mm nominal it gives 1 to 35 µm interference. Locational interference, shaft basis. The shaft is always larger than the hole — assembly needs force, heat or cold.

- **Designation**: P7/h6
- **Hole tolerance**: P7
- **Shaft tolerance**: h6
- **Basis**: shaft basis
- **Classification**: Interference fit
- **Typical use**: Locational interference, shaft basis.
- **Standard**: ISO 286-1:2010, ISO 286-2:2010

## P7/h6 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 | 4.980 | 4.992 | 4.992 | 5.000 | -20 | 0 | Interference |
| 6 mm | 5.980 | 5.992 | 5.992 | 6.000 | -20 | 0 | Interference |
| 8 mm | 7.976 | 7.991 | 7.991 | 8.000 | -24 | 0 | Interference |
| 10 mm | 9.976 | 9.991 | 9.991 | 10.000 | -24 | 0 | Interference |
| 12 mm | 11.971 | 11.989 | 11.989 | 12.000 | -29 | 0 | Interference |
| 16 mm | 15.971 | 15.989 | 15.989 | 16.000 | -29 | 0 | Interference |
| 20 mm | 19.965 | 19.986 | 19.987 | 20.000 | -35 | -1 | Interference |
| 25 mm | 24.965 | 24.986 | 24.987 | 25.000 | -35 | -1 | Interference |
| 30 mm | 29.965 | 29.986 | 29.987 | 30.000 | -35 | -1 | Interference |
| 40 mm | 39.958 | 39.983 | 39.984 | 40.000 | -42 | -1 | Interference |
| 50 mm | 49.958 | 49.983 | 49.984 | 50.000 | -42 | -1 | Interference |
| 80 mm | 79.949 | 79.979 | 79.981 | 80.000 | -51 | -2 | Interference |
| 100 mm | 99.941 | 99.976 | 99.978 | 100.000 | -59 | -2 | Interference |

## Fits Related to P7/h6

Fits that share the P7 hole or the h6 shaft — the alternatives to reach for when P7/h6 is too tight or too loose.

| Fit | Classification | Basis | Typical use |
| --- | --- | --- | --- |
| [G7/h6](https://shopmath.org/fits/g7-h6.md) | Clearance | shaft basis | Sliding, shaft basis. The h6 shaft is the reference and the hole carries the clearance. |
| [H7/h6](https://shopmath.org/fits/h7-h6.md) | Clearance | both basis | Locational clearance. Assembles by hand, no free movement intended. |
| [K7/h6](https://shopmath.org/fits/k7-h6.md) | Transition | shaft basis | Locational transition, shaft basis. |
| [N7/h6](https://shopmath.org/fits/n7-h6.md) | Transition | shaft basis | Tight transition, shaft basis. |

## Sources and Method for the P7/h6 Fit

### P7/h6 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 P7/h6 Fit

### What kind of fit is P7/h6?

P7/h6 is a interference fit on a shaft basis. The shaft is always larger than the hole — assembly needs force, heat or cold. Locational interference, shaft basis.

### What is the clearance on a 25 mm P7/h6 fit?

At 25 mm nominal, P7/h6 gives 1 to 35 µm interference. The hole runs 24.965 to 24.986 mm and the shaft 24.987 to 25.000 mm.

### What hole and shaft tolerances make up P7/h6?

P7/h6 pairs a P7 hole with a h6 shaft. On a shaft basis, the shaft carries the zero-deviation member and the other side is moved to set the fit.

## Related pages

- Hole tolerance: [P7 limits by size](https://shopmath.org/fits/p7.md)
- Shaft tolerance: [h6 limits by size](https://shopmath.org/fits/h6.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/p7-h6) — data verified August 1, 2026. Reference data; verify against the governing standard before manufacture.*