---
type: "fit"
designation: "H11/c11"
hole: "H11"
shaft: "c11"
basis: "hole"
classification: "clearance"
role: "Loose running. Wide commercial tolerances, large clearance for dirt, paint and thermal growth."
size_count: 13
standard: "ISO 286-1:2010, ISO 286-2:2010"
verified: "August 1, 2026"
url: https://shopmath.org/fits/h11-c11
---

# H11/c11 Fit — ISO 286 Clearance Fit Limits by Nominal Size

H11/c11 is a clearance fit: at 25 mm nominal it gives 110 to 370 µm clearance. Loose running. Wide commercial tolerances, large clearance for dirt, paint and thermal growth. The hole is always larger than the shaft — the parts always assemble with a gap.

- **Designation**: H11/c11
- **Hole tolerance**: H11
- **Shaft tolerance**: c11
- **Basis**: hole basis
- **Classification**: Clearance fit
- **Typical use**: Loose running. Wide commercial tolerances, large clearance for dirt, paint and thermal growth.
- **Standard**: ISO 286-1:2010, ISO 286-2:2010

## H11/c11 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 | 5.075 | 4.855 | 4.930 | 70 | 220 | Clearance |
| 6 mm | 6.000 | 6.075 | 5.855 | 5.930 | 70 | 220 | Clearance |
| 8 mm | 8.000 | 8.090 | 7.830 | 7.920 | 80 | 260 | Clearance |
| 10 mm | 10.000 | 10.090 | 9.830 | 9.920 | 80 | 260 | Clearance |
| 12 mm | 12.000 | 12.110 | 11.795 | 11.905 | 95 | 315 | Clearance |
| 16 mm | 16.000 | 16.110 | 15.795 | 15.905 | 95 | 315 | Clearance |
| 20 mm | 20.000 | 20.130 | 19.760 | 19.890 | 110 | 370 | Clearance |
| 25 mm | 25.000 | 25.130 | 24.760 | 24.890 | 110 | 370 | Clearance |
| 30 mm | 30.000 | 30.130 | 29.760 | 29.890 | 110 | 370 | Clearance |
| 40 mm | 40.000 | 40.160 | 39.720 | 39.880 | 120 | 440 | Clearance |
| 50 mm | 50.000 | 50.160 | 49.710 | 49.870 | 130 | 450 | Clearance |
| 80 mm | 80.000 | 80.190 | 79.660 | 79.850 | 150 | 530 | Clearance |
| 100 mm | 100.000 | 100.220 | 99.610 | 99.830 | 170 | 610 | Clearance |

## Sources and Method for the H11/c11 Fit

### H11/c11 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 H11/c11 Fit

### What kind of fit is H11/c11?

H11/c11 is a clearance fit on a hole basis. The hole is always larger than the shaft — the parts always assemble with a gap. Loose running. Wide commercial tolerances, large clearance for dirt, paint and thermal growth.

### What is the clearance on a 25 mm H11/c11 fit?

At 25 mm nominal, H11/c11 gives 110 to 370 µm clearance. The hole runs 25.000 to 25.130 mm and the shaft 24.760 to 24.890 mm.

### What hole and shaft tolerances make up H11/c11?

H11/c11 pairs a H11 hole with a c11 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: [H11 limits by size](https://shopmath.org/fits/h11.md)
- Shaft tolerance: [c11 limits by size](https://shopmath.org/fits/c11.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/h11-c11) — data verified August 1, 2026. Reference data; verify against the governing standard before manufacture.*