ISO 286 · clearance fit · hole basis
H11/c11 Clearance Fit — Hole and Shaft Limits by Size
https://shopmath.org/fits/h11-c11 · data verified August 1, 2026
A 25 mm H11/c11 fit gives +110 to +370 µm of clearance — a 25.000–25.130 mm hole on a 24.760–24.890 mm shaft. 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. All values apply at 20 °C.
- Type
- clearance
- Hole
- H11
- Shaft
- c11
- Sizes
- 13
- Standard
- ISO 286-1:2010
H11/c11 at Ø25 mm · clearance, µm
+110 … +370
- Hole
- 25.000–25.130mm
- Shaft
- 24.760–24.890mm
Clearance at Ø25 mm, at 20 °C. Every other verified size is in the table below.
H11/c11 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.
| Property | Hole, mm | Shaft, mm | Clearance, µm | Property | |||
|---|---|---|---|---|---|---|---|
| Nominal Ø | Min | Max | Min | Max | Min | Max | At this size |
| 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 |
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 H11/c11 Fit
H11/c11 is H11 on the hole and c11 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.
Sources and Method for the H11/c11 Fit Data
- H11/c11 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 to Cite This H11/c11 Fit Reference
Citation
ShopMath. "H11/c11 Clearance Fit — Hole and Shaft Limits by Size." ShopMath, verified August 1, 2026, https://shopmath.org/fits/h11-c11
BibTeX
@misc{shopmath-fits-h11-c11,
title = {H11/c11 Clearance Fit — Hole and Shaft Limits by Size},
author = {{ShopMath}},
year = {2026},
howpublished = {\url{https://shopmath.org/fits/h11-c11}},
note = {Data verified 2026-08-01}
}Permanent URL
https://shopmath.org/fits/h11-c11
Common Questions About the H11/c11 Fit
What is the clearance of a 25 mm H11/c11 fit?
- A 25 mm H11/c11 fit has +110 to +370 µm of clearance: the hole runs 25.000 to 25.130 mm and the shaft 24.760 to 24.890 mm.
Is H11/c11 a clearance, transition or interference fit?
- H11/c11 is a clearance fit. 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 H11/c11 used for?
- Loose running. Wide commercial tolerances, large clearance for dirt, paint and thermal growth. 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 H11/c11 fit change with size?
- Across the 13 verified nominal sizes the clearance runs from +70 µm at 5 mm to +610 µm at 100 mm, because both tolerance bands widen with nominal size.