What is the tolerance of a 25 mm h11 shaft?

A 25 mm h11 shaft runs 24.870 to 25.000 mm — deviations of -130 to 0 µm, a tolerance band 130 µm wide.

h11 is an ISO 286 shaft tolerance. The h sets the fundamental deviation — zero deviation — the basic shaft — and the 11 is the IT11 tolerance grade, which sets how wide the band is. Wide-tolerance basic shaft matching drawn or cold-finished bar.

How wide is the IT11 tolerance band?

IT11 is 130 µm wide for nominal sizes over 18 up to 30 mm, and widens with size — the full band table is on this page.

ISO 286 · shaft tolerance · IT11

h11 Tolerance — Shaft Limits by Nominal Size

https://shopmath.org/fits/h11-shaft · data verified August 1, 2026

A 25 mm h11 shaft runs 24.870 to 25.000 mm — deviations of -130 to 0 µm on a tolerance band 130 µm wide. The h sets where the band sits (zero deviation — the basic shaft) and IT11 sets how wide it is. Wide-tolerance basic shaft matching drawn or cold-finished bar. All values apply at 20 °C.

Feature: shaft
Letter: h
Grade: IT11
Sizes: 13
Standard: ISO 286-1:2010

h11 shaft at Ø25 mm · deviation, µm

0 / -130

Max Ø: 25.000mm
Min Ø: 24.870mm
Band: 130µm

Deviations from the 25 mm nominal size, at 20 °C. Every other verified size is in the table below.

Source: ISO 286-1:2010, ISO 286-2:2010
Formula: max Ø = nominal + es min Ø = nominal + ei
Assumptions: Ø25 mm nominal, 18–30 mm size step, plain cylindrical feature, 20 °C. Deviations are tabulated in the standard and compiled here; the limits are those deviations added to the nominal size.
Verified: August 1, 2026

h11 Shaft Limits at Every Verified Nominal Size

Deviations in micrometres and finished limits in millimetres. These are the thirteen nominal sizes with verified demand; the deviation pattern continues across the full ISO 286 size range.

h11 shaft tolerance — deviations and limits by nominal size
Property	Deviation, µm		Limits, mm		Property
Nominal Ø	Upper	Lower	Min	Max	Tolerance band, µm
5 mm	0	-75	4.925	5.000	75
6 mm	0	-75	5.925	6.000	75
8 mm	0	-90	7.910	8.000	90
10 mm	0	-90	9.910	10.000	90
12 mm	0	-110	11.890	12.000	110
16 mm	0	-110	15.890	16.000	110
20 mm	0	-130	19.870	20.000	130
25 mm	0	-130	24.870	25.000	130
30 mm	0	-130	29.870	30.000	130
40 mm	0	-160	39.840	40.000	160
50 mm	0	-160	49.840	50.000	160
80 mm	0	-190	79.810	80.000	190
100 mm	0	-220	99.780	100.000	220

Deviations are relative to the nominal size: positive is above it, negative below. Limits assume the ISO 286 reference temperature of 20 °C.

The IT11 Tolerance Grade in h11, Across ISO 286 Size Bands

The number in h11 is the IT grade, and it sets how wide the tolerance band is. The band widens with size — that is the whole point of a graded tolerance system.

IT11 standard tolerance by nominal size band
Nominal size band	Tolerance, µm	Tolerance, mm
over 0 to 3 mm	60	0.060
over 3 to 6 mm	75	0.075
over 6 to 10 mm	90	0.090
over 10 to 18 mm	110	0.110
over 18 to 30 mm	130	0.130
over 30 to 50 mm	160	0.160
over 50 to 80 mm	190	0.190
over 80 to 120 mm	220	0.220
over 120 to 180 mm	250	0.250
over 180 to 250 mm	290	0.290
over 250 to 315 mm	320	0.320
over 315 to 400 mm	360	0.360
over 400 to 500 mm	400	0.400

Bands are open at the bottom and closed at the top: 'over 18 to 30 mm' includes 30 mm and excludes 18 mm.

Fundamental Deviation of the h shaft Tolerance in h11

The letter in h11 sets where the tolerance band sits relative to the nominal size: zero deviation — the basic shaft. The grade then adds the band width to that starting point.

h fundamental deviation

0µm

At every one of the 25 ISO 286 size bands, from 0 to 500 mm.

The h deviation does not change with size — it is the upper limit (es / ES) for every band, so IT11 alone decides how wide the band is. That is what makes h11 the basic shaft: one limit is pinned at the nominal size and the grade opens the other. Sizes are given in the limits table above, and the full band-by-band listing is in this page’s Markdown twin.

Sources and Method for the h11 Tolerance Data

h11 limitscomputed

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

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.

IT11 tolerance gradecompiled

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. Formula per ISO 286-1 standard tolerance factor and fundamental deviation formulas, used as a validation harness only per docs/research/data-sourcing.md §3.6

Compiled from independent public sources that agree cell-for-cell.

h fundamental deviationcompiled

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

Compiled from independent public sources that agree cell-for-cell.

Formula

Limits from the deviations, shaft tolerance

max Ø  =  nominal + es
min Ø  =  nominal + ei

  es = upper deviation (µm)
  ei = lower deviation (µm)

The deviations are tabulated in ISO 286-2 and compiled here; the limits are those deviations added to the nominal size, which is why both columns are shown.

Assumptions

Values apply at the ISO 286 reference temperature of 20 °C.
Limits are for a plain cylindrical feature. A tolerance letter says nothing about surface finish, form or roundness — those 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 this data is built and checked →

How to Cite This h11 Tolerance Reference

Citation

ShopMath. "h11 Tolerance — Shaft Limits by Nominal Size." ShopMath, verified August 1, 2026, https://shopmath.org/fits/h11-shaft

BibTeX

@misc{shopmath-fits-h11-shaft,
  title        = {h11 Tolerance — Shaft Limits by Nominal Size},
  author       = {{ShopMath}},
  year         = {2026},
  howpublished = {\url{https://shopmath.org/fits/h11-shaft}},
  note         = {Data verified 2026-08-01}
}

Permanent URL

https://shopmath.org/fits/h11-shaft

Common Questions About the h11 Tolerance

What is the tolerance of a 25 mm h11 shaft?: A 25 mm h11 shaft runs 24.870 to 25.000 mm — deviations of -130 to 0 µm, a tolerance band 130 µm wide.
What does h11 mean?: h11 is an ISO 286 shaft tolerance. The h sets the fundamental deviation — zero deviation — the basic shaft — and the 11 is the IT11 tolerance grade, which sets how wide the band is. Wide-tolerance basic shaft matching drawn or cold-finished bar.
How wide is the IT11 tolerance band?: IT11 is 130 µm wide for nominal sizes over 18 up to 30 mm, and widens with size — the full band table is on this page.

Every ISO 286 designation and fit · ISO 286 tolerance chart