What is the tolerance for a 12 mm f7 shaft?

A 12 mm f7 shaft runs 11.966 to 11.984 mm — deviations of -34 to -16 µm, a band 18 µm wide.

What is the maximum and minimum size of a 12 mm f7 shaft?

Maximum 11.984 mm, minimum 11.966 mm. Anything outside that band is a reject at 20 °C, not a judgement call.

Why is the IT7 band 18 µm at 12 mm?

Because 12 mm falls in the ISO 286 size band over 10 up to 18 mm, and IT7 is defined per band rather than per size. Every nominal size in that band carries the same 18 µm width for IT7.

What shaft goes in a 12 mm f7 hole?

At 12 mm the standard pairs run from H7/h6 (0 to +29 µm clearance) through transition to interference fits — the full list with clearances is on this page.

What does the f in f7 mean?

Close running clearance. It fixes the fundamental deviation — the limit nearest the nominal size — while IT7 fixes the width of the band, which at 12 mm is 18 µm.

ISO 286 · f7 shaft · Ø12 mm

12 mm f7 Tolerance — Shaft Limits in mm and µm

https://shopmath.org/fits/f7/12mm · data verified August 1, 2026

A 12 mm f7 shaft is 11.966 to 11.984 mm — deviations of -34 to -16 µm on an IT7 band 18 µm wide. Close running shaft — the standard choice for lubricated journals at moderate speed. Values apply at the ISO 286 reference temperature of 20 °C.

Nominal: 12 mm
Designation: f7
Feature: shaft
Grade: IT7
Band: 18 µm

12 mm f7 shaft · limits, mm

11.966 … 11.984

Upper dev: -16µm
Lower dev: -34µm
Band: 18µm

Measured at 20 °C on a plain cylindrical feature. The IT7 grade sets the 18 µm width; the f sets where the band sits.

Limits for a 12 mm f7 Shaft

Deviations in micrometres, finished limits in millimetres. Both describe the same band — the deviation is what a drawing carries, the limit is what a gauge reads.

12 mm f7 shaft tolerance — deviations and limits
Limit	µm	mm
Upper deviation	-16	-0.016
Lower deviation	-34	-0.034
Maximum diameter	-16	11.984
Minimum diameter	-34	11.966
Tolerance band (IT7)	18	0.018

Deviations are relative to the 12 mm nominal size. Values apply at the ISO 286 reference temperature of 20 °C; a part measured warm is not at these limits.

ISO 286 Tolerance Grades at 12 mm

12 mm falls in the ISO 286 size band over 10 to 18 mm, so every tolerance in that band has the same width regardless of which letter it carries.

ISO 286 standard tolerance grades at 12 mm nominal size
Grade	Tolerance, µm	Tolerance, mm
IT5	8	0.008
IT6	11	0.011
IT7	18	0.018
IT8	27	0.027
IT9	43	0.043
IT10	70	0.070
IT11	110	0.110
IT12	180	0.180

The grade sets the width of the band; the letter sets where that band sits relative to the nominal size.

Every Other ISO 286 Tolerance at 12 mm

The same nominal size under every other designation in this reference — the comparison that decides whether a feature is called out f7 or something looser.

ISO 286 hole and shaft tolerances at 12 mm nominal size
Property	Property	Deviation, µm		Limits, mm
Designation	Applies to	Upper	Lower	Min	Max
c11	shaft	-95	-205	11.795	11.905
d9	shaft	-50	-93	11.907	11.950
e8	shaft	-32	-59	11.941	11.968
f7	shaft	-16	-34	11.966	11.984
g6	shaft	-6	-17	11.983	11.994
h11	shaft	0	-110	11.890	12.000
h6	shaft	0	-11	11.989	12.000
h7	shaft	0	-18	11.982	12.000
h9	shaft	0	-43	11.957	12.000
k6	shaft	+12	+1	12.001	12.012
m6	shaft	+18	+7	12.007	12.018
n6	shaft	+23	+12	12.012	12.023
p6	shaft	+29	+18	12.018	12.029
r6	shaft	+34	+23	12.023	12.034
F8	hole	+43	+16	12.016	12.043
G7	hole	+24	+6	12.006	12.024
H11	hole	+110	0	12.000	12.110
H6	hole	+11	0	12.000	12.011
H7	hole	+18	0	12.000	12.018
H8	hole	+27	0	12.000	12.027
H9	hole	+43	0	12.000	12.043
K7	hole	+6	-12	11.988	12.006
N7	hole	-5	-23	11.977	11.995
P7	hole	-11	-29	11.971	11.989

Links go to that designation's page for this size where one exists, and to its full size table otherwise.

Standard Fits Available at 12 mm

What each standard hole/shaft pair gives at 12 mm, loosest first. Negative clearance is interference.

ISO 286 fits and their clearance at 12 mm nominal size
Property	Property	Clearance, µm		Property
Fit	Type	Min	Max	What it is for
H7/h6	clearance	0	+29	Locational clearance. Assembles by hand, no free movement intended.
H11/c11	clearance	+95	+315	Loose running. Wide commercial tolerances, large clearance for dirt, paint and thermal growth.
H9/d9	clearance	+50	+136	Free running. Good where accuracy is not essential and clearance can be generous.
H8/e8	clearance	+32	+86	Running fit with room for a lubricant film at speed.
H8/f7	clearance	+16	+61	Close running. The general-purpose lubricated journal fit.
H7/g6	clearance	+6	+35	Sliding. Locates accurately, still moves and turns freely.
H7/k6	transition	-12	+17	Locational transition. Accurate location, assembles with light force.
H7/m6	transition	-18	+11	Locational transition, tighter than k6.
H7/n6	transition	-23	+6	Tight transition. Usually a press job.
H7/p6	interference	-29	0	Locational interference. Rigid location in steel without the load capacity of a drive fit.
H7/r6	interference	-34	-5	Medium drive. The joint itself carries load.
F8/h7	clearance	+16	+61	Close running, shaft basis.
G7/h6	clearance	+6	+35	Sliding, shaft basis. The h6 shaft is the reference and the hole carries the clearance.
K7/h6	transition	-12	+17	Locational transition, shaft basis.
N7/h6	transition	-23	+6	Tight transition, shaft basis.
P7/h6	interference	-29	0	Locational interference, shaft basis.

Minimum clearance is the largest shaft in the smallest hole; maximum clearance is the smallest shaft in the largest hole.

Sources and Method for the 12 mm f7 Tolerance

12 mm f7 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.

IT tolerance gradescompiled

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.

Formula

Limits from the deviations at 12 mm

max Ø  =  12 mm + (-16 µm)  =  11.984 mm
min Ø  =  12 mm + (-34 µm)  =  11.966 mm

The deviations are compiled from the ISO 286-2 tables; the limits are those deviations applied to the nominal size.

Assumptions

Values apply at the ISO 286 reference temperature of 20 °C.
Size only. Form, roundness, cylindricity and surface finish are separate callouts and a part inside these limits can still be unusable without them.
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 12 mm f7 Tolerance Reference

Citation

ShopMath. "12 mm f7 Tolerance — Shaft Limits in mm and µm." ShopMath, verified August 1, 2026, https://shopmath.org/fits/f7/12mm

BibTeX

@misc{shopmath-fits-f7-12mm,
  title        = {12 mm f7 Tolerance — Shaft Limits in mm and µm},
  author       = {{ShopMath}},
  year         = {2026},
  howpublished = {\url{https://shopmath.org/fits/f7/12mm}},
  note         = {Data verified 2026-08-01}
}

Permanent URL

https://shopmath.org/fits/f7/12mm

Common Questions About the 12 mm f7 Tolerance

What is the tolerance for a 12 mm f7 shaft?: A 12 mm f7 shaft runs 11.966 to 11.984 mm — deviations of -34 to -16 µm, a band 18 µm wide.
What is the maximum and minimum size of a 12 mm f7 shaft?: Maximum 11.984 mm, minimum 11.966 mm. Anything outside that band is a reject at 20 °C, not a judgement call.
Why is the IT7 band 18 µm at 12 mm?: Because 12 mm falls in the ISO 286 size band over 10 up to 18 mm, and IT7 is defined per band rather than per size. Every nominal size in that band carries the same 18 µm width for IT7.
What shaft goes in a 12 mm f7 hole?: At 12 mm the standard pairs run from H7/h6 (0 to +29 µm clearance) through transition to interference fits — the full list with clearances is on this page.
What does the f in f7 mean?: Close running clearance. It fixes the fundamental deviation — the limit nearest the nominal size — while IT7 fixes the width of the band, which at 12 mm is 18 µm.

All 13 f7 sizes · ISO 286 tolerance chart · Every designation and fit