What is the tolerance for a 8 mm h7 shaft?

A 8 mm h7 shaft runs 7.985 to 8.000 mm — deviations of -15 to 0 µm, a band 15 µm wide.

What is the maximum and minimum size of a 8 mm h7 shaft?

Maximum 8.000 mm, minimum 7.985 mm. Anything outside that band is a reject at 20 °C, not a judgement call.

Why is the IT7 band 15 µm at 8 mm?

Because 8 mm falls in the ISO 286 size band over 6 up to 10 mm, and IT7 is defined per band rather than per size. Every nominal size in that band carries the same 15 µm width for IT7.

What shaft goes in a 8 mm h7 hole?

At 8 mm the standard pairs run from H7/h6 (0 to +24 µm clearance) through transition to interference fits — the full list with clearances is on this page.

What does the h in h7 mean?

Zero deviation — the basic shaft. It fixes the fundamental deviation — the limit nearest the nominal size — while IT7 fixes the width of the band, which at 8 mm is 15 µm.

ISO 286 · h7 shaft · Ø8 mm

8 mm h7 Tolerance — Shaft Limits in mm and µm

https://shopmath.org/fits/h7-shaft/8mm · data verified August 1, 2026

A 8 mm h7 shaft is 7.985 to 8.000 mm — deviations of -15 to 0 µm on an IT7 band 15 µm wide. Basic shaft one grade coarser than h6, for shaft-basis close running fits. Values apply at the ISO 286 reference temperature of 20 °C.

Nominal: 8 mm
Designation: h7
Feature: shaft
Grade: IT7
Band: 15 µm

8 mm h7 shaft · limits, mm

7.985 … 8.000

Upper dev: 0µm
Lower dev: -15µm
Band: 15µm

Measured at 20 °C on a plain cylindrical feature. The IT7 grade sets the 15 µm width; the h sets where the band sits.

Limits for a 8 mm h7 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.

8 mm h7 shaft tolerance — deviations and limits
Limit	µm	mm
Upper deviation	0	0.000
Lower deviation	-15	-0.015
Maximum diameter	0	8.000
Minimum diameter	-15	7.985
Tolerance band (IT7)	15	0.015

Deviations are relative to the 8 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 8 mm

8 mm falls in the ISO 286 size band over 6 to 10 mm, so every tolerance in that band has the same width regardless of which letter it carries.

ISO 286 standard tolerance grades at 8 mm nominal size
Grade	Tolerance, µm	Tolerance, mm
IT5	6	0.006
IT6	9	0.009
IT7	15	0.015
IT8	22	0.022
IT9	36	0.036
IT10	58	0.058
IT11	90	0.090
IT12	150	0.150

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 8 mm

The same nominal size under every other designation in this reference — the comparison that decides whether a feature is called out h7 or something looser.

ISO 286 hole and shaft tolerances at 8 mm nominal size
Property	Property	Deviation, µm		Limits, mm
Designation	Applies to	Upper	Lower	Min	Max
c11	shaft	-80	-170	7.830	7.920
d9	shaft	-40	-76	7.924	7.960
e8	shaft	-25	-47	7.953	7.975
f7	shaft	-13	-28	7.972	7.987
g6	shaft	-5	-14	7.986	7.995
h11	shaft	0	-90	7.910	8.000
h6	shaft	0	-9	7.991	8.000
h7	shaft	0	-15	7.985	8.000
h9	shaft	0	-36	7.964	8.000
k6	shaft	+10	+1	8.001	8.010
m6	shaft	+15	+6	8.006	8.015
n6	shaft	+19	+10	8.010	8.019
p6	shaft	+24	+15	8.015	8.024
r6	shaft	+28	+19	8.019	8.028
F8	hole	+35	+13	8.013	8.035
G7	hole	+20	+5	8.005	8.020
H11	hole	+90	0	8.000	8.090
H6	hole	+9	0	8.000	8.009
H7	hole	+15	0	8.000	8.015
H8	hole	+22	0	8.000	8.022
H9	hole	+36	0	8.000	8.036
K7	hole	+5	-10	7.990	8.005
N7	hole	-4	-19	7.981	7.996
P7	hole	-9	-24	7.976	7.991

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

Standard Fits Available at 8 mm

What each standard hole/shaft pair gives at 8 mm, loosest first. Negative clearance is interference.

ISO 286 fits and their clearance at 8 mm nominal size
Property	Property	Clearance, µm		Property
Fit	Type	Min	Max	What it is for
H7/h6	clearance	0	+24	Locational clearance. Assembles by hand, no free movement intended.
H11/c11	clearance	+80	+260	Loose running. Wide commercial tolerances, large clearance for dirt, paint and thermal growth.
H9/d9	clearance	+40	+112	Free running. Good where accuracy is not essential and clearance can be generous.
H8/e8	clearance	+25	+69	Running fit with room for a lubricant film at speed.
H8/f7	clearance	+13	+50	Close running. The general-purpose lubricated journal fit.
H7/g6	clearance	+5	+29	Sliding. Locates accurately, still moves and turns freely.
H7/k6	transition	-10	+14	Locational transition. Accurate location, assembles with light force.
H7/m6	transition	-15	+9	Locational transition, tighter than k6.
H7/n6	transition	-19	+5	Tight transition. Usually a press job.
H7/p6	interference	-24	0	Locational interference. Rigid location in steel without the load capacity of a drive fit.
H7/r6	interference	-28	-4	Medium drive. The joint itself carries load.
F8/h7	clearance	+13	+50	Close running, shaft basis.
G7/h6	clearance	+5	+29	Sliding, shaft basis. The h6 shaft is the reference and the hole carries the clearance.
K7/h6	transition	-10	+14	Locational transition, shaft basis.
N7/h6	transition	-19	+5	Tight transition, shaft basis.
P7/h6	interference	-24	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 8 mm h7 Tolerance

8 mm h7 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 8 mm

max Ø  =  8 mm + (0 µm)  =  8.000 mm
min Ø  =  8 mm + (-15 µm)  =  7.985 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 8 mm h7 Tolerance Reference

Citation

ShopMath. "8 mm h7 Tolerance — Shaft Limits in mm and µm." ShopMath, verified August 1, 2026, https://shopmath.org/fits/h7-shaft/8mm

BibTeX

@misc{shopmath-fits-h7-shaft-8mm,
  title        = {8 mm h7 Tolerance — Shaft Limits in mm and µm},
  author       = {{ShopMath}},
  year         = {2026},
  howpublished = {\url{https://shopmath.org/fits/h7-shaft/8mm}},
  note         = {Data verified 2026-08-01}
}

Permanent URL

https://shopmath.org/fits/h7-shaft/8mm

Common Questions About the 8 mm h7 Tolerance

What is the tolerance for a 8 mm h7 shaft?: A 8 mm h7 shaft runs 7.985 to 8.000 mm — deviations of -15 to 0 µm, a band 15 µm wide.
What is the maximum and minimum size of a 8 mm h7 shaft?: Maximum 8.000 mm, minimum 7.985 mm. Anything outside that band is a reject at 20 °C, not a judgement call.
Why is the IT7 band 15 µm at 8 mm?: Because 8 mm falls in the ISO 286 size band over 6 up to 10 mm, and IT7 is defined per band rather than per size. Every nominal size in that band carries the same 15 µm width for IT7.
What shaft goes in a 8 mm h7 hole?: At 8 mm the standard pairs run from H7/h6 (0 to +24 µm clearance) through transition to interference fits — the full list with clearances is on this page.
What does the h in h7 mean?: Zero deviation — the basic shaft. It fixes the fundamental deviation — the limit nearest the nominal size — while IT7 fixes the width of the band, which at 8 mm is 15 µm.

All 13 h7 sizes · ISO 286 tolerance chart · Every designation and fit