ISO 286 · g6 shaft · Ø8 mm
8 mm g6 Tolerance — Shaft Limits in mm and µm
https://shopmath.org/fits/g6/8mm · data verified August 1, 2026
A 8 mm g6 shaft is 7.986 to 7.995 mm — deviations of -14 to -5 µm on an IT6 band 9 µm wide. Sliding shaft with minimal clearance — locates accurately and still moves freely. Values apply at the ISO 286 reference temperature of 20 °C.
- Nominal
- 8 mm
- Designation
- g6
- Feature
- shaft
- Grade
- IT6
- Band
- 9 µm
8 mm g6 shaft · limits, mm
7.986 … 7.995
- Upper dev
- -5µm
- Lower dev
- -14µm
- Band
- 9µm
Measured at 20 °C on a plain cylindrical feature. The IT6 grade sets the 9 µm width; the g sets where the band sits.
Limits for a 8 mm g6 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.
| Limit | µm | mm |
|---|---|---|
| Upper deviation | -5 | -0.005 |
| Lower deviation | -14 | -0.014 |
| Maximum diameter | -5 | 7.995 |
| Minimum diameter | -14 | 7.986 |
| Tolerance band (IT6) | 9 | 0.009 |
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.
| 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 g6 or something looser.
| 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.
| 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 g6 Tolerance
- 8 mm g6 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 + (-5 µm) = 7.995 mm min Ø = 8 mm + (-14 µm) = 7.986 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 to Cite This 8 mm g6 Tolerance Reference
Citation
ShopMath. "8 mm g6 Tolerance — Shaft Limits in mm and µm." ShopMath, verified August 1, 2026, https://shopmath.org/fits/g6/8mm
BibTeX
@misc{shopmath-fits-g6-8mm,
title = {8 mm g6 Tolerance — Shaft Limits in mm and µm},
author = {{ShopMath}},
year = {2026},
howpublished = {\url{https://shopmath.org/fits/g6/8mm}},
note = {Data verified 2026-08-01}
}Permanent URL
https://shopmath.org/fits/g6/8mm
Common Questions About the 8 mm g6 Tolerance
What is the tolerance for a 8 mm g6 shaft?
- A 8 mm g6 shaft runs 7.986 to 7.995 mm — deviations of -14 to -5 µm, a band 9 µm wide.
What is the maximum and minimum size of a 8 mm g6 shaft?
- Maximum 7.995 mm, minimum 7.986 mm. Anything outside that band is a reject at 20 °C, not a judgement call.
Why is the IT6 band 9 µm at 8 mm?
- Because 8 mm falls in the ISO 286 size band over 6 up to 10 mm, and IT6 is defined per band rather than per size. Every nominal size in that band carries the same 9 µm width for IT6.
What shaft goes in a 8 mm g6 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 g in g6 mean?
- Sliding, small clearance. It fixes the fundamental deviation — the limit nearest the nominal size — while IT6 fixes the width of the band, which at 8 mm is 9 µm.
All 13 g6 sizes · ISO 286 tolerance chart · Every designation and fit