---
type: "chart"
name: "ISO 286 tolerance chart"
grade_count: 8
size_band_count: 13
designation_count: 24
fit_count: 16
standard: "ISO 286-1:2010, ISO 286-2:2010"
verified: "August 1, 2026"
url: https://shopmath.org/charts/iso-tolerances
---

# ISO 286 Tolerance Chart — IT Grades, Designations and Standard Fits

The ISO 286 standard tolerance grades across 13 nominal size bands, in micrometres, plus every tolerance designation and standard hole/shaft fit this reference covers. The IT grade sets how wide a tolerance band is; the letter sets where it sits relative to the nominal size. Together they make a designation such as H7.

## IT Grade Tolerances by Nominal Size Band

Values in micrometres. Read down to your size band, across to your grade.

| Nominal size band | IT5 | IT6 | IT7 | IT8 | IT9 | IT10 | IT11 | IT12 |
| --- | --- | --- | --- | --- | --- | --- | --- | --- |
| over 0 to 3 mm | 4 | 6 | 10 | 14 | 25 | 40 | 60 | 100 |
| over 3 to 6 mm | 5 | 8 | 12 | 18 | 30 | 48 | 75 | 120 |
| over 6 to 10 mm | 6 | 9 | 15 | 22 | 36 | 58 | 90 | 150 |
| over 10 to 18 mm | 8 | 11 | 18 | 27 | 43 | 70 | 110 | 180 |
| over 18 to 30 mm | 9 | 13 | 21 | 33 | 52 | 84 | 130 | 210 |
| over 30 to 50 mm | 11 | 16 | 25 | 39 | 62 | 100 | 160 | 250 |
| over 50 to 80 mm | 13 | 19 | 30 | 46 | 74 | 120 | 190 | 300 |
| over 80 to 120 mm | 15 | 22 | 35 | 54 | 87 | 140 | 220 | 350 |
| over 120 to 180 mm | 18 | 25 | 40 | 63 | 100 | 160 | 250 | 400 |
| over 180 to 250 mm | 20 | 29 | 46 | 72 | 115 | 185 | 290 | 460 |
| over 250 to 315 mm | 23 | 32 | 52 | 81 | 130 | 210 | 320 | 520 |
| over 315 to 400 mm | 25 | 36 | 57 | 89 | 140 | 230 | 360 | 570 |
| over 400 to 500 mm | 27 | 40 | 63 | 97 | 155 | 250 | 400 | 630 |

_ISO 286 tabulates per band, so a value holds across the whole band, not just at one diameter. Limits are at 20 °C, the ISO 1 reference temperature._

## Tolerance Designations

Uppercase letters are holes, lowercase are shafts. Each links to its limits at every nominal size.

| Designation | Feature | Letter | Grade | What the deviation does |
| --- | --- | --- | --- | --- |
| [c11](https://shopmath.org/fits/c11.md) | shaft | c | ITIT11 | Loose running clearance |
| [d9](https://shopmath.org/fits/d9.md) | shaft | d | ITIT9 | Free running clearance |
| [e8](https://shopmath.org/fits/e8.md) | shaft | e | ITIT8 | Running clearance |
| [f7](https://shopmath.org/fits/f7.md) | shaft | f | ITIT7 | Close running clearance |
| [g6](https://shopmath.org/fits/g6.md) | shaft | g | ITIT6 | Sliding, small clearance |
| [h11](https://shopmath.org/fits/h11-shaft.md) | shaft | h | ITIT11 | Zero deviation — the basic shaft |
| [h6](https://shopmath.org/fits/h6.md) | shaft | h | ITIT6 | Zero deviation — the basic shaft |
| [h7](https://shopmath.org/fits/h7-shaft.md) | shaft | h | ITIT7 | Zero deviation — the basic shaft |
| [h9](https://shopmath.org/fits/h9-shaft.md) | shaft | h | ITIT9 | Zero deviation — the basic shaft |
| [k6](https://shopmath.org/fits/k6.md) | shaft | k | ITIT6 | Transition, light drive |
| [m6](https://shopmath.org/fits/m6.md) | shaft | m | ITIT6 | Transition, tighter |
| [n6](https://shopmath.org/fits/n6.md) | shaft | n | ITIT6 | Tight transition |
| [p6](https://shopmath.org/fits/p6.md) | shaft | p | ITIT6 | Light interference |
| [r6](https://shopmath.org/fits/r6.md) | shaft | r | ITIT6 | Medium interference |
| [F8](https://shopmath.org/fits/f8.md) | hole | F | ITIT8 | Close running clearance |
| [G7](https://shopmath.org/fits/g7.md) | hole | G | ITIT7 | Sliding, small clearance |
| [H11](https://shopmath.org/fits/h11.md) | hole | H | ITIT11 | Zero deviation — the basic hole |
| [H6](https://shopmath.org/fits/h6-hole.md) | hole | H | ITIT6 | Zero deviation — the basic hole |
| [H7](https://shopmath.org/fits/h7.md) | hole | H | ITIT7 | Zero deviation — the basic hole |
| [H8](https://shopmath.org/fits/h8.md) | hole | H | ITIT8 | Zero deviation — the basic hole |
| [H9](https://shopmath.org/fits/h9.md) | hole | H | ITIT9 | Zero deviation — the basic hole |
| [K7](https://shopmath.org/fits/k7.md) | hole | K | ITIT7 | Transition, light drive |
| [N7](https://shopmath.org/fits/n7.md) | hole | N | ITIT7 | Tight transition |
| [P7](https://shopmath.org/fits/p7.md) | hole | P | ITIT7 | Light interference |

## Standard Hole and Shaft Fits

| Fit | Hole | Shaft | Classification | Typical use |
| --- | --- | --- | --- | --- |
| [H7/h6](https://shopmath.org/fits/h7-h6.md) | H7 | h6 | Clearance | Locational clearance. Assembles by hand, no free movement intended. |
| [H11/c11](https://shopmath.org/fits/h11-c11.md) | H11 | c11 | Clearance | Loose running. Wide commercial tolerances, large clearance for dirt, paint and thermal growth. |
| [H7/g6](https://shopmath.org/fits/h7-g6.md) | H7 | g6 | Clearance | Sliding. Locates accurately, still moves and turns freely. |
| [H8/e8](https://shopmath.org/fits/h8-e8.md) | H8 | e8 | Clearance | Running fit with room for a lubricant film at speed. |
| [H8/f7](https://shopmath.org/fits/h8-f7.md) | H8 | f7 | Clearance | Close running. The general-purpose lubricated journal fit. |
| [H9/d9](https://shopmath.org/fits/h9-d9.md) | H9 | d9 | Clearance | Free running. Good where accuracy is not essential and clearance can be generous. |
| [H7/p6](https://shopmath.org/fits/h7-p6.md) | H7 | p6 | Interference | Locational interference. Rigid location in steel without the load capacity of a drive fit. |
| [H7/r6](https://shopmath.org/fits/h7-r6.md) | H7 | r6 | Interference | Medium drive. The joint itself carries load. |
| [H7/k6](https://shopmath.org/fits/h7-k6.md) | H7 | k6 | Transition | Locational transition. Accurate location, assembles with light force. |
| [H7/m6](https://shopmath.org/fits/h7-m6.md) | H7 | m6 | Transition | Locational transition, tighter than k6. |
| [H7/n6](https://shopmath.org/fits/h7-n6.md) | H7 | n6 | Transition | Tight transition. Usually a press job. |
| [F8/h7](https://shopmath.org/fits/f8-h7.md) | F8 | h7 | Clearance | Close running, shaft basis. |
| [G7/h6](https://shopmath.org/fits/g7-h6.md) | G7 | h6 | Clearance | Sliding, shaft basis. The h6 shaft is the reference and the hole carries the clearance. |
| [P7/h6](https://shopmath.org/fits/p7-h6.md) | P7 | h6 | Interference | Locational interference, shaft basis. |
| [K7/h6](https://shopmath.org/fits/k7-h6.md) | K7 | h6 | Transition | Locational transition, shaft basis. |
| [N7/h6](https://shopmath.org/fits/n7-h6.md) | N7 | h6 | Transition | Tight transition, shaft basis. |

## Sources and Method for the ISO 286 Tolerance Chart

### ISO 286 IT grades, fundamental deviations and fits

- **Source**: saucecode/ISO286 (LGPL-2.1) + parkergreene/isofits (MIT), cross-checked cell-for-cell
- **Method**: compiled
- **Verified against**: fits-iso286: 2067 checks passed across 3 harness(es)

### Assumptions

- Values are the ISO 286-2 tabulated limits, not the ISO 286-1 formula: the formula deviates from the table by up to 13.26% and is carried only as a validation harness.
- Limits are at 20 °C, the ISO 1 reference temperature.
- 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

## Related pages

- Fits and designations: [ISO 286 fit reference](https://shopmath.org/fits.md)
- Sheet metal: [Sheet metal gauge chart](https://shopmath.org/charts/sheet-metal-gauge.md)

---

*Source: [ShopMath](https://shopmath.org/charts/iso-tolerances) — data verified August 1, 2026. Reference data; verify against the governing standard before manufacture.*