---
type: "hub"
name: "ISO 286 fit and tolerance reference"
designation_count: 24
fit_count: 16
nominal_sizes_mm: ["5", "6", "8", "10", "12", "16", "20", "25", "30", "40", "50", "80", "100"]
standard: "ISO 286-1:2010, ISO 286-2:2010"
verified: "August 1, 2026"
url: https://shopmath.org/fits
---

# ISO 286 Fits and Tolerances — Hole and Shaft Limits Reference

24 ISO 286 tolerance designations and 16 standard hole/shaft fits, each with limits and deviations tabulated across 13 nominal sizes from 5 to 100 mm. A designation such as H7 sets where a tolerance band sits and how wide it is; a fit such as H7/g6 pairs a hole with a shaft and states the resulting clearance.

## Fit Classifications

| Classification | Fits | What it means |
| --- | --- | --- |
| Clearance fit | 8 | The hole is always larger than the shaft — the parts always assemble with a gap. |
| Interference fit | 3 | The shaft is always larger than the hole — assembly needs force, heat or cold. |
| Transition fit | 5 | Depending on where each part lands in tolerance, the joint may end up with a small clearance or a small interference. |

_A classification appears here only when at least three standard fits fall into it._

## Standard Hole and Shaft Fits

Each fit links to its limits and clearance across every nominal size.

| Fit | Hole | Shaft | Basis | Classification | Typical use |
| --- | --- | --- | --- | --- | --- |
| [H7/h6](https://shopmath.org/fits/h7-h6.md) | H7 | h6 | both basis | Clearance | Locational clearance. Assembles by hand, no free movement intended. |
| [H11/c11](https://shopmath.org/fits/h11-c11.md) | H11 | c11 | hole basis | 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 | hole basis | Clearance | Sliding. Locates accurately, still moves and turns freely. |
| [H8/e8](https://shopmath.org/fits/h8-e8.md) | H8 | e8 | hole basis | Clearance | Running fit with room for a lubricant film at speed. |
| [H8/f7](https://shopmath.org/fits/h8-f7.md) | H8 | f7 | hole basis | Clearance | Close running. The general-purpose lubricated journal fit. |
| [H9/d9](https://shopmath.org/fits/h9-d9.md) | H9 | d9 | hole basis | 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 | hole basis | 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 | hole basis | Interference | Medium drive. The joint itself carries load. |
| [H7/k6](https://shopmath.org/fits/h7-k6.md) | H7 | k6 | hole basis | Transition | Locational transition. Accurate location, assembles with light force. |
| [H7/m6](https://shopmath.org/fits/h7-m6.md) | H7 | m6 | hole basis | Transition | Locational transition, tighter than k6. |
| [H7/n6](https://shopmath.org/fits/h7-n6.md) | H7 | n6 | hole basis | Transition | Tight transition. Usually a press job. |
| [F8/h7](https://shopmath.org/fits/f8-h7.md) | F8 | h7 | shaft basis | Clearance | Close running, shaft basis. |
| [G7/h6](https://shopmath.org/fits/g7-h6.md) | G7 | h6 | shaft basis | 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 | shaft basis | Interference | Locational interference, shaft basis. |
| [K7/h6](https://shopmath.org/fits/k7-h6.md) | K7 | h6 | shaft basis | Transition | Locational transition, shaft basis. |
| [N7/h6](https://shopmath.org/fits/n7-h6.md) | N7 | h6 | shaft basis | Transition | Tight transition, shaft basis. |

## ISO 286 Tolerance Designations

Individual hole and shaft tolerances. Uppercase letters are holes, lowercase are shafts — H7 and h7 are different things and both are listed.

| Designation | Feature | Letter | Grade | Deviation meaning | Typical use |
| --- | --- | --- | --- | --- | --- |
| [c11](https://shopmath.org/fits/c11.md) | shaft | c | ITIT11 | Loose running clearance | Loose running shaft for wide commercial tolerances and hot-running assemblies. |
| [d9](https://shopmath.org/fits/d9.md) | shaft | d | ITIT9 | Free running clearance | Free running shaft where accuracy is not essential. |
| [e8](https://shopmath.org/fits/e8.md) | shaft | e | ITIT8 | Running clearance | Running shaft with generous clearance for lubrication at speed. |
| [f7](https://shopmath.org/fits/f7.md) | shaft | f | ITIT7 | Close running clearance | Close running shaft — the standard choice for lubricated journals at moderate speed. |
| [g6](https://shopmath.org/fits/g6.md) | shaft | g | ITIT6 | Sliding, small clearance | Sliding shaft with minimal clearance — locates accurately and still moves freely. |
| [h11](https://shopmath.org/fits/h11-shaft.md) | shaft | h | ITIT11 | Zero deviation — the basic shaft | Wide-tolerance basic shaft matching drawn or cold-finished bar. |
| [h6](https://shopmath.org/fits/h6.md) | shaft | h | ITIT6 | Zero deviation — the basic shaft | Precision basic shaft — zero upper deviation, the reference for locational clearance fits. |
| [h7](https://shopmath.org/fits/h7-shaft.md) | shaft | h | ITIT7 | Zero deviation — the basic shaft | Basic shaft one grade coarser than h6, for shaft-basis close running fits. |
| [h9](https://shopmath.org/fits/h9-shaft.md) | shaft | h | ITIT9 | Zero deviation — the basic shaft | Basic shaft for shaft-basis free running fits. |
| [k6](https://shopmath.org/fits/k6.md) | shaft | k | ITIT6 | Transition, light drive | Transition shaft — accurate location, assembles and disassembles with light force. |
| [m6](https://shopmath.org/fits/m6.md) | shaft | m | ITIT6 | Transition, tighter | Transition shaft biased tighter than k6. |
| [n6](https://shopmath.org/fits/n6.md) | shaft | n | ITIT6 | Tight transition | Tight transition shaft — usually needs a press for assembly. |
| [p6](https://shopmath.org/fits/p6.md) | shaft | p | ITIT6 | Light interference | Light interference shaft for locational press fits in steel. |
| [r6](https://shopmath.org/fits/r6.md) | shaft | r | ITIT6 | Medium interference | Medium drive shaft for interference fits that transmit load through the joint. |
| [F8](https://shopmath.org/fits/f8.md) | hole | F | ITIT8 | Close running clearance | Close running hole for shaft-basis fits with lubrication. |
| [G7](https://shopmath.org/fits/g7.md) | hole | G | ITIT7 | Sliding, small clearance | Small positive clearance hole for shaft-basis sliding fits. |
| [H11](https://shopmath.org/fits/h11.md) | hole | H | ITIT11 | Zero deviation — the basic hole | Wide-tolerance basic hole for loose running fits and cold-finished stock. |
| [H6](https://shopmath.org/fits/h6-hole.md) | hole | H | ITIT6 | Zero deviation — the basic hole | Precision basic hole for close-running and transition fits. |
| [H7](https://shopmath.org/fits/h7.md) | hole | H | ITIT7 | Zero deviation — the basic hole | The default basic hole in hole-basis fitting — reamer and gauge sizes are built around it. |
| [H8](https://shopmath.org/fits/h8.md) | hole | H | ITIT8 | Zero deviation — the basic hole | Basic hole where a close running fit is wanted but H7 is more precision than the job needs. |
| [H9](https://shopmath.org/fits/h9.md) | hole | H | ITIT9 | Zero deviation — the basic hole | Basic hole for free running fits with generous clearance. |
| [K7](https://shopmath.org/fits/k7.md) | hole | K | ITIT7 | Transition, light drive | Shaft-basis transition hole — locates accurately, still assembles with light force. |
| [N7](https://shopmath.org/fits/n7.md) | hole | N | ITIT7 | Tight transition | Shaft-basis transition hole biased toward interference. |
| [P7](https://shopmath.org/fits/p7.md) | hole | P | ITIT7 | Light interference | Shaft-basis light interference hole. |

## Sources and Method for the ISO 286 Data

### 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

- Full grade table: [ISO 286 tolerance chart](https://shopmath.org/charts/iso-tolerances.md)
- Threads: [Screw thread reference](https://shopmath.org/threads.md)
- Drill sizes: [Drill bit size reference](https://shopmath.org/drills.md)

---

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