--- type: "fit" designation: "H7/k6" hole: "H7" shaft: "k6" basis: "hole" classification: "transition" role: "Locational transition. Accurate location, assembles with light force." size_count: 13 standard: "ISO 286-1:2010, ISO 286-2:2010" verified: "August 1, 2026" url: https://shopmath.org/fits/h7-k6 --- # H7/k6 Fit — ISO 286 Transition Fit Limits by Nominal Size H7/k6 is a transition fit: at 25 mm nominal it gives 15 µm interference to 19 µm clearance. Locational transition. Accurate location, assembles with light force. Depending on where each part lands in tolerance, the joint may end up with a small clearance or a small interference. - **Designation**: H7/k6 - **Hole tolerance**: H7 - **Shaft tolerance**: k6 - **Basis**: hole basis - **Classification**: Transition fit - **Typical use**: Locational transition. Accurate location, assembles with light force. - **Standard**: ISO 286-1:2010, ISO 286-2:2010 ## H7/k6 Hole and Shaft Limits by Nominal Size Limits in millimetres, clearances in micrometres. A negative clearance is interference — the shaft is larger than the hole and assembly needs force, heat or cold. | Nominal size | Hole min (mm) | Hole max (mm) | Shaft min (mm) | Shaft max (mm) | Min clearance (µm) | Max clearance (µm) | Result | | --- | --- | --- | --- | --- | --- | --- | --- | | 5 mm | 5.000 | 5.012 | 5.001 | 5.009 | -9 | 11 | Transition | | 6 mm | 6.000 | 6.012 | 6.001 | 6.009 | -9 | 11 | Transition | | 8 mm | 8.000 | 8.015 | 8.001 | 8.010 | -10 | 14 | Transition | | 10 mm | 10.000 | 10.015 | 10.001 | 10.010 | -10 | 14 | Transition | | 12 mm | 12.000 | 12.018 | 12.001 | 12.012 | -12 | 17 | Transition | | 16 mm | 16.000 | 16.018 | 16.001 | 16.012 | -12 | 17 | Transition | | 20 mm | 20.000 | 20.021 | 20.002 | 20.015 | -15 | 19 | Transition | | 25 mm | 25.000 | 25.021 | 25.002 | 25.015 | -15 | 19 | Transition | | 30 mm | 30.000 | 30.021 | 30.002 | 30.015 | -15 | 19 | Transition | | 40 mm | 40.000 | 40.025 | 40.002 | 40.018 | -18 | 23 | Transition | | 50 mm | 50.000 | 50.025 | 50.002 | 50.018 | -18 | 23 | Transition | | 80 mm | 80.000 | 80.030 | 80.002 | 80.021 | -21 | 28 | Transition | | 100 mm | 100.000 | 100.035 | 100.003 | 100.025 | -25 | 32 | Transition | ## Fits Related to H7/k6 Fits that share the H7 hole or the k6 shaft — the alternatives to reach for when H7/k6 is too tight or too loose. | Fit | Classification | Basis | Typical use | | --- | --- | --- | --- | | [H7/g6](https://shopmath.org/fits/h7-g6.md) | Clearance | hole basis | Sliding. Locates accurately, still moves and turns freely. | | [H7/h6](https://shopmath.org/fits/h7-h6.md) | Clearance | both basis | Locational clearance. Assembles by hand, no free movement intended. | | [H7/p6](https://shopmath.org/fits/h7-p6.md) | Interference | hole basis | Locational interference. Rigid location in steel without the load capacity of a drive fit. | | [H7/r6](https://shopmath.org/fits/h7-r6.md) | Interference | hole basis | Medium drive. The joint itself carries load. | | [H7/m6](https://shopmath.org/fits/h7-m6.md) | Transition | hole basis | Locational transition, tighter than k6. | | [H7/n6](https://shopmath.org/fits/h7-n6.md) | Transition | hole basis | Tight transition. Usually a press job. | ## Sources and Method for the H7/k6 Fit ### H7/k6 limits - **Source**: 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 - **Method**: computed - **Verified against**: parkergreene/isofits ISO 286-2 limit tables (MIT); ISO 286-1 formula harness — 2067 checks passed ### 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. Clearance is the assembled gap before any thermal or load effect. - 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 ## Common Questions About the H7/k6 Fit ### What kind of fit is H7/k6? H7/k6 is a transition fit on a hole basis. Depending on where each part lands in tolerance, the joint may end up with a small clearance or a small interference. Locational transition. Accurate location, assembles with light force. ### What is the clearance on a 25 mm H7/k6 fit? At 25 mm nominal, H7/k6 gives 15 µm interference to 19 µm clearance. The hole runs 25.000 to 25.021 mm and the shaft 25.002 to 25.015 mm. ### What hole and shaft tolerances make up H7/k6? H7/k6 pairs a H7 hole with a k6 shaft. On a hole basis, the hole carries the zero-deviation member and the other side is moved to set the fit. ## Related pages - Hole tolerance: [H7 limits by size](https://shopmath.org/fits/h7.md) - Shaft tolerance: [k6 limits by size](https://shopmath.org/fits/k6.md) - All fits and tolerances: [ISO 286 fit reference](https://shopmath.org/fits.md) - Full grade table: [ISO 286 tolerance chart](https://shopmath.org/charts/iso-tolerances.md) --- *Source: [ShopMath](https://shopmath.org/fits/h7-k6) — data verified August 1, 2026. Reference data; verify against the governing standard before manufacture.*