--- type: "fit" designation: "H7/m6" hole: "H7" shaft: "m6" basis: "hole" classification: "transition" role: "Locational transition, tighter than k6." size_count: 13 standard: "ISO 286-1:2010, ISO 286-2:2010" verified: "August 1, 2026" url: https://shopmath.org/fits/h7-m6 --- # H7/m6 Fit — ISO 286 Transition Fit Limits by Nominal Size H7/m6 is a transition fit: at 25 mm nominal it gives 21 µm interference to 13 µm clearance. Locational transition, tighter than k6. Depending on where each part lands in tolerance, the joint may end up with a small clearance or a small interference. - **Designation**: H7/m6 - **Hole tolerance**: H7 - **Shaft tolerance**: m6 - **Basis**: hole basis - **Classification**: Transition fit - **Typical use**: Locational transition, tighter than k6. - **Standard**: ISO 286-1:2010, ISO 286-2:2010 ## H7/m6 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 | 5.004 | 5.012 | -12 | 8 | Transition | | 6 mm | 6.000 | 6.012 | 6.004 | 6.012 | -12 | 8 | Transition | | 8 mm | 8.000 | 8.015 | 8.006 | 8.015 | -15 | 9 | Transition | | 10 mm | 10.000 | 10.015 | 10.006 | 10.015 | -15 | 9 | Transition | | 12 mm | 12.000 | 12.018 | 12.007 | 12.018 | -18 | 11 | Transition | | 16 mm | 16.000 | 16.018 | 16.007 | 16.018 | -18 | 11 | Transition | | 20 mm | 20.000 | 20.021 | 20.008 | 20.021 | -21 | 13 | Transition | | 25 mm | 25.000 | 25.021 | 25.008 | 25.021 | -21 | 13 | Transition | | 30 mm | 30.000 | 30.021 | 30.008 | 30.021 | -21 | 13 | Transition | | 40 mm | 40.000 | 40.025 | 40.009 | 40.025 | -25 | 16 | Transition | | 50 mm | 50.000 | 50.025 | 50.009 | 50.025 | -25 | 16 | Transition | | 80 mm | 80.000 | 80.030 | 80.011 | 80.030 | -30 | 19 | Transition | | 100 mm | 100.000 | 100.035 | 100.013 | 100.035 | -35 | 22 | Transition | ## Fits Related to H7/m6 Fits that share the H7 hole or the m6 shaft — the alternatives to reach for when H7/m6 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/k6](https://shopmath.org/fits/h7-k6.md) | Transition | hole basis | Locational transition. Accurate location, assembles with light force. | | [H7/n6](https://shopmath.org/fits/h7-n6.md) | Transition | hole basis | Tight transition. Usually a press job. | ## Sources and Method for the H7/m6 Fit ### H7/m6 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/m6 Fit ### What kind of fit is H7/m6? H7/m6 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, tighter than k6. ### What is the clearance on a 25 mm H7/m6 fit? At 25 mm nominal, H7/m6 gives 21 µm interference to 13 µm clearance. The hole runs 25.000 to 25.021 mm and the shaft 25.008 to 25.021 mm. ### What hole and shaft tolerances make up H7/m6? H7/m6 pairs a H7 hole with a m6 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: [m6 limits by size](https://shopmath.org/fits/m6.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-m6) — data verified August 1, 2026. Reference data; verify against the governing standard before manufacture.*