m7 tolerance (shaft, IT7)
Shaft tolerance class m7 per ISO 286-1:2010: fundamental deviation ei +2 … +23, grade IT7 (10 µm at ≤ 3 mm to 63 µm at 400–500 mm). For an exact size, open the calculator with m7 selected.
- Type
- Shaft
- Grade
- IT7
- Tolerance
- 10 … 63 µm
- Fund. deviation
- ei +2 … +23 µm
m7 limits by size range
| Size (mm) | Upper (µm) | Lower (µm) | Ø max (mm) | Ø min (mm) | Upper (mm) | Lower (mm) | Dev. (in) |
|---|---|---|---|---|---|---|---|
| ≤ 3 | +12 | +2 | 3.012 | 3.002 | +0.012 | +0.002 | +0.00047 / +0.00008 |
| 3 – 6 | +16 | +4 | 6.016 | 6.004 | +0.016 | +0.004 | +0.00063 / +0.00016 |
| 6 – 10 | +21 | +6 | 10.021 | 10.006 | +0.021 | +0.006 | +0.00083 / +0.00024 |
| 10 – 14 | +25 | +7 | 14.025 | 14.007 | +0.025 | +0.007 | +0.00098 / +0.00028 |
| 14 – 18 | +25 | +7 | 18.025 | 18.007 | +0.025 | +0.007 | +0.00098 / +0.00028 |
| 18 – 24 | +29 | +8 | 24.029 | 24.008 | +0.029 | +0.008 | +0.00114 / +0.00031 |
| 24 – 30 | +29 | +8 | 30.029 | 30.008 | +0.029 | +0.008 | +0.00114 / +0.00031 |
| 30 – 40 | +34 | +9 | 40.034 | 40.009 | +0.034 | +0.009 | +0.00134 / +0.00035 |
| 40 – 50 | +34 | +9 | 50.034 | 50.009 | +0.034 | +0.009 | +0.00134 / +0.00035 |
| 50 – 65 | +41 | +11 | 65.041 | 65.011 | +0.041 | +0.011 | +0.00161 / +0.00043 |
| 65 – 80 | +41 | +11 | 80.041 | 80.011 | +0.041 | +0.011 | +0.00161 / +0.00043 |
| 80 – 100 | +48 | +13 | 100.048 | 100.013 | +0.048 | +0.013 | +0.00189 / +0.00051 |
| 100 – 120 | +48 | +13 | 120.048 | 120.013 | +0.048 | +0.013 | +0.00189 / +0.00051 |
| 120 – 140 | +55 | +15 | 140.055 | 140.015 | +0.055 | +0.015 | +0.00217 / +0.00059 |
| 140 – 160 | +55 | +15 | 160.055 | 160.015 | +0.055 | +0.015 | +0.00217 / +0.00059 |
| 160 – 180 | +55 | +15 | 180.055 | 180.015 | +0.055 | +0.015 | +0.00217 / +0.00059 |
| 180 – 200 | +63 | +17 | 200.063 | 200.017 | +0.063 | +0.017 | +0.00248 / +0.00067 |
| 200 – 225 | +63 | +17 | 225.063 | 225.017 | +0.063 | +0.017 | +0.00248 / +0.00067 |
| 225 – 250 | +63 | +17 | 250.063 | 250.017 | +0.063 | +0.017 | +0.00248 / +0.00067 |
| 250 – 280 | +72 | +20 | 280.072 | 280.020 | +0.072 | +0.020 | +0.00283 / +0.00079 |
| 280 – 315 | +72 | +20 | 315.072 | 315.020 | +0.072 | +0.020 | +0.00283 / +0.00079 |
| 315 – 355 | +78 | +21 | 355.078 | 355.021 | +0.078 | +0.021 | +0.00307 / +0.00083 |
| 355 – 400 | +78 | +21 | 400.078 | 400.021 | +0.078 | +0.021 | +0.00307 / +0.00083 |
| 400 – 450 | +86 | +23 | 450.086 | 450.023 | +0.086 | +0.023 | +0.00339 / +0.00091 |
| 450 – 500 | +86 | +23 | 500.086 | 500.023 | +0.086 | +0.023 | +0.00339 / +0.00091 |
Deviations at the upper end of each range (Ø columns use that size); use the calculator for the exact size. — : not defined by ISO 286 for that size. Upper/Lower (mm) and inch columns are shown on wider screens.
About m7
m7 denotes a shaft tolerance zone with tight transition deviation in the ISO 286 system. It is used in H8/m7 (Tighter than H8/n7, on an IT8 hole; a press-assembled locational fit for parts that must resist vibration but stay removable, where full H7/m6 precision isn't justified.).
At Ø25 mm m7 is +0.029 / +0.008 mm, i.e. 25.008 to 25.029 mm.
How the limits are calculated
m7 uses grade IT7 (a standard tolerance of 21 µm at 18–30 mm). Fundamental deviation: ei is tabulated directly by ISO 286-1 Table 2; es = ei + IT7. See the fundamental deviation table for every letter. Values per ISO 286-1:2010.