G6 tolerance (hole, IT6)
Hole tolerance class G6 per ISO 286-1:2010: fundamental deviation EI +2 … +20, grade IT6 (6 µm at ≤ 3 mm to 40 µm at 400–500 mm). For an exact size, open the calculator with G6 selected.
- Type
- Hole
- Grade
- IT6
- Tolerance
- 6 … 40 µm
- Fund. deviation
- EI +2 … +20 µm
G6 limits by size range
| Size (mm) | Upper (µm) | Lower (µm) | Ø max (mm) | Ø min (mm) | Upper (mm) | Lower (mm) | Dev. (in) |
|---|---|---|---|---|---|---|---|
| ≤ 3 | +8 | +2 | 3.008 | 3.002 | +0.008 | +0.002 | +0.00031 / +0.00008 |
| 3 – 6 | +12 | +4 | 6.012 | 6.004 | +0.012 | +0.004 | +0.00047 / +0.00016 |
| 6 – 10 | +14 | +5 | 10.014 | 10.005 | +0.014 | +0.005 | +0.00055 / +0.00020 |
| 10 – 14 | +17 | +6 | 14.017 | 14.006 | +0.017 | +0.006 | +0.00067 / +0.00024 |
| 14 – 18 | +17 | +6 | 18.017 | 18.006 | +0.017 | +0.006 | +0.00067 / +0.00024 |
| 18 – 24 | +20 | +7 | 24.020 | 24.007 | +0.020 | +0.007 | +0.00079 / +0.00028 |
| 24 – 30 | +20 | +7 | 30.020 | 30.007 | +0.020 | +0.007 | +0.00079 / +0.00028 |
| 30 – 40 | +25 | +9 | 40.025 | 40.009 | +0.025 | +0.009 | +0.00098 / +0.00035 |
| 40 – 50 | +25 | +9 | 50.025 | 50.009 | +0.025 | +0.009 | +0.00098 / +0.00035 |
| 50 – 65 | +29 | +10 | 65.029 | 65.010 | +0.029 | +0.010 | +0.00114 / +0.00039 |
| 65 – 80 | +29 | +10 | 80.029 | 80.010 | +0.029 | +0.010 | +0.00114 / +0.00039 |
| 80 – 100 | +34 | +12 | 100.034 | 100.012 | +0.034 | +0.012 | +0.00134 / +0.00047 |
| 100 – 120 | +34 | +12 | 120.034 | 120.012 | +0.034 | +0.012 | +0.00134 / +0.00047 |
| 120 – 140 | +39 | +14 | 140.039 | 140.014 | +0.039 | +0.014 | +0.00154 / +0.00055 |
| 140 – 160 | +39 | +14 | 160.039 | 160.014 | +0.039 | +0.014 | +0.00154 / +0.00055 |
| 160 – 180 | +39 | +14 | 180.039 | 180.014 | +0.039 | +0.014 | +0.00154 / +0.00055 |
| 180 – 200 | +44 | +15 | 200.044 | 200.015 | +0.044 | +0.015 | +0.00173 / +0.00059 |
| 200 – 225 | +44 | +15 | 225.044 | 225.015 | +0.044 | +0.015 | +0.00173 / +0.00059 |
| 225 – 250 | +44 | +15 | 250.044 | 250.015 | +0.044 | +0.015 | +0.00173 / +0.00059 |
| 250 – 280 | +49 | +17 | 280.049 | 280.017 | +0.049 | +0.017 | +0.00193 / +0.00067 |
| 280 – 315 | +49 | +17 | 315.049 | 315.017 | +0.049 | +0.017 | +0.00193 / +0.00067 |
| 315 – 355 | +54 | +18 | 355.054 | 355.018 | +0.054 | +0.018 | +0.00213 / +0.00071 |
| 355 – 400 | +54 | +18 | 400.054 | 400.018 | +0.054 | +0.018 | +0.00213 / +0.00071 |
| 400 – 450 | +60 | +20 | 450.060 | 450.020 | +0.060 | +0.020 | +0.00236 / +0.00079 |
| 450 – 500 | +60 | +20 | 500.060 | 500.020 | +0.060 | +0.020 | +0.00236 / +0.00079 |
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 G6
G6 denotes a hole tolerance zone with sliding deviation in the ISO 286 system. It is used in G6/h5 (Shaft-basis equivalent of H6/g5, built around a ground reference shaft rather than a reamed hole: gauge blocks, instrument slides, precision jig components.).
At Ø25 mm G6 is +0.020 / +0.007 mm, i.e. 25.007 to 25.020 mm.
How the limits are calculated
G6 uses grade IT6 (a standard tolerance of 13 µm at 18–30 mm). Fundamental deviation: EI = −es of the same shaft letter; IT6 sets the width above EI. See the fundamental deviation table for every letter. Values per ISO 286-1:2010.