Tolerances for Holes and Shafts
Every shaft and hole in engineering has a tolerance range (the allowable variation for any given size in order to achieve a proper function). Below are the ISO tolerance grades (mm) to calculate accurate hole and shaft measurements for designs.
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Tolerances for Holes (mm)
| Above | Up to and including | H6 | H7 | H8 |
|
0
|
3
|
+0.006 | +0.010 | +0.014 |
| 0 | 0 | 0 | ||
|
3
|
6
|
+0.008 | +0.012 | +0.018 |
| 0 | 0 | 0 | ||
|
6
|
10
|
+0.009 | +0.015 | +0.022 |
| 0 | 0 | 0 | ||
|
10
|
18
|
+0.011 | +0.018 | +0.027 |
| 0 | 0 | 0 | ||
|
18
|
30
|
+0.013 | +0.021 | +0.033 |
| 0 | 0 | 0 | ||
|
30
|
50
|
+0.016 | +0.025 | +0.039 |
| 0 | 0 | 0 | ||
|
50
|
80
|
+0.019 | +0.030 | +0.046 |
| 0 | 0 | 0 | ||
|
80
|
120
|
+0.022 | +0.035 | +0.054 |
| 0 | 0 | 0 | ||
|
120
|
180
|
+0.025 | +0.040 | +0.063 |
| 0 | 0 | 0 | ||
|
180
|
250
|
+0.029 | +0.046 | +0.072 |
| 0 | 0 | 0 | ||
|
250
|
315
|
+0.032 | +0.052 | +0.081 |
| 0 | 0 | 0 | ||
|
315
|
400
|
+0.036 | +0.057 | +0.089 |
| 0 | 0 | 0 | ||
|
400
|
500
|
+0.040 | +0.063 | +0.097 |
| 0 | 0 | 0 |
Tolerances for Shafts (mm)
| Above | Up to and including | h6 | h7 (Slide Fit) | h8 | m6 (Light Drive) | n6 (Semi-med Drive) | p6 (Medium Drive) | g6 (Close Running) |
|
-
|
3
|
0 | 0 | 0 | +0.008 | +0.010 | +0.012 | -0.002 |
| -0.006 | -0.010 | -0.014 | +0.002 | +0.004 | +0.060 | -0.008 | ||
|
3
|
6
|
0 | 0 | 0 | +0.012 | +0.016 | +0.020 | -0.004 |
| -0.008 | -0.012 | -0.018 | +0.004 | +0.008 | +0.012 | -0.012 | ||
|
6
|
10
|
0 | 0 | 0 | +0.015 | +0.019 | +0.024 | -0.005 |
| -0.009 | -0.015 | -0.022 | +0.006 | +0.010 | +0.015 | -0.014 | ||
|
10
|
18
|
0 | 0 | 0 | +0.018 | +0.023 | +0.029 | -0.006 |
| -0.011 | -0.018 | -0.027 | +0.007 | +0.012 | +0.018 | -0.017 | ||
|
18
|
30
|
0 | 0 | 0 | +0.021 | +0.028 | +0.035 | -0.007 |
| -0.013 | -0.021 | -0.033 | +0.008 | +0.015 | +0.022 | -0.020 | ||
|
30
|
50
|
0 | 0 | 0 | +0.025 | +0.033 | +0.042 | -0.009 |
| -0.016 | -0.025 | -0.039 | +0.009 | +0.017 | +0.026 | -0.025 | ||
|
50
|
80
|
0 | 0 | 0 | +0.030 | +0.039 | +0.051 | -0.010 |
| -0.019 | -0.030 | -0.046 | +0.011 | +0.020 | +0.032 | -0.029 | ||
|
80
|
120
|
0 | 0 | 0 | +0.035 | +0.045 | +0.059 | -0.012 |
| -0.022 | -0.035 | -0.054 | +0.013 | +0.023 | +0.037 | -0.034 | ||
|
120
|
180
|
0 | 0 | 0 | +0.040 | +0.052 | +0.068 | -0.014 |
| -0.025 | -0.040 | -0.063 | +0.015 | +0.027 | +0.043 | -0.039 | ||
|
180
|
250
|
0 | 0 | 0 | +0.046 | +0.060 | +0.079 | -0.015 |
| -0.029 | -0.046 | -0.072 | +0.017 | +0.031 | +0.050 | -0.044 | ||
|
250
|
315
|
0 | 0 | 0 | +0.052 | +0.066 | +0.088 | -0.017 |
| -0.032 | -0.052 | -0.081 | +0.020 | +0.034 | +0.056 | -0.049 | ||
|
315
|
400
|
0 | 0 | 0 | +0.057 | +0.073 | +0.096 | -0.018 |
| -0.036 | -0.057 | -0.089 | +0.021 | +0.037 | +0.062 | -0.054 | ||
|
400
|
500
|
0 | 0 | 0 | +0.063 | +0.080 | +0.108 | -0.020 |
| -0.040 | -0.063 | -0.097 | +0.023 | +0.040 | +0.068 | -0.060 |