Tap Tolerances
Tolerance Chart - UNC/UNCF
EMUGE has determined that the tolerance of the tap should be manufactured as close as possible to the finished internal thread tolerance.
This practice ensures that the threads produced will comply to the gage tolerances providing that the working conditions such as machine, chucking tools, and workpiece match the application.
EMUGE taps are marked with the appropriate tolerance class for their intended use. The U.S. GH thread class numbers are not marked on the tap.
Tolerances for the various GH numbers are shown in the chart opposite.
Classification for the tolerance 1B can be provided upon request.
Taps for cast iron and titanium tapping are designed one GH class higher to provide better tool life.
| UNC Thread | Tap Limit | UNF Thread | Tap Limit | ||
|---|---|---|---|---|---|
| 3B (Tap) | 2B (Tap) | 3B (Tap) | 2B (Tap) | ||
| No. 1 - 64 | H1 / H2 | H2 / H3 | No. 0 - 80 | H1 | H1 / H2 |
| No. 2 - 56 | H1 / H2 | H2 / H3 | No. 1 - 72 | H1 / H2 | H2 / H3 |
| No. 3 - 48 | H1 / H2 | H2 / H3 | No. 2 - 64 | H1 / H2 | H2 / H3 |
| No. 4 - 40 | H2 | H2 / H3 | No. 3 - 56 | H1 / H2 | H2 / H3 |
| No. 5 - 40 | H2 | H2 / H3 | No. 4 - 48 | H2 | H2 / H3 |
| No. 6 - 32 | H2 | H3 / H4 | No. 5 - 44 | H2 | H2 / H3 |
| No. 8 - 32 | H2 | H3 / H4 | No. 6 - 40 | H2 | H2 / H3 |
| No. 10 - 24 | H2 / H3 | H3 / H4 | No. 8 - 36 | H2 | H2 / H3 |
| No. 12 - 24 | H2 / H3 | H3 / H4 | No. 10 - 32 | H2 | H2 / H3 |
| 1/4 - 20 | H3 | H4 / H5 | No. 12 - 28 | H2 / H3 | H3 / H4 |
| 5/16 - 18 | H3 | H4 / H5 | 1/4 - 28 | H2 / H3 | H3 / H4 |
| 3/8 - 16 | H3 / H4 | H4 / H5 | 5/16 - 24 | H3 | H3 / H4 |
| 7/16 - 14 | H3 / H4 | H4 / H5 | 3/8 - 24 | H3 | H3 / H4 |
| 1/2 - 13 | H4 | H5 / H6 | 7/16 - 20 | H3 | H4 / H5 |
| 9/16 - 12 | H4 | H5 / H6 | 1/2 - 20 | H3 | H4 / H5 |
| 5/8 - 11 | H4 | H5 / H6 | 9/16 - 18 | H3 / H4 | H4 / H5 |
| 3/4 - 10 | H4 / H5 | H6 / H7 | 5/8 - 18 | H3 / H4 | H5 / H6 |
| 7/8 - 9 | H4 / H5 | H6 / H7 | 3/4 - 16 | H4 | H5 / H6 |
| 1 - 8 | H5 | H6 / H7 | 7/8 - 14 | H4 | H5 / H6 |
| 1 1/8 - 7 | H5 | H7 / H8 | 1 - 12 | H4 / H5 | H5 / H6 |
| 1 1/4 - 7 | H5 / H6 | H7 / H8 | 1 1/8 - 12 | H4 / H5 | H6 / H7 |
| 1 3/8 - 6 | H6 | H7 / H8 | 1 1/4 - 12 | H4 / H5 | H6 / H7 |
| 1 1/2 - 6 | H6 | H7 / H8 | 1 3/8 - 12 | H4 / H5 | H6 / H7 |
| 1 3/4 - 5 | H6 / H7 | H8 / H9 | 1 1/12 - 12 | H4 / H5 | H6 / H7 |
| 2 - 4 1/2 | H7 | H8 / H9 | |||
Tolerance Chart - Metric Coarse / Fine
The approved tap tolerance system for metric ISO threads is International Standard ISO 2857.
· 4H tap corresponds to ISO 1
· 6H tap corresponds to ISO 2
· 6G tap corresponds to ISO 3
4H and 6G taps can be supplied upon request. 6G taps are Oversize. Please refer to the Au "G" values table below.
The U.S. GD tap class numbers are not marked on our taps.
Taps for cast iron and titanium tapping are designed one GH class higher to provide better tool life.
For the special tolerance "7G", an oversize of approx. 2 x Au "G" has been taken into account.
Tolerance Chart - Metric Coarse / Fine
| Metric Coarse Thread |
Pitch | Tap Tolerance | Metric Fine Thread (choice) |
Tap Tolerance | ||
|---|---|---|---|---|---|---|
| 4H Tap | 6H Tap | 4H Tap | 6H Tap | |||
| M 1.6 | 0.35 | D2 | D2 / D3 | M 3 x 0.35 | D2 | D3 |
| M 1.8 | 0.35 | D2 | D2 / D3 | M 4 x 0.50 | D2 | D3 |
| M 2.0 | 0.40 | D2 | D3 | M 6 x 0.50 | D2 / D3 | D3 / D4 |
| M 2.2 | 0.45 | D2 | D3 | M 6 x 0.75 | D2 / D3 | D4 |
| M 2.5 | 0.45 | D2 | D3 | M 8 x 0.75 | D2 / D3 | D4 |
| M 3.0 | 0.50 | D2 | D3 | M 8 x 1.00 | D3 | D4 / D5 |
| M 3.5 | 0.60 | D2 | D3 / D4 | M 12 x 1.00 | D3 | D4 / D5 |
| M 4.0 | 0.70 | D2 / D3 | D3 / D4 | M 10 x 1.25 | D3 | D4 / D5 |
| M 4.5 | 0.75 | D2 / D3 | D3 / D4 | M 14 x 1.25 | D3 | D4 / D5 |
| M 5.0 | 0.80 | D2 / D3 | D3 / D4 | M 12 x 1.50 | D3 / D4 | D5 / D6 |
| M 6.0 | 1.00 | D2 / D3 | D4 / D5 | M 20 x 1.50 | D3 / D4 | D5 / D6 |
| M 7.0 | 1.00 | D2 / D3 | D4 / D5 | M 24 x 1.50 | D3 / D4 | D5 / D6 |
| M 8.0 | 1.25 | D3 | D4 / D5 | M 42 x 1.50 | D3 / D4 | D5 / D6 |
| M 10.0 | 1.50 | D3 | D4 / D5 | M 18 x 2.00 | D3 / D4 | D6 / D7 |
| M 12.0 | 1.75 | D3 / D4 | D5 / D6 | M 24 x 2.00 | D4 | D6 / D7 |
| M 14.0 | 2.00 | D3 / D4 | D5 / D6 | M 42 x 2.00 | D4 | D6 / D7 |
| M 16.0 | 2.00 | D3 / D4 | D5 / D6 | M 36 x 3.00 | D4 / D5 | D7 / D8 |
| M 18.0 | 2.50 | D4 | D6 / D7 | M 42 x 3.00 | D4 / D5 | D7 / D8 |
| M 20.0 | 2.50 | D4 | D6 / D7 | M 52 x 3.00 | D4 / D5 | D7 / D8 |
| M 22.0 | 2.50 | D4 | D6 / D7 | |||
| M 24.0 | 3.00 | D4 / D5 | D7 / D8 | |||
| M 27.0 | 3.00 | D4 / D5 | D7 / D8 | |||
| M 30.0 | 3.50 | D4 / D5 | D7 / D8 | |||
| M 33.0 | 3.50 | D4 / D5 | D8 / D9 | |||
| M 36.0 | 4.00 | D5 | D8 / D9 | |||
| M 39.0 | 4.00 | D5 | D8 / D9 | |||
| M 42.0 | 4.50 | D5 | D8 / D9 | |||
| M 45.0 | 4.50 | D5 | D8 / D9 | |||
| M 48.0 | 5.00 | D5 / D6 | D9 / D10 | |||
| M 52.0 | 5.00 | D5 / D6 | D9 / D10 | |||
Tolerance Chart - Oversize 6G Taps
Au "G" Values for Oversize Taps "6G Taps"
| Pitch | Tap Tolerance | |
|---|---|---|
| mm | inch | |
| 0.35 - 0.40 | 0.019 | .00075 |
| 0.45 - 0.50 | 0.020 | .00079 |
| 0.60 | 0.021 | .00083 |
| 0.70 - 0.75 | 0.022 | .00087 |
| 0.80 | 0.024 | .00094 |
| 1.00 | 0.026 | .0010 |
| 1.25 | 0.028 | .0011 |
| 1.50 | 0.032 | .0013 |
| 1.75 | 0.034 | .0013 |
| 2.00 | 0.038 | .0015 |
| 2.50 | 0.042 | .0017 |
| 3.00 | 0.048 | .0019 |
| 3.50 | 0.053 | .0021 |
| 4.00 | 0.060 | .0024 |
| 4.50 | 0.063 | .0025 |
| 5.00 | 0.071 | .0028 |
Photos
Social
Members
Newspaper
© 2012 Created by ArborIndustrial.
