The drill bit diameter recommended in this table is for tapping processing , which can easily understand the drill bit diameter . It is selected according to the standard drill bit on the market. When the drill bit is used, due to the shape, size and accuracy of the drill bit, The material being drilled, etc., has a great influence on the size and accuracy of the drilled hole. Therefore, use the drill diameter in this table. If there is any improper point, the drill diameter should be changed appropriately in the actual situation. This table is based on the level 2 tooth Formulate.
| Metric coarse thread | |||
| specification | Standard diameter |
Grade 2 teeth drilling diameter
|
|
|
maximum
|
The smallest
|
||
| M1.0×0.25 | 0.75 |
0.785
|
0.729
|
| M1.1×0.25 | 0.85 |
0.885
|
0.829
|
| M1.2×0.25 | 0.95 |
0.985
|
0.929
|
| M1.4×0.3 | 1.10 |
1.142
|
1.075
|
| M1.6×0.35 | 1.25 |
1.321
|
1.221
|
| M1.7×0.35 |
1.35
|
1.421
|
1.321
|
| M1.8×0.35 |
1.45
|
1.521
|
1.421
|
| M2.0×0.4 |
1.60
|
1.679
|
1.567
|
| M2.2×0.45 |
1.75
|
1.838
|
1.713
|
| M2.3×0.4 |
1.90
|
1.979
|
1.867
|
| M2.5×0.45 |
2.10
|
2.138
|
2.013
|
| M2.6×0.45 |
2.20
|
2.238
|
2.113
|
| M3.0×0.5 |
2.50
|
2.599
|
2.459
|
| M3.0×0.6 |
2.40
|
2.44
|
2.280
|
| M3.5×0.6 |
2.90
|
3.010
|
2.850
|
| M4.0×0.7 |
3.30
|
3.422
|
3.242
|
| M4.0×0.75 |
3.25
|
3.326
|
3.106
|
| M4.5×0.75 |
3.80
|
3.878
|
3.688
|
| M5.0×0.8 |
4.20
|
4.334
|
4.134
|
| M5.0×0.9 |
4.10
|
4.170
|
3.930
|
| M6.0×1.0 |
5.00
|
5.153
|
4.917
|
| M7.0×1.0 |
6.00
|
6.153
|
5.917
|
| M8.0×1.25 |
6.80
|
6.912
|
6.647
|
| M9.0×1.25 |
7.80
|
7.912
|
7.647
|
| M10×1.5 |
8.50
|
8.676
|
8.376
|
| M11×1.5 |
9.50
|
9.676
|
9.376
|
| M12×1.75 |
10.30
|
10.441
|
10.106
|
| M14×2.0 |
12.00
|
12.210
|
11.735
|
| M16×2.0 |
14.00
|
14.210
|
13.835
|
| M18×2.5 |
15.50
|
15.744
|
15.294
|
| M20×2.5 |
17.50
|
17.744
|
17.294
|
| M22×2.5 |
19.50
|
19.744
|
19.294
|
| M24×3.0 |
21.00
|
21.252
|
2.752
|
| M27×3.0 |
24.00
|
24.252
|
23.752
|
| M30×3.5 |
26.50
|
26.771
|
26.211
|
| Metric fine thread | |||
| specification | Standard diameter |
Grade 2 teeth drilling diameter
|
|
|
maximum
|
The smallest
|
||
| M1.0×0.2 | 0.80 |
0.821
|
0.783
|
| M1.1×0.2 | 0.90 |
0.921
|
0.883
|
| M1.2×0.2 | 1.00 |
1.021
|
0.983
|
| M1.4×0.2 | 1.20 |
1.221
|
0.183
|
| M1.6×0.2 | 1.40 |
1.421
|
1.383
|
| M1.7×0.2 |
1.45
|
1.500
|
1.460
|
| M1.8×0.2 |
1.60
|
1.621
|
1.583
|
| M2.0×0.25 |
1.75
|
1.785
|
1.729
|
| M2.2×0.25 |
1.95
|
1.985
|
1.929
|
| M2.3×0.25 |
2.05
|
2.061
|
2.001
|
| M2.5×0.35 |
2.20
|
2.221
|
2.121
|
| M2.6×0.35 |
2.20
|
2.246
|
2.186
|
| M3.0×0.35 |
2.70
|
2.721
|
2.621
|
| M3.5×0.35 |
3.20
|
3.221
|
3.121
|
| M4.0×0.5 |
3.50
|
3.599
|
3.459
|
| M4.5×0.5 |
4.00
|
4.099
|
3.959
|
| M5×0.5 |
4.50
|
4.599
|
4.459
|
| M5.5×0.5 |
5.00
|
5.099
|
4.959
|
| M6.0×0.75 |
5.30
|
5.378
|
5.188
|
| M6.0×0.5 |
5.50
|
5.550
|
5.400
|
| M7.0×0.75 |
6.30
|
6.378
|
61.88
|
| M7.0×0.5 |
6.50
|
6.550
|
64.00
|
| M8.0×1.0 |
7.00
|
7.153
|
6.917
|
| M8.0×0.75 |
7.30
|
7.378
|
7.188
|
| M8×0.5 |
7.50
|
7.520
|
7.400
|
| M9×1.0 |
8.00
|
8.153
|
7.917
|
| M9×0.75 |
8.30
|
8.378
|
8.188
|
| M10×1.25 |
8.80
|
8.912
|
8.647
|
| M10×1.0 |
9.00
|
9.153
|
8.917
|
| M10×0.75 |
9.30
|
9.378
|
9.188
|
| M10×0.5 |
9.50
|
9.520
|
9.400
|
| M11×1.0 |
10.00
|
10.153
|
9.917
|
| M11×0.75 |
10.30
|
10.378
|
10.188
|
| M11×1.5 |
10.50
|
10.676
|
10.376
|
| M12×1.25 |
10.80
|
10.912
|
10.647
|
| Metric fine thread | |||
| specification | Standard diameter |
Grade 2 teeth drilling diameter
|
|
|
maximum
|
The smallest
|
||
| M12×1.0 | 11.00 |
11.153
|
10.917
|
| M12×0.5 | 11.50 |
11.520
|
11.4
|
| M14×1.5 | 12.50 |
12.676
|
12.376
|
| M14×1.0 | 13.00 |
13.153
|
12.917
|
| M15×1.5 | 13.50 |
13.676
|
13.376
|
| M15×1.0 |
14.00
|
14.153
|
13.917
|
| M16×1.5 |
14.50
|
14.676
|
14.376
|
| M16×1.0 |
15.00
|
15.153
|
14.917
|
| M17×1.5 |
15.50
|
15.676
|
15.376
|
| M17×1.0 |
16.00
|
16.153
|
15.917
|
| M18×2.0 |
16.00
|
16.210
|
15.835
|
| M18×1.5 |
16.50
|
16.670
|
16.376
|
| M18×1.0 |
17.00
|
17.153
|
16.917
|
| M20×2.0 |
18.00
|
18.210
|
17.835
|
| M20×1.5 |
18.50
|
18.676
|
18.376
|
| M20×1.0 |
19.00
|
19.153
|
18.917
|
| M20×2.0 |
20.00
|
20.210
|
19.835
|
| M22×1.5 |
20.50
|
20.676
|
20.376
|
| M22×1.0 |
21.00
|
21.153
|
20.917
|
| M24×2.0 |
22.00
|
22.210
|
21.835
|
| M24×1.5 |
22.50
|
22.676
|
22.376
|
| M24×1.0 |
23.00
|
23.153
|
22.917
|
| M25×2.0 |
23.00
|
23.210
|
22.835
|
| M25×1.5 |
23.50
|
23.676
|
23.376
|
| M25×1.0 |
24.00
|
24.153
|
23.917
|
| M26×1.5 |
24.50
|
24.676
|
24.376
|
| M27×2.0 |
25.00
|
25.210
|
24.835
|
| M27×1.5 |
25.50
|
25.676
|
25.376
|
| M27×1.0 |
26.00
|
26.153
|
25.917
|
| M28×2.0 |
26.00
|
26.210
|
25.835
|
| M28×1.5 |
26.50
|
26.676
|
26.376
|
| M28×1.0 |
27.00
|
27.153
|
26.917
|
| M30×3.0 |
27.00
|
27.252
|
26.752
|
| M30×2.0 |
28.00
|
28.210
|
27.835
|
| M30×1.5 |
28.50
|
28.676
|
28.376
|
| M30×1.0 |
29.00
|
29.153
|
28.917
|
| M32×2.0 |
30.00
|
30.210
|
29.835
|
| M32×1.5 |
30.50
|
30.676
|
30.376
|
| M33×3.0 |
30.00
|
30.252
|
29.752
|
| M33×2.0 |
31.00
|
31.210
|
30.835
|
| M33×1.5 |
31.50
|
31.376
|
31.376
|
| M35×1.5 |
33.50
|
33.676
|
33.376
|
| M36×3.0 |
33.00
|
33.252
|
32.752
|
| M36×2.0 |
34.00
|
34.210
|
33.835
|
| M36×1.5 |
34.50
|
34.676
|
34.376
|
| American fine thread | |||
| Specification (UNF) | Standard diameter |
Grade 2 teeth drilling diameter
|
|
|
maximum
|
The smallest
|
||
| Number of teeth outside diameter | |||
| NO.0-80(1.524) |
1.25
|
1.305
|
1.182
|
| NO.1-72(1.854) |
1.55
|
1.612
|
1.474
|
| NO.2-64(2.184) |
1.85
|
1.912
|
1.756
|
| NO.3-56(2.515) |
2.10
|
2.197
|
2.025
|
| NO.4-48(2.845) |
2.40
|
2.458
|
2.271
|
| NO.5-44(3.175) | 2.70 | 2.740 | 2.551 |
| NO.6-40(3.505) | 2.90 | 3.022 | 2.820 |
| NO.8-36(4.166) | 3.50 | 3.606 | 3.404 |
| NO.10-32(4.826) | 4.10 | 4.165 | 3.963 |
| NO.12-28(5.846) | 4.60 | 4.724 | 4.496 |
| 1/4 -28 | 5.50 | 5.588 | 5.360 |
| 5/16 -24 | 6.90 | 7.035 | 6.782 |
| 3/8 -24 | 8.50 | 8.636 | 8.382 |
| 7/16 -20 | 9.90 | 10.033 | 9.729 |
| 1/2 -20 | 11.50 | 11.607 | 11.329 |
| 9/16 -18 | 12.90 | 13.081 | 12.751 |
| 5/8 -18 | 14.50 | 14.681 | 14.351 |
| 3/4 -16 | 17.50 | 14.678 | 17.323 |
| 7/8 -14 | 20.50 | 20.675 | 20.270 |
| 1 -12 | 23.20 | 23.571 | 23.114 |
| 1-1/8 -12 |
26.50
|
26.746 | 26.289 |
| 1-1/4 -12 |
29.50
|
29.921 | 29.464 |
| 1-3/8 -12 |
32.80
|
33.096 | 32.464 |
| 1-1/2 -12 |
36.00
|
36.270 | 35.814 |
| Chipless wire tap drilling diameter | |||
| specification |
Accuracy class
|
||
|
RH4.5.6
|
RH7.8
|
RH9
|
|
| M1.0×0.25 | 0.86 |
0.88
|
– |
| M1.1×0.25 | 0.96 |
0.98
|
– |
| M1.2×0.25 | 1.06 |
1.08
|
– |
| M1.4×0.3 | 1.24 |
1.25
|
– |
| M1.6×0.35 | 1.41 |
1.43
|
– |
| M1.7×0.35 |
1.51
|
1.53
|
– |
| M1.8×0.35 |
1.61
|
1.63
|
– |
| M2.0×0.4 |
1.78
|
1.80
|
– |
| M2.2×0.45 |
1.95
|
1.98
|
– |
| M2.3×0.4 |
2.08
|
2.10
|
– |
| M2.5×0.45 |
2.25
|
2.28
|
–
|
| M2.6×0.45 |
2.35
|
1.38
|
–
|
| M3.0×0.5 |
2.73
|
2.75
|
–
|
| M3.0×0.6 |
3.17
|
3.20
|
–
|
| M4.0×0.7 |
3.62
|
3.65
|
3.69
|
| M5.0×0.8 |
4.56
|
4.60
|
4.64
|
| M6.0×1.0 |
5.45
|
5.50
|
5.55
|
| M7.0×1.0 |
6.45
|
6.50
|
6.55
|
| M8.0×1.25 |
7.31
|
7.38
|
7.44
|
| M10×1.5 |
9.18
|
9.25
|
9.32
|
| M10×1.25 |
9.31
|
9.38
|
9.44
|
| M12×1.75 |
11.04
|
11.12
|
11.21
|
| M12×1.25 |
11.31
|
11.38
|
11.44
|
| Note: The drilling diameter of the non-grooved wire tap is the value listed in the above table. Due to the influence of the material, hardness, shape, size, etc. of the processed material, it will vary somewhat. Therefore, please refer to the above table at the same time. Increase or decrease several. | |||
| American pipe thread | |||
| Specification (UNEF) | Standard diameter |
Grade 2 teeth drilling diameter
|
|
|
maximum
|
The smallest
|
||
| NO.12 -32 | 4.70 | 4.826 | 4.623 |
| 1/4 -32 | 5.60 | 5.690 | 5.486 |
| 5/16 -32 | 7.10 | 7.264 | 7.087 |
| 3/8 -32 | 8.70 | 8.865 | 8.661 |
| 7/16 -28 | 10.20 | 10.338 | 10.135 |
| 1/2 -28 | 11.80 | 11.938 | 11.709 |
| 9/16 -28 | 13.20 | 13.386 | 13.132 |
| 5/8 -24 | 14.80 | 14.986 | 14.732 |
| 3/4 -20 | 17.80 | 17.958 | 17.678 |
| 7/8 -20 | 21.00 | 21.133 | 20.853 |
| 1 -20 | 24.00 | 24.308 | 24.028 |