METRIC TAP DRILL CHART
Metric tap drill chart according to ISO 2306:1972 standard for ISO metric
threads. Dimension are in millimetres.
|
Coarse Pitch Thread |
Drill size (mm) |
Tap Size |
Basic Major
Dia. |
Thread Pitch |
Minor diameter for class |
5H
max. |
6H max. |
7H max. |
5H, 6H, 7H min |
M1.6 x 0.35 |
1.6 |
0.35 |
1.301 |
1.321 |
- |
1.221 |
1.25 |
M2 x 0.4 |
2 |
0.4 |
1.657 |
1.679 |
- |
1.567 |
1.60 |
M2.5 x 0.45 |
2.5 |
0.45 |
2.113 |
2.138 |
- |
2.013 |
2.05 |
M3 x 0.5 |
3 |
0.5 |
2.571 |
2.599 |
2.639 |
2.459 |
2.50 |
M3.5* x 0.6 |
3.5 |
0.6 |
2.975 |
3.010 |
3.050 |
2.850 |
2.90 |
M4 x 0.7 |
4 |
0.7 |
3.382 |
3.422 |
3.466 |
3.242 |
3.30 |
M5 x 0.8 |
5 |
0.8 |
4.294 |
4.334 |
4.384 |
4.134 |
4.20 |
M6 x 1 |
6 |
1 |
5.107 |
5.153 |
5.217 |
4.917 |
5.00 |
M8 x 1.25 |
8 |
1.25 |
6.859 |
6.912 |
6.982 |
6.647 |
6.80 |
M10 x 1.5 |
10 |
1.5 |
8.612 |
8.676 |
8.751 |
8.376 |
8.50 |
M12 x 1.75 |
12 |
1.75 |
10.371 |
10.441 |
10.531 |
10.106 |
10.20 |
M14* x 2 |
14 |
2 |
12.135 |
12.210 |
12.310 |
11.835 |
12.00 |
M16 x 2 |
16 |
2 |
14.135 |
14.210 |
14.310 |
13.835 |
14.00 |
M18* x 2.5 |
18 |
2.5 |
15.649 |
15.744 |
15.854 |
15.294 |
15.50 |
M20 x 2.5 |
20 |
2.5 |
17.649 |
17.744 |
17.854 |
17.294 |
17.50 |
M22* x 2.5 |
22 |
2.5 |
19.649 |
19.744 |
19.854 |
19.294 |
19.50 |
M24 x 3 |
24 |
3 |
21.152 |
21.252 |
21.382 |
20.752 |
21.00 |
M27* x 3 |
27 |
3 |
24.152 |
24.252 |
24.382 |
23.752 |
24.00 |
M30 x 3.5 |
30 |
3.5 |
26.661 |
26.771 |
26.921 |
26.211 |
26.50 |
M33* x 3.5 |
33 |
3.5 |
29.661 |
29.771 |
29.921 |
29.211 |
29.50 |
M36 x 4 |
36 |
4 |
32.145 |
32.270 |
32.420 |
31.670 |
32.00 |
M39* x 4 |
39 |
4 |
35.145 |
35.270 |
35.420 |
34.670 |
35.00 |
M42 x 4.5 |
42 |
4.5 |
37.659 |
37.799 |
37.979 |
37.129 |
37.50 |
M45* x 4.5 |
45 |
4.5 |
40.659 |
40.799 |
40.979 |
40.129 |
40.50 |
M48 x 5 |
48 |
5 |
43.147 |
43.297 |
43.487 |
42.587 |
43.00 |
M52* x 5 |
52 |
5 |
47.147 |
47.297 |
47.487 |
46.587 |
47.00 |
M56 x 5.5 |
56 |
5.5 |
50.646 |
50.796 |
50.996 |
50.046 |
50.50 |
Note : * Non-preferred threads according to standard.
Fine Pitch Thread |
Drill size (mm) |
Tap Size |
Basic Major
Dia. |
Thread Pitch |
Minor diameter for class |
5H
max. |
6H max. |
7H max. |
5H, 6H, 7H min |
M8 x 1 |
8 |
1 |
7.107 |
7.153 |
7.217 |
6.917 |
7.00 |
M10 x 1 |
10 |
1 |
9.107 |
9.153 |
9.217 |
8.917 |
9.00 |
M10* x 1.25 |
10 |
1.25 |
8.859 |
8.912 |
8.982 |
8.647 |
8.80 |
M12* x 1.25 |
12 |
1.25 |
10.859 |
10.912 |
10.982 |
10.647 |
10.80 |
M12 x 1.5 |
12 |
1.5 |
10.612 |
10.676 |
10.751 |
10.376 |
10.50 |
M14* x 1.5 |
14 |
1.5 |
12.612 |
12.676 |
12.751 |
12.376 |
12.50 |
M16 x 1.5 |
16 |
1.5 |
14.612 |
14.676 |
14.751 |
14.376 |
14.50 |
M18* x 1.5 |
18 |
1.5 |
16.612 |
16.676 |
16.751 |
16.376 |
16.50 |
M20 x 1.5 |
20 |
1.5 |
18.612 |
18.676 |
18.751 |
18.376 |
18.50 |
M20* x 2 |
20 |
2 |
18.135 |
18.210 |
18.310 |
17.835 |
18.00 |
M22* x 1.5 |
22 |
1.5 |
20.612 |
20.676 |
20.751 |
20.376 |
20.50 |
M24 x 2 |
24 |
2 |
22.135 |
22.210 |
22.310 |
21.835 |
22.00 |
M27* x 2 |
27 |
2 |
25.135 |
25.210 |
25.310 |
24.835 |
25.00 |
M30 x 2 |
30 |
2 |
28.135 |
28.210 |
28.310 |
27.835 |
28.00 |
M33* x 2 |
33 |
2 |
31.135 |
31.210 |
31.310 |
30.835 |
31.00 |
M36 x 3 |
36 |
3 |
33.152 |
33.252 |
33.382 |
32.752 |
33.00 |
M39* x 3 |
39 |
3 |
36.152 |
36.252 |
36.382 |
36.752 |
36.00 |
M42 x 3 |
42 |
3 |
39.152 |
39.252 |
39.382 |
38.752 |
39.00 |
M45* x 3 |
45 |
3 |
42.152 |
42.252 |
42.382 |
41.752 |
42.00 |
M48 x 3 |
48 |
3 |
45.152 |
45.252 |
45.382 |
44.752 |
45.00 |
M52* x 4 |
52 |
4 |
48.145 |
48.270 |
48.420 |
47.670 |
48.00 |
Note : * Non-preferred threads according to standard.
Supplements:
Reference:
- ISO 68-1:1998(E) - ISO general purpose screw threads — Basic profile — Part 1: Metric screw threads
-
ISO 2306:1972, Drills for use prior to tapping screw threads