Metric Tap Drill Sizes
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Find the correct drill size prior to using a thread tap. Suitable for Masonry, Wood and Metal Balustrade, Trellis and Catenary Systems
Metric Fine Sizes | Metric Coarse Sizes | ||
Tap Size (mm) | Drill Size (mm) | Tap Size (mm) | Drill Size (mm) |
4 x 0.35 | 3.6 | 1 x 0.25 | 0.75 |
4 x 0.5 | 3.5 | 1.1 x 0.25 | 0.85 |
5 x 0.5 | 4.5 | 1.2 x .25 | 0.95 |
6 x 0.5 | 5.5 | 1.4 x 0.3 | 1.1 |
6 x 0.75 | 5.25 | 1.6 x 0.35 | 1.25 |
7 x 0.75 | 6.25 | 1.7 x 0.35 | 1.3 |
8 x 0.5 | 7 | 1.8 x 0.35 | 1.45 |
8 x 0.75 | 7.25 | 2 x 0.4 | 1.6 |
8 x 1 | 7 | 2.2 x 0.45 | 1.75 |
9 x 1 | 8 | 2.5 x 0.45 | 2 |
10 x 0.75 | 9.25 | 3 x 0.5 | 2.5 |
10 x 1 | 9 | 3.5 x 0.6 | 2.9 |
10 x 1.25 | 8.8 | 4 x 0.7 | 3.3 |
11 x 1 | 10 | 4.5 x 0.75 | 3.7 |
12 x 0.75 | 11.25 | 5 x 0.8 | 4.2 |
12 x 1 | 11 | 6 x 1 | 5 |
12 x 1.5 | 10.5 | 7 x 1 | 6 |
14 x 1 | 13 | 8 x 1.25 | 6.8 |
14 x1.25 | 12.8 | 9 x 1.25 | 7.8 |
14 x 1.5 | 12.5 | 10 x 1.5 | 8.5 |
16 x 1 | 15 | 11 x 1.5 | 9.5 |
16 x 1.5 | 14.5 | 12 x 1.75 | 10.2 |
18 x 1 | 17 | 14 x 2 | 12 |
18 x 2 | 16 | 16 x 2 | 14 |
20 x 1 | 19 | 18 x 2.5 | 15.5 |
20 x 1.5 | 18.5 | 20 x 2.5 | 17.5 |
20 x 2 | 18 | 22 x 2.5 | 19.5 |
22 x 1 | 21 | 24 x 3 | 21 |
22 x 1.5 | 20.5 | 27 x 3 | 24 |
22 x 2 | 20 | 30 x 3.5 | 26.5 |
24 x 1.5 | 22.5 | 33 x 3.5 | 29.5 |
24 x 2 | 22 | 36 x 4 | 32 |
26 x 1.5 | 24.5 | 39 x 4 | 35 |
27 x 1.5 | 25.5 | ||
27 x 2 | 25 | ||
28 x 1.5 | 26.5 | ||
30 x 1.5 | 28.5 | ||
30 x 2 | 28 | ||
33 x 2 | 31 | ||
36 x 3 | 33 | ||
39 x 3 | 36 | ||
Tip: To calculate the tap drill size for metric threads the diameter of | |||
thread minus the thread pitch will give you the required tap drill size. | |||
e.g. for M6 x 1 thread size 6 - 1 = 5mm so use a 5mm drill. |
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