Metric thread coarse tapping drills.

The Metric (M) Thread has a parallel outside and inside diameter.
The thread angle is 60° and the thread depth is 0.614 x pitch.
Metric threads are referred to by a capital M, nominal outside diameter and pitch. For example M8 x 1.25.

Ø = diameter.
Pitch = the distance between threads, for example from the peak of one thread to the peak of the next.

Size mm Pitch mm Tapping Drill
Ø mm		 Clearance Drill
Ø mm
1.6 0.35 1.25 1.80
2 0.40 1.60 2.40
2.5 0.45 2.00 2.90
3 0.50 2.50 3.40
3.5 0.60 2.90 3.90
4 0.70 3.30 4.50
5 0.80 4.20 5.50
6 1.00 5.00 6.60
8 1.25 6.80 9.00
10 1.50 8.50 12.00
12 1.75 10.20 14.00
14 2.00 12.00 16.00
16 2.00 14.00 18.00
20 2.50 17.50 22.00
22 2.50 19.50 25.00
24 3.00 21.00 27.00
27 3.00 24.00 30.00
30 3.50 26.50 33.00
36 4.00 32.00 40.00
42 4.50 37.50 46.00
48 5.00 43.00 53.00
56 5.50 50.50 62.00
64 6.00 58.00 70.00