Thread | TPI | Major Dia. | Pitch | Tapping Drill | |
---|---|---|---|---|---|
0 | 25.4 | 6.0mm | 1.00mm | No. 5 | 5.1mm |
1 | 28.2 | 5.3mm | 0.9mm | No. 14 | 4.5mm |
2 | 31.3 | 4.7mm | 0.81mm | No. 22 | 4.0mm |
3 | 34.8 | 4.1mm | 0.73mm | No. 29 | 3.45mm |
4 | 38.5 | 3.60mm | 0.66mm | No. 31 | 3.00mm |
5 | 43.1 | 3.20mm | 0.59mm | No. 36 | 2.65mm |
6 | 47.9 | 2.8mm | 0.53mm | No. 41 | 2.30mm |
7 | 52.9 | 2.5mm | 0.48mm | No. 45 | 2.05mm |
8 | 59.1 | 2.2mm | 0.43mm | No. 49 | 1.80mm |
9 | 65.1 | 1.9mm | 0.39mm | No. 52 | 1.55mm |
10 | 72.6 | 1.7mm | 0.35mm | No. 54 | 1.40mm |
11 | 81.9 | 1.5mm | 0.31mm | 3/64″ | 1.20mm |
12 | 90.7 | 1.3mm | 0.28mm | No. 57 | 1.05mm |
13 | 102.0 | 1.2mm | 0.25mm | N0. 60 | 0.975mm |
14 | 110.0 | 1.0mm | 0.23mm | No. 66 | 0.775mm |
Sourced from http://www.royalsignals.org.uk/articles/threads.htm