Below is a table based on “ISO standard 68-1”. The table shows which size nut/bolt/drill should be used for a threaded rod of a given size. For example, if you have a pot magnet with a threaded bolt in size M3, you should use a nut with an internal thread diameter of 2.50 mm. In shops, the nut may also be called an “M3 nut”. By using the table, you ensure that the threaded rod and nut always fit together.
Thread Size Table
| Thread size | Pitch in mm | External thread | Tap drill |
|---|---|---|---|
| M2 | 0.40 | 2.0 | 1.6 |
| M3 | 0.50 | 3.0 | 2.50 |
| M4 | 0.70 | 4.0 | 3.30 |
| M5 | 0.80 | 5.0 | 4.20 |
| M6 | 1.00 | 6.00 | 5.00 |
| M7 | 1.00 | 7.0 | 6.00 |
| M8 | 1.25 | 8.0 | 6.80 |
| M10 | 1.50 | 10.0 | 8.50 |