Beneath you find the table with the required pre-drilling diameter for tapping metric thread
Nominal diameter | Pitch P | Drill diameter (mm) |
M3 | 0,50 | 2,50 |
M4 | 0,70 | 3,30 |
M5 | 0,80 | 4,20 |
M6 | 1,00 | 5,00 |
M8 | 1,25 | 6,75 (6,80) |
M10 | 1,50 | 8,50 |
M12 | 1,75 | 10,25 (10,50) |
M14 | 2,00 | 12,00 |
M16 | 2,00 | 14,00 |
M18 | 2,50 | 15,50 |
M20 | 2,50 | 17,50 |
M22 | 2,50 | 19,50 |
M24 | 3,00 | 21,00 |
Drill diameter = Nominal diameter - Pitch
Remark:
- Use a 6,80 mm drill for the theoretical drill diameter 6,75 mm.
- Use a 10,50 mm drill for the theoretical drill diameter 10,25 mm.