Metric Bolt Sizes
ISO metric bolt sizes: pitch, major diameter, and tap drill size.
| Bolt | Pitch | Major Diameter | Tap Drill |
|---|---|---|---|
| M3 x 0.5 | 0.5 | 3 | 2.5 |
| M4 x 0.7 | 0.7 | 4 | 3.3 |
| M5 x 0.8 | 0.8 | 5 | 4.2 |
| M6 x 1.0 | 1 | 6 | 5 |
| M8 x 1.25 | 1.25 | 8 | 6.8 |
| M10 x 1.5 | 1.5 | 10 | 8.5 |
| M12 x 1.75 | 1.75 | 12 | 10.2 |
| M14 x 2.0 | 2 | 14 | 12 |
| M16 x 2.0 | 2 | 16 | 14 |
| M20 x 2.5 | 2.5 | 20 | 17.5 |
| M24 x 3.0 | 3 | 24 | 21 |
About this lookup
- What does "M8 x 1.25" mean?
- 8mm nominal diameter, 1.25mm thread pitch.
- Coarse vs fine pitch?
- Coarse (standard) pitch is shown. Fine pitch bolts have the same diameter but smaller pitch number.