Standard Thread Sizes for CNC Machining
Thread charts for the most common metric and imperial sizes used in CNC milling and turning.
Metric Coarse (ISO 965)
| Thread Size | Pitch (mm) | Tap Drill (mm) |
|---|---|---|
| M3 x 0.5 | 0.5 | 2.5 |
| M4 x 0.7 | 0.7 | 3.3 |
| M5 x 0.8 | 0.8 | 4.2 |
| M6 x 1.0 | 1.0 | 5.0 |
| M8 x 1.25 | 1.25 | 6.8 |
| M10 x 1.5 | 1.5 | 8.5 |
Unified National Coarse (UNC)
| Thread Size | TPI | Tap Drill (mm) |
|---|---|---|
| #4-40 | 40 | 2.25 |
| #6-32 | 32 | 2.85 |
| #10-24 | 24 | 3.90 |
| 1/4-20 | 20 | 5.10 |
| 3/8-16 | 16 | 8.00 |