Threads
You can add a helicoil, a coiled typically steel wire, to repair broken/stripped threads in softer materials like aluminum/plastic (saw on youtube)
Screw sizes
Most common:
- #6-32, M3 electronics
- #8, M4 universal
- 1/4-20, M5/M6 structural (common on bikes)
| Imperial Size | Major Diameter (in) | Major Diameter (mm) | Closest Metric |
|---|---|---|---|
| #0 | 0.0600 | 1.52 | M1.6 |
| #1 | 0.0730 | 1.85 | M2 |
| #2 | 0.0860 | 2.18 | M2.2 |
| #3 | 0.0990 | 2.51 | M2.5 |
| #4 | 0.1120 | 2.84 | M3 |
| #5 | 0.1250 | 3.18 | M3.5 |
| #6 | 0.1380 | 3.51 | M3.5–M4 |
| #8 | 0.1640 | 4.17 | M4 |
| #10 | 0.1900 | 4.83 | M5 |
| #12 | 0.2160 | 5.49 | M5.5 |
| 1/4" | 0.2500 | 6.35 | M6 |
| 5/16" | 0.3125 | 7.94 | M8 |
| 3/8" | 0.3750 | 9.53 | M10 |
| 7/16" | 0.4375 | 11.11 | M11 |
| 1/2" | 0.5000 | 12.70 | M12 |
| 5/8" | 0.6250 | 15.88 | M16 |
| 3/4" | 0.7500 | 19.05 | M20 |
*outside of major threads
Thread types
- Coarse (most common)
- Fine
- higher strength
- vibration resistence
- Extra fine (rare)