Screw Size Conversion Chart
- Gavin Leo
A screw size conversion chart is a valuable tool used in various fields such as engineering, construction, and manufacturing.
It allows for the conversion between metric and imperial screw sizes. This is crucial when working with components from different regions or with different manufacturing standards. For example, if you have a machine part that was designed using metric screws, but you need to replace a part with an imperial – sized equivalent (or vice – versa), the conversion chart helps you find the appropriate size.
Metric Screws and Their Approximate Imperial Equivalents
Metric
Imperial
| Diameter (mm) | Length (mm) | Nominal Size (Gauge) | Length (in) |
| 3 | 12 | 4 | 1/2 |
| 3 | 20 | 4 | 3/4 |
| 3 | 25 | 4 | 1 |
| 3.5 | 12 | 6 | 1/2 |
| 3.5 | 16 | 6 | 5/8 |
| 3.5 | 20 | 6 | 3/4 |
| 3.5 | 25 | 6 | 1 |
| 3.5 | 30 | 6 | 1 1/4 |
| 4 | 20 | 8 | 3/4 |
| 4 | 25 | 8 | 1 |
| 4 | 30 | 8 | 1 1/4 |
| 4 | 40 | 8 | 1 1/2 |
| 4 | 45 | 8 | 1 3/4 |
| 4 | 50 | 8 | 2 |
| 4 | 60 | 8 | 2 1/2 |
| 4 | 70 | 8 | 2 3/4 |
| 5 | 30 | 10 | 1 1/4 |
| 5 | 40 | 10 | 1 1/2 |
| 5 | 50 | 10 | 2 |
| 5 | 60 | 10 | 2 1/2 |
| 5 | 70 | 10 | 2 3/4 |
| 5 | 80 | 10 | 3 |
| 5 | 90 | 10 | 3 1/2 |
| 5 | 100 | 10 | 4 |
| 6 | 50 | 12 | 2 |
| 6 | 60 | 12 | 2 1/2 |
| 6 | 70 | 12 | 2 3/4 |
| 6 | 80 | 12 | 3 |
| 6 | 90 | 12 | 12 |
| 6 | 100 | 12 | 4 |