Screws - Metric vs. Inches
Metric screws and their approximately imperial equivalents:
| Metric | Imperial | ||
|---|---|---|---|
| Diameter (mm) | Length (mm) | Nominal Size no. | 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 | 3 1/2 |
| 6 | 100 | 12 | 4 |
Example from the table: M4 x 60 equals approximately to #8 x 2 1/2
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