Converting between millimeters (mm) and inches (in) for socket sizes is quite common when working with tools and fasteners. Here is a quick overview of the mm to in conversion for sockets along with some examples.
Quick Conversion Factors
Here are the key conversion factors to keep in mind:
- 1 mm = 0.03937 in
- 1 in = 25.4 mm
So to convert:
- From mm to in: Divide by 25.4
- From in to mm: Multiply by 25.4
Examples
Let’s look at some examples of converting specific socket sizes:
| Millimeters | Inches |
|---|---|
| 10 mm | 10 / 25.4 = 0.3937 in |
| 13 mm | 13 / 25.4 = 0.5118 in |
| 17 mm | 17 / 25.4 = 0.6693 in |
And going the other way:
| Inches | Millimeters |
|---|---|
| 1/4 in | 1/4 * 25.4 = 6.35 mm |
| 3/8 in | 3/8 * 25.4 = 9.525 mm |
| 1/2 in | 1/2 * 25.4 = 12.7 mm |
Metric and SAE Sockets
It’s worth noting that sockets come in metric and SAE (Society of Automotive Engineers) sizes:
- Metric sockets are based on mm sizes (10mm, 11mm, 12mm, etc.)
- SAE sockets use fractional inches sizes (1/4 in, 3/8 in, 1/2 in, etc.)
So a 10mm socket is a bit smaller than a 3/8 in socket. Converting between the two systems is common when working with mixed fasteners or tools.
Thousandths of an Inch
Socket sizes are sometimes specified to the thousandth of an inch. Some examples:
| Thousandths | Decimal Inches |
|---|---|
| 325 | 0.325 in |
| 675 | 0.675 in |
| 875 | 0.875 in |
To convert the thousandths to a decimal measurement, simply divide by 1000. And to go the other way, multiply the decimal inches by 1000.
Conclusion
Converting between mm and inches is straightforward using the conversion factors of 25.4 mm per inch and 0.03937 inches per mm. Keeping those handy allows for quick conversions between metric and SAE socket systems. Pay attention to whether a size is specified in mm, fractional inches, or thousandths of an inch. With some practice, socket size conversions can become second nature!