Inches to MM Converter
How to convert inches to mm
To convert inches to millimeters, multiply the inch value by 25.4 (mm = in × 25.4), because 1 inch is defined as exactly 25.4 millimeters.
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| lengthConverter.units.inch | lengthConverter.units.mm |
|---|---|
| 1 | 25.4 |
| 5 | 127 |
| 10 | 254 |
| 25 | 635 |
| 50 | 1270 |
| 100 | 2540 |
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What are 1/4 inch and 3/8 inch in millimeters?
1/4 inch equals 6.35 mm and 3/8 inch equals 9.525 mm. That helps when a US screw, socket, or hex key size needs a metric substitute at a local hardware store.
Why convert a 5/16 drill bit or a 0.016 inch spec to mm?
A 5/16 inch drill bit is 7.9375 mm, and 0.016 inch is about 0.4064 mm. Those conversions are useful for imported part tolerances, CNC drawings, and 3D printing specs where your tools and stock are labeled in metric sizes.
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Inches to MM Converter
Use this direction when inch fractions appear on imported tools or parts, but the fasteners, cutters, drill bits, and shop inventory available to you are mostly metric.