Convert Millimeters to Thou
Convert Millimeters (mm) to Thou (th) instantly and accurately.
Conversion Formula
th = mm × 39.37007874
About Millimeters
A millimeter (mm) is one thousandth of a meter, making it the smallest unit commonly used in everyday measurements. To visualize this, a credit card is about 1 mm thick, and a paperclip wire is roughly 1 mm in diameter. Millimeters are essential in engineering, manufacturing, and medicine for precise measurements. Rainfall is measured in millimeters, with 1 mm representing a very light drizzle. Most rulers and measuring tapes include millimeter markings for accuracy.
About Thou
A thou (also called mil) is one thousandth of an inch, equal to 0.0254 millimeters or 25.4 micrometers. This unit is commonly used in engineering and manufacturing in countries that use imperial measurements, particularly for specifying tolerances, wire gauges, and thin material thicknesses. For example, a standard plastic bag might be 1-2 thou thick, a sheet of paper is about 4 thou, and precision machined parts often have tolerances measured in thou. Electronic circuit board copper traces are typically 1.4 thou thick.
Quick Reference Table
| Millimeters (mm) | Thou (th) |
|---|---|
| 1 mm | 39.3701 th |
| 2 mm | 78.7402 th |
| 5 mm | 196.85 th |
| 10 mm | 393.701 th |
| 25 mm | 984.252 th |
| 50 mm | 1968.5 th |
| 100 mm | 3937.01 th |