Thousandth of an inch

Thousandth of an inch
ID-1 cards like payment cards have a thickness of 0.03 inches (30 thou).
General information
Unit systemImperial/US units
Unit ofLength
Symbolthou, mil
Conversions
1 thou in ...... is equal to ...
   imperial/US units   0.001 in
   SI units   25.4 μm

A thousandth of an inch is a derived unit of length in a system of units using inches. Equal to 11000 of an inch, a thousandth is commonly called a thou /ˈθ/ (used for both singular and plural) or, particularly in North America, a mil (plural mils).

The words are shortened forms of the English and Latin words for "thousand" (mille in Latin). In international engineering contexts, confusion can arise because mil is a formal unit name in North America but mil or mill is also a common colloquial clipped form of millimetre.[1] The units are considerably different: a millimetre is approximately 39 mils.

  1. ^ "mil". Lexico UK English Dictionary. Oxford University Press. Archived from the original on July 13, 2021.