A micrometer (micrometer screw gauge) is an instrument for precise measurement of small distances. The sleeve which moves the spindle by turning is graduated with marks 1/100 mm apart. One complete turn on the sleeve scale moves the spindle 0.5 mm.
The outside micrometer is the most commonly used type of micrometer.
It is used to measure external dimensions such as the outside diameter of an object.
Inside micrometers are used to measure inside dimensions like the inside diameter of a hole or tube.
There are two types of inside micrometer: caliper-type inside micrometers and tubular and rod inside micrometers.
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