Micrometer

A micrometer ( /maɪˈkrɒmɨtər/ US dict: mī·krŏm′·ĭ·tər), sometimes known as a micrometer screw gauge, is a device incorporating a calibrated screw used widely for precise measurement of small distances in mechanical engineering and machining as well as most mechanical trades, along with other metrological instruments such as dial, vernier, and digital calipers. Micrometers are often, but not always, in the form of calipers.