A micrometer sometimes known as a micrometer screw gauge, is a device incorporating a calibrated screw

Screw

A screw, or bolt, is a type of fastener characterized by a helical ridge, known as an external thread or just thread, wrapped around a cylinder. Some screw threads are designed to mate with a complementary thread, known as an internal thread, often in the form of a nut or an object that has the...

 used widely for precise measurement of small distances in mechanical engineering

Mechanical engineering

Mechanical engineering is a discipline of engineering that applies the principles of physics and materials science for analysis, design, manufacturing, and maintenance of mechanical systems. It is the branch of engineering that involves the production and usage of heat and mechanical power for the...

 and machining

Machining

Conventional machining is a form of subtractive manufacturing, in which a collection of material-working processes utilizing power-driven machine tools, such as saws, lathes, milling machines, and drill presses, are used with a sharp cutting tool to physical remove material to achieve a desired...

 as well as most mechanical trades, along with other metrological

Metrology

Metrology is the science of measurement. Metrology includes all theoretical and practical aspects of measurement. The word comes from Greek μέτρον , "measure" + "λόγος" , amongst others meaning "speech, oration, discourse, quote, study, calculation, reason"...

 instruments such as dial, vernier, and digital calipers. Micrometers are often, but not always, in the form of caliper

Caliper

A caliper is a device used to measure the distance between two opposing sides of an object. A caliper can be as simple as a compass with inward or outward-facing points...

s.

Colloquially the word micrometer is often shortened to mike /ˈmaɪk/ .
The word micrometer is a neoclassical coinage from Greek micros, "small", and metron, "measure".