Micrometers

 

— measuring instruments designed to determine linear dimensions with high accuracy — usually up to 0.01 mm. Note that this category includes both micrometers of traditional design and "caliper-micrometers" that have a similar measurement accuracy. For more information about the latter, see "calipers"; here we will consider micrometers with a classic device.

Such devices outwardly resemble clamps — their design is based on a characteristic bracket with a clamping screw. The fundamental difference from vernier calipers is also that in this case the movable part does not move freely, but moves due to the rotation of a precision screw (“micrometer” — according to the name of the device). It is precisely because of this that the high positioning accuracy of the measuring jaws and the possibility of measurements with a very small division value are ensured (even with a mechanical principle of operation, without the use of electronics). However, the travel of the moving part usually does not exceed 25 mm, due to which micrometers of different sizes may be required for different situations; see "Length" for details.

Also note that classic micrometers are intended only for measuring external dimensions; for high-precision internal measurements, specialized devices are used — inside gauges (they are classified in our catalog in the "Other hand tools" section).

Micrometers can be mechanical or digital; for details, see "Type of caliper" — this list is also relevant for this type of instrument.