Editing Micrometer (device) (section)

==Parts==
[[File:Micrometer.svg|thumb|none|500px|
Diagram of a micrometer showing a measurement of 7.145&nbsp;mm ± 0.005&nbsp;mm]]

A micrometer is composed of:

{{ordered list
| '''Anvil''': The shiny part that the spindle moves toward, and that the sample rests against.
| '''Spindle''': The shiny cylindrical component that the thimble causes to move toward the anvil.
| '''Ratchet stop''': Device on end of handle that limits applied pressure by slipping at a calibrated torque.
| '''Sleeve, barrel, or stock''': The stationary round component with the linear scale on it, sometimes with vernier markings. In some instruments the scale is marked on a tight-fitting but movable cylindrical sleeve fitting over the internal fixed barrel. This allows zeroing to be done by slightly altering the position of the sleeve.<ref>{{cite web|last1=Waitelet|first1=Ermand L.|title=Micrometer with adjustable barrel sleeve. US 3131482 A|url=https://patents.google.com/patent/US3131482|website=Google patents|access-date=26 August 2016|date=1964}}</ref><ref>{{cite web |title=Precision Measuring and Gaging |url=http://www.waybuilder.net/sweethaven/mechtech/mfgtech/precmeasuring/default.asp?iNum=0203&uNum=2 |website=www.waybuilder.net |archive-url=https://web.archive.org/web/20160828150134/http://www.waybuilder.net/sweethaven/mechtech/mfgtech/precmeasuring/default.asp?iNum=0203&uNum=2 |archive-date=28 August 2016 |url-status=dead }}</ref>
| '''Frame''': The C-shaped body that holds the anvil and barrel in constant relation to each other. It is thick because it needs to minimize flexion, expansion, and contraction, which would distort the measurement.{{paragraph}}The frame is heavy and consequently has a high thermal mass, to prevent substantial heating up by the holding hand/fingers. It is often covered by insulating plastic plates which further reduce heat transference. Explanation: if one holds the frame long enough so that it heats up by 10&nbsp;°C, then the increase in length of any 10&nbsp;cm linear piece of steel is of magnitude 1/100&nbsp;mm. For micrometers this is their typical accuracy range. Micrometers typically have a specified temperature at which the measurement is correct (often 20&nbsp;°C [68&nbsp;°F], which is generally considered "[[room temperature]]" in a room with [[HVAC]]). [[Toolroom]]s are generally kept at 20&nbsp;°C [68&nbsp;°F].
| '''Thimble scale''': Rotating graduated markings.
| '''Lock nut, lock-ring, or thimble lock''': The knurled component (or lever) that one can tighten to hold the spindle stationary, such as when momentarily holding a measurement.
| '''Thimble''': The component that one's thumb turns.
| '''Screw''': (Not visible) The heart of the micrometer, as explained under [[#Operating principles|"Operating principles"]]. It is inside the barrel. This references the fact that the usual name for the device in German is ''Messschraube'', literally "measuring screw".
}}