Rotor
Also called winding rotor
The rotor is the weighted, pivoting semicircle in an automatic movement that swings as the wearer moves and winds the mainspring.
On watches with a display caseback, the rotor is often decorated and is one of the first things a buyer sees. A rotor that is noisy, loose, or scraping the inside of the case can point to worn bearings or a service need.
Gently rock an automatic watch and listen. A smooth, quiet rotor is a good sign; a rough or rattling one is worth checking before you buy.
Related terms
Where this comes up
Pages on this site that use the term.
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- Breitling Chronomat B01 Chronograph 42, white dial, steel braceletWatch reference
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