Component record · Keyless work
Crown
VerifiedThe external knurled knob, typically at the 3 o'clock edge of the case, used to wind the mainspring and set the time (and, on many watches, the date).
What it does
Provides the user's manual interface to the keyless works: turning winds or sets, and on many models pulling to defined positions selects the function.
How it works
Turning the crown rotates the stem, which — depending on its pushed or pulled position — drives either the winding train (to the ratchet wheel and mainspring) or the setting train (to the motion works and hands) via the keyless works.
Screw-down crowns, common on water-resistant watches, additionally thread onto a case tube to compress a gasket and seal the pendant when not in use, and must be unscrewed before winding or setting.
Evolution
From plain winding-only crowns to multi-position crowns (wind, date-set, time-set) on complicated watches, and to gasketed, screw-down crowns for water resistance from the mid-20th century onward.
Known variations
- Plain push-pull crown
- Screw-down (water-resistant) crown
- Multi-function crown with several defined pull positions for date and time setting
Identification for collectors
- Screw-down crowns show a knurled locking collar and require unscrewing before use
- Wear or looseness at the crown often indicates a worn stem or case tube thread
Common failure modes
- Stripped screw-down threads compromising water resistance
- Worn knurling reducing grip
- Detachment from the stem
Photographs
Photographs are illustrative examples of the type, not necessarily the exact object described. Verify details against the source file page.
Sources & references
- de Carle, D., Practical Watch Repairing
Where sources disagree, the disagreement is stated rather than resolved silently.