Component record · Dial & hands
Subdial
VerifiedA smaller, secondary dial set into the main dial, displaying an auxiliary indication such as running (small) seconds, a chronograph totaliser, or a power-reserve indicator.
What it does
Provides a separate, clearly demarcated display for a function distinct from the main hour-and-minute indication.
How it works
Each subdial is driven by its own arbor, geared appropriately for its function — a small seconds subdial by the fourth wheel's seconds pinion running once per minute, a chronograph minute or hour totaliser by the chronograph module's own gearing.
Subdial layout and count is a common way to describe a complicated dial (e.g. a 'tri-compax' chronograph has three subdials).
Evolution
From simple small-seconds subdials to elaborate multi-register chronograph and complication dials as movement complexity increased through the 20th century.
Known variations
- Small (running) seconds subdial
- Chronograph 30-minute or 12-hour totaliser subdial
- Power-reserve indicator subdial
- Moon-phase subdial
Identification for collectors
- Number and placement of subdials is a quick way to identify likely complications present without opening the case
Common failure modes
- Subdial hand misalignment relative to its printed scale
- Wear or fading distinct from the main dial owing to different finishing
Photographs
Photographs are illustrative examples of the type, not necessarily the exact object described. Verify details against the source file page.
Sources & references
- Daniels, G., Watchmaking
Where sources disagree, the disagreement is stated rather than resolved silently.