Watch Glossary
1356 horological terms explained · 1/2
Number of seconds per day a watch runs ahead of correct time.
Electrochemical process depositing thin metal layers onto watch dials for color and finish enhancement.
GTLS technology using tritium gas in sealed tubes to provide continuous watch dial illumination
Rubber or synthetic seal that creates water-resistant barriers around openings.
Replacement of rubber or synthetic seals that prevent water and dust ingress
Unit of measurement for magnetic field strength affecting watches.
Series of interconnected gears that transmit and regulate energy throughout the movement.
Temperature-controlled process bonding adhesive used in invisible settings.
Testing protocol evaluating stone adhesion and mechanical durability in watch environment.
Hallmark certifying excellence in watchmaking, awarded by Geneva Canton
Parallel lines pattern applied to movement plates, also known as Cotes de Geneve or Genevese stripes.
Software processing arm movements to trigger watch functions without screen interaction
Accelerometer-based software interpreting wrist flicks and rotations as command inputs
Faded or nearly invisible bezel markings on vintage sports watches, especially divers
Faint residual image or mark visible on dial from removed dial elements or stickers.
Thin layer of gold plating applied to brass or other base metals
Collector grading system measuring the extent of gold plating wear on applied indices and markers.
Dial with gold-plated finish giving warm vintage appearance
Hands with gold plating over brass; prone to wear revealing base metal.
Thin gold plating layer applied to brass watch components; characteristic of mid-century movements.
Ornate arrangement with central gemstone flanked by pear-shaped stones.
Sliding adjustment mechanism on dive extension for precise custom fit
Rolex clasp system allowing micro-adjustment with sliding mechanism for easy sizing
Rolex's tool-free micro-adjustment bracelet system for dive suit wear
Shiny dial finish, less common on vintage sports watches, more typical of dress models
Time period during which watch lume remains visibly luminous after light exposure stops
Complication displaying two time zones simultaneously, typically with a 24-hour hand for second time zone.
Specialized bezel with 24-hour markings for tracking multiple time zones.
Second time zone display allowing simultaneous viewing of time in two different locations.
Rolex dual time zone watch with independent 24-hour hand, developed for airline pilots.
Specialized movement with independent hour hand for tracking second time zone simultaneously.
24-hour scale on dial or bezel for tracking second time zone
Dual time zone watch with 24-hour hand showing a second timezone simultaneously.
Rolex's dual time zone pilot watch featuring 24-hour hand since 1955
Additional timezone display showing simultaneous time in different locations worldwide.
GPS/GLONASS/Galileo/BeiDou constellation positioning engine for ultra-accurate location tracking
Precious metal used in watch cases; yellow, white, and rose gold are common varieties
Precious metal bracelet, available in yellow, white, or rose gold variants
Electroplating process coating watch parts with thin layers of gold for luxury appearance.
Highly desired timepiece representing the ultimate goal in a collector's pursuit
Gemstone held by tiny metal grains raised from base metal surface.
Textured surface with visible grain pattern creating visual interest
High-temperature enamel firing process creating durable, lustrous colored watch dial surfaces.
Watch combining multiple complex functions like perpetual calendar and minute repeater
Most complex striking complication that chimes hours and quarter-hours automatically throughout the day.
Visual representation on timing machines showing real-time deviation from chronometer standard accuracy.
Harrison's innovative escapement mechanism using three pivoted pallets for efficient energy transfer
Traditional luminous material that glows bright green in darkness, common in vintage and modern watches
German military certification for precision timekeeping from Gesellschaft für Strahlenforschung.
German military requirements for dial layout, lume placement, and readability standards.
German military requirement for co-axial or chronometer escapement in precision military timepieces.
German precision watchmaking standard for military chronometers requiring ±15 seconds monthly rate.
German military precision testing protocol for movement accuracy and reliability validation.
German military chronometer certificate documenting daily rate, amplitude, and beat error measurements.
German military (Bundeswehr) timekeeping and precision standards for issued timepieces.
Abbreviation for gaseous tritium light source, a self-illuminating watch dial technology
Decorative hand-engraved pattern applied to watch dials creating intricate geometric surface designs.
Precision lathe attachment for engraving repeating geometric patterns on dial surfaces.
Decorative machine-engraved pattern with repetitive geometric or wavy lines.
Decorative machine-engraved pattern on watch dials and components