Watch Glossary
1676 horological terms explained · 1/2
Chronograph designed for motorsports with tachymeter scale and precise timing capabilities.
Brushing pattern radiating outward from center point like spokes
Vintage luminous materials containing radioactive elements like radium or tritium for continuous glow
Radioactive luminous material used in watch dials pre-1960s, now considered hazardous
Collector assessment of radioactive dial degradation; darker dials indicate stronger historical radiation.
Vintage dial with radioactive radium-based lume, highly collectible and dangerous.
Documentation of radioactive paint degradation patterns specific to watch manufacturing era.
Radioactive luminous paint used pre-1960s; highly collectible but hazardous.
Observable color shift in radioactive luminous material from original cream to butterscotch or brown.
Parallel metal rails securing elongated gemstones in linear watch designs.
Vintage dial style with distinct numerals used for railway timekeeping
Toothed wheel in the winding mechanism that prevents mainspring from unwinding during manual winding.
Clasp with teeth that engage incrementally for precise tension control
The measure of how many seconds per day a watch gains or loses.
Consistency of watch rate over time without external adjustment.
Software feature in timing machines that tracks chronometric performance changes over service intervals
Difference in watch rate between various positions and conditions.
Split-seconds chronograph with two independent stopwatch hands that can be separated and recombined.
Split-seconds chronograph where the second hand can be stopped independently to measure intermediate times.
Four-sided case with right angles and straight edges, elongated horizontally or vertically.
Vintage Submariner with red text dial printing, collectible early reference variant.
Collector term for watch that has been refinished with new dial printing; reduces market value significantly.
Proportion of gear teeth determining speed reduction between successive gear stages
Model designation assigned by manufacturer identifying specific watch variant and specifications
Bezel professionally repolished, reducing originality grade and collector value.
Chronograph with countdown mechanism and acoustic signal for yacht race starting procedures.
Adjusting watch movement accuracy to achieve correct timekeeping performance
Adjustment of hairspring or balance wheel to modify watch rate.
Watch with separate subdials for hours, minutes, and seconds for precise timekeeping.
Measurable side-to-side movement of the timing lever pin within its mounting point.
Design feature minimizing transmission of external vibrations to the hairspring timing mechanism.
Adjustable pointer that alters effective length of balance spring to regulate rate
Permissible gap between the regulator pin and the hairspring timing lever contact surface.
Circular engraved area between dial edge and case inner bezel.
Typeface examination of case inner ring text to identify period-specific variations.
Luminous coating sometimes applied to the watch rehaut ring near the dial edge
Professional restoration service applying new luminous material to vintage watch dials and hands
Intermediate wheel system providing constant force and regulating energy from the mainspring.
Complicated watch striking hours, quarters, or minutes audibly when activated by pusher.
Non-original dial installed during service; significantly reduces watch value.
Non-original components installed during service or repair, noted by collectors for authenticity
Auction house outcome where final hammer price falls below minimum reserve, influencing future valuations.
Dynamic e-ink dial elements that update synchronously with hybrid watch mechanics
Two balance wheels oscillating together to improve stability and accuracy through mutual synchronization.
Paired balance wheels vibrating in resonance to improve chronometric stability and precision.
Complication with hand sweeping across arc then jumping back to start, indicating time passage.
Hand jumps back to start position instead of rotating continuously, creating dramatic visual effect.
Technique where metal beneath gemstone curves upward supporting stone edges.
Watch dial with black background and white subdials, opposite of traditional panda.
Vintage chronograph dial variant with dark subdials against light main dial, opposite of standard panda design.
Jaeger-LeCoultre's art deco rectangular flipping case watch from 1931
Applying thin rhodium coating for bright, reflective finish and improved corrosion resistance.
Case design sealing crystal, case, and back for exceptional water resistance.
Metal pin permanently securing links together in a bracelet.
Perpetual rotor, Parachrom hairspring, 48-hour power reserve, widely used in sports watches
Evolved 3135 with Chronergy escapement, 70-hour power reserve, improved efficiency
GMT-Master II exclusive, dual time module, 70-hour reserve, Chronergy escapement
Rolex's proprietary bracelet extension system allowing micro-adjustments without removing links, debuted in 2005.
Proprietary automatic winding system in Caliber 3135, featuring bidirectional winding and optimized energy transfer.
Proprietary triple-sealed crown mechanism in Caliber 3135 watches, ensuring exceptional water resistance integrity.