Watch Glossary

Three-piece link design with center H-shaped connectors, offering flexibility and comfort

John Harrison's first marine chronometer, completed in 1735 using a grasshopper escapement

Harrison's pocket watch-style chronometer that won the Longitude Prize with remarkable accuracy

Second hand stops when crown pulled, enables precise synchronization, common in field watches

Fine surface scratches on dial or case; minor cosmetic flaw in grading scales.

Fine surface scratches on polished watch case surfaces, expected on worn vintage timepieces

Delicate spiral spring attached to the balance wheel that controls its oscillation rate.

Careful removal and cleaning of delicate hairspring without deformation

Condition where hairspring loses elasticity, causing poor timekeeping especially during acceleration.

Fixed point anchoring one end of hairspring to balance cock or balance wheel

Pocket watch case with small opening in cover allowing dial to be viewed without opening fully.

Official Swiss quality certification for watches made in Geneva region

Central gemstone surrounded by smaller diamonds in concentric ring arrangement.

Undisclosed minimum bid amount required to win auction lot.

Irregular dimpled surface mimicking hand-hammering technique

Manually cutting decorative designs into watch components using specialized engraving tools.

Luminous material applied to watch hands enabling visibility in darkness

Age-related discoloration of watch hands; varies from subtle to dramatic.

Mechanical press tool for installing watch hands with precise alignment and pressure

Edges manually angled and finished by hand for sophisticated look

Manually beveled edges at precise angles for refined appearance

Surface finished by hand using polishing compounds for refined shine

Manual winding required, no automatic rotor, lighter and simpler design, 4R36, 6R35, 240

Installation of new watch hands when original is damaged or worn

Complete assembly of hour, minute, and seconds hands in coordinated design.

Enlarged, contrasting hour hands critical for quick time reading during dives.

Watch collecting emphasizing physical evaluation and appreciation of timepieces over investment

Vintage watches where date changes coincide with hour hand position at midnight.

Miniature vibration motor providing tactile notifications without audible alerts

Miniature linear actuator providing directional vibration patterns for notifications and alerts

High-Accuracy Quartz movement achieving annual rates better than ±10 seconds.

High watchmaking; artisanal craftsmanship producing exceptional mechanical timepieces

Heating metal to specific temperatures to alter hardness, strength, and other physical properties.

One-way valve on the case allowing pressurized gas release during decompression.

Condition where helium gas saturates diver tissues during extended deep work.

Gas escape valve used in dive watches to release helium trapped during saturation diving decompression

Acrylic plastic crystal material used in vintage watches; lightweight and prone to scratching

Abbreviation for helium escape valve; critical for deep saturation diving operations.

Mirror-like reflective surface achieved through progressive polishing

Movement with vibration frequency above 28,800 bph for smoother second hand motion.

Vertical measurement of raised hemispherical bumps in hobnail pattern, typically 0.2-0.4mm.

Specification for spacing and frequency of hobnail bumps per square millimeter on dial.

Proportional relationship between hobnail dome height and base diameter.

The calculated spherical radius of individual hobnail dome protrusions on dial.

The number of reflective facets per hobnail dome element on dial.

Quantitative measurement of how hobnail facets disperse incident light.

Evaluation of bilateral symmetry in hobnail dome formation across dial.

Raised hemispherical bumps arranged in grid pattern, resembling boot sole studs on dial.

Vintage diving watch case design featuring holes drilled in case back for rapid decompression.

Case made with hollow sections inside the caseband to reduce weight while maintaining durability.

Lightweight bracelet link with interior space, reducing overall weight.

Bracelet links with interior space, lighter weight and cost-effective construction

Timepiece inspired by or closely resembling another iconic watch design

Dial surface with hexagonal pattern texture resembling honeycomb structure

Fine abrasive machining process achieving smooth surfaces and precise hole diameters.

Parallel horizontal lines creating soft, satin-like surface texture

Relating to the science, study, and art of timekeeping and watch design

Master craftsperson specializing in the design, construction, and repair of clocks and watches

Premium shell leather from Horween tannery, develops deep patina, extremely durable

Indices positioned at hour positions indicating time divisions on dial.