Watch Glossary

Omega Speedmaster Professional, official NASA moon landing chronograph from Apollo missions.

Reference number assigned to military watch procurement contracts in NATO inventory system.

13-digit North Atlantic Treaty Organization catalog identifier for military watches.

Engraved NATO identification number on military watch case or bracelet connector bar.

International cataloging system assigning unique identification codes to military watches.

NATO Stock Number military catalog reference enabling supply chain tracking.

Group of military watches manufactured under single NATO stock number specification.

Additional outer coil on hairspring that improves isochronism and temperature stability

Components of escapement that engage and release the escapement wheel in precise intervals

Historical hallmark symbol punched on PP movements and cases, representing brand heritage since 1932.

Iconic Rolex Daytona worn by actor Paul Newman, named after the exotic dial variant he preferred.

GMT-Master II with red and blue bezel insert, nicknamed for Pepsi-like color scheme.

Small rounded points on watch components that allow smooth rotation in jeweled bearings

Portable timepiece carried in pocket, popular from 17th century until wristwatch era.

Timekeeping variation depending on the position or orientation of the watch mechanism

Documented ownership history from manufacture through current owner.

Vintage dial with radioactive radium-based lume, highly collectible and dangerous.

Vintage Submariner with red text dial printing, collectible early reference variant.

Adjustable pointer that alters effective length of balance spring to regulate rate

Auction house outcome where final hammer price falls below minimum reserve, influencing future valuations.

GMT-Master II with brown and black bezel insert, resembling root beer coloring.

Long-term changes in watch accuracy caused by wear, aging, and environmental factors

Documentation establishing authenticity and sourcing of historically replaced dials.

Auction term for letters, receipts, and service records proving professional maintenance chain.

Collector slang for recently released limited edition purchased primarily for resale appreciation.

Specialized steel alloy used in hairsprings and mainsprings for its elasticity and durability

Elegant S-shaped bracket used to adjust the hairspring length for fine timekeeping adjustments

Mechanism to counteract effects of temperature changes on timekeeping accuracy

Rare watch manufactured during factory production change, serving as authentication standard for collectors.

Dial design between major production eras, combining features of both generations.

Early escapement mechanism using a rotating verge to regulate energy release from mainspring

Early Submariner with disproportionately wide case, reference 5508 and 5510.