Watch Glossary

Your comprehensive guide to watch terminology

A

Automatic Movement

A self-winding watch movement powered by a rotor that moves with wrist motion.

B

Balance Wheel

A wheel inside a mechanical watch that oscillates back and forth, regulating timekeeping.

Bezel

The outer ring around the watch crystal, which can be fixed or rotating (e.g., dive bezel, tachymeter).

C

Chronograph

A watch with a built-in stopwatch, controlled via pushers.

Complication

Any function beyond basic timekeeping (e.g., date, moonphase, GMT).

D

Dial

The face of the watch, displaying the time and complications.

Dual Time / GMT

A watch that displays two time zones at once, often using a 24-hour hand.

E

Escapement

A mechanism that regulates energy release in mechanical watches.

Exhibition Case Back

A transparent case back (often sapphire crystal) that lets you see the movement.

G

Guilloché

A decorative engraved pattern found on watch dials.

H

Helium Escape Valve

A valve that releases helium gas trapped inside the watch during deep-sea diving.

I

Indices

The hour markers on a watch dial (e.g., numerals, baton markers, Roman numerals).

J

Jewels

Synthetic rubies/sapphires used in watch movements to reduce friction.

L

Lugs

The extensions on the watch case where the strap or bracelet is attached.

Lume (Luminous Material)

A glow-in-the-dark coating applied to hands and indices for visibility in low-light conditions.

M

Manual-Wind Movement

A mechanical movement that must be wound by hand to keep running.

P

Perpetual Calendar

A self-adjusting date complication that accounts for leap years and different month lengths.

Power Reserve Indicator

A feature that displays the remaining energy stored in the watch's mainspring.

Q

Quartz Movement

A battery-powered movement regulated by a quartz crystal, known for high accuracy.

R

Rotor

A semi-circular weight inside an automatic watch that moves with wrist motion to wind the mainspring.

S

Sapphire Crystal

A highly scratch-resistant transparent cover protecting the watch dial.

Skeleton Dial

A dial that is partially or fully open to expose the inner movement.

Swiss Made

A designation indicating that a watch meets Swiss manufacturing standards (minimum 60% Swiss components).

T

Tachymeter

A scale on the bezel or dial used to measure speed over a known distance.

Tourbillon

A high-end mechanical feature that reduces the effects of gravity on the balance wheel, improving accuracy.

W

Water Resistance Rating

A measure of how well a watch withstands water exposure (e.g., 30m = splash-resistant, 200m = diving).