WatchesAtlas / Watch knowledge
The Watch Encyclopedia
Understand the details that make a watch.
562 terms
Authorised dealer
A retailer formally appointed by a brand to sell its products.
Movements & mechanismsAutomatic winding
A mechanism that winds the mainspring using the wearer's movement, usually through a rotating weight called a rotor.
Complications & displaysAutomaton
A mechanically animated figure or scene, sometimes coordinated with a watch's striking or time display.
Cases, dials & braceletsAventurine dial
A dial using a material with sparkling inclusions, commonly aventurine glass.
Complications & displaysAzimuth
A directional angle expressed relative to a reference direction, sometimes displayed by instrument watches.
Movements & mechanismsBacklash
Clearance between meshing gear teeth that allows some free movement before torque is transmitted.
Finishing & craftsmanshipBaguette cut
A gemstone cut with a long, substantially rectangular form and step-like facets.
Movements & mechanismsBalance inertia
The rotational inertia of a balance wheel, contributing to its behaviour as part of the regulating oscillator.
Movements & mechanismsBalance rim
The outer portion of a balance wheel, where much of its regulating inertia is concentrated.
Movements & mechanismsBalance staff
The central shaft supporting the balance wheel and its related components.
Movements & mechanismsBalance wheel
The oscillating wheel that works with the hairspring to regulate a mechanical movement.
Performance & measurementBar
A unit of pressure used in watch water-resistance specifications.
Complications & displaysBarometer
A function measuring atmospheric pressure, sometimes used to indicate changes in weather conditions.
Movements & mechanismsBarrel
The drum containing the mainspring. Its toothed rim transfers stored energy into the wheel train.
Movements & mechanismsBarrel arbor
The shaft around which the mainspring is wound inside its barrel.
Movements & mechanismsBarrel cover
The closure retaining the mainspring inside a barrel while allowing its intended movement.
Cases, dials & braceletsBaton hands
Hands with a narrow, generally straight-sided outline.
Finishing & craftsmanshipBead blasting
A surface treatment using projected beads to create a controlled matte or textured finish.
Cases, dials & braceletsBeads-of-rice bracelet
A bracelet design with small rounded centre links resembling grains of rice.
Performance & measurementBeat error
A measure of asymmetry between alternating beats of a mechanical movement, commonly assessed with a timing instrument.
Cases, dials & braceletsBezel
The ring surrounding the crystal, which may be fixed or rotating and may carry a functional scale.
Cases, dials & braceletsBicompax layout
A common modern description for a chronograph dial with two principal counters.
Collecting, condition & careBid increment
The permitted or required increase between successive bids under an auction's rules.
Cases, dials & braceletsBidirectional bezel
A bezel that can rotate in either direction, used for functions such as time-zone or countdown tracking.
Movements & mechanismsBidirectional winding
An automatic winding system able to wind the mainspring as its rotor turns in either direction.
Complications & displaysBig date
An enlarged date display, often using separate components for the tens and units digits.
Finishing & craftsmanshipBlack polish
An extremely flat polished surface that can appear dark or bright depending on the viewing angle.
Cases, dials & braceletsBlued steel hands
Steel hands coloured blue through a controlled process, traditionally heat treatment.
Modern watch technologyBluetooth connectivity
A short-range wireless connection used by some watches to exchange data or synchronise with a compatible device.
Cases, dials & braceletsBox crystal
A raised crystal with a profile resembling the stepped or vertical-sided shape of traditional acrylic crystals.