Watchmaking possesses a rich vocabulary that can sometimes be challenging to master.
Caliber, movement, mechanical, automatic... this watchmaking glossary gathers the main terms used to describe a watch, its components, its functions, and its finishes.
A
| Accuracy | Daily variation between a watch's running rate and a time reference, typically measured in seconds per day for mechanical watches. |
| Acrylic crystal | Lightweight, impact-resistant synthetic plastic that does not shatter. On the other hand, it is very sensitive to scratches, although it is easy to repolish. Located around 2-3/10 on the Mohs scale. |
| Anti-reflective coating (crystal) | Chemical treatment generally applied to the inner surface of the glass (often sapphire) in order to reduce light reflections and optimize the readability of the dial.It can display a discreet shade, providing a slight color reflection depending on the angle of exposure to light. |
| Applied index | Hour-marking element (numeral, stick or symbol) manufactured separately and then fixed in relief on the surface of the dial by riveting or gluing. Unlike a painted or printed index, the applied index adds volume, light effects and a high-end finish to the dial. Solution adopted by riveting on the Waypoint collection of DÉDALE watches. |
| Automatic | Refers to a mechanical watch whose mainspring is wound by wrist movements via an oscillating weight (or rotor). Synonyme of Self-winding. |
B
| Balance wheel | Oscillating component of a mechanical movement that regulates its timekeeping rate. |
| Barrel | Component containing the mainspring that stores the energy required to run the watch. |
| Bezel | Ring surrounding the crystal and dial. It can be fixed or rotating and feature various scale markings. To go further: Scales and Bezels: The Complete Flight Tools Guide |
| Bezel insert | Inlaid component fitted onto a bezel, typically carrying graduations or markings. |
C
| Caliber | Designation of a specific watch movement, generally identified by a reference number. The term can refer to the particular architecture and configuration of a mechanical or quartz movement. |
| Cam | Control element of a chronograph used to coordinate its functions. Simpler to manufacture than a column wheel, the cam system prioritizes a practical and efficient design. |
| Case | Structure protecting the movement, comprising the case middle, bezel, and case back. |
| Case back | Rear section of the watch case that seals the watch. Possibly screwed, by screws or clipped. |
| Case middle | Central section of the watch case housing the movement. |
| Chronograph | Complication enabling the measurement of elapsed time independently of the main time display. Derived from Greek, meaning literally "to write time". To go further: Chronograph: the story of time that is no longer written |
| Chronometer | Watchmaking certification designating a watch whose accuracy has been certified according to ISO 3159. Not to be confused with the chronograph. To go further: Chronograph: the story of time that is no longer written |
| Chronoscope | Function allowing elapsed time measurement independently of the time display (an etymologically precise term compared to chronograph). DÉDALE uses it to designate its Waypoint collection. To go further: Chronograph: the story of time that is no longer written |
| Clutch | Mechanism connecting or disconnecting a complication, particularly a chronograph, from the watch's gear train. |
| Column wheel | Control element of a chronograph used to coordinate its various functions. Considered more prestigious than a cam mechanism. To go further: NE86 caliber technique |
| Complication | Watchmaking function extending beyond the standard display of hours, minutes, and seconds (e.g., date, chronoscope, moon phase, etc.). |
| Crown | Control that notably enables the movement to be wound and the watch indications to be adjusted. When it is screwed on, it locks against the case to reinforce the watertightness of the watch. |
| Crystal | Transparent element protecting the dial. May be made of acrylic, mineral glass, or sapphire. |
D
| Date window / Aperture | Opening in the dial through which an indication, such as the date, is displayed. |
| Dial | Plate serving as the face of the watch, carrying the markers, numerals, and sub-dials. Typically made of brass, it can also be crafted from exceptional materials like the meteorite dial of the Waypoint WP-01 Sidus of DÉDALE. |
| Double domed | Refers to a crystal where both inner and outer surfaces feature a curvature engineered for aesthetic and optical clarity. |
E
| Escapement | Mechanism controlling the release of energy from the movement and maintaining the oscillation of the balance wheel. |
F
| Flyback | Function allowing a chronograph to be reset to zero and restarted instantaneously with a single action. |
| Frequency | Number of oscillations produced by the regulating organ (balance wheel or quartz) per second, measured in Hertz (Hz) or vibrations per hour (vph). A higher frequency improves timekeeping accuracy and movement stability. To go further: NE86 caliber technique |
H
| Hacking seconds | Mechanical feature that halts the balance wheel and seconds hand when the crown is pulled out, allowing the watch to be synchronized to the exact second. |
| Hairspring | Fine coiled spring attached to the balance wheel that regulates movement timing. |
| Hand | Moving indicator on the dial showing hours, minutes, seconds, or other functions. |
| Hour marker / Index | Marking on the dial used to read the time. |
J
| Jewel | Synthetic rubies placed at strategic friction points of a mechanical movement. Used to guide the pivots of the gears, rubies reduce wear on components and minimize energy losses due to friction, thus ensuring the longevity of the calibre. The ruby is red/pink sapphire (corundum family). |
L
| Lugs | Extensions of the case middle (usually four) designed to attach and secure the strap to the watch. |
| Lug-to-lug | Total distance measured in millimeters from the tip of the top lug to the tip of the bottom lug, determining how the watch fits on the wrist. |
| Luminescence (or lume) | Property of a material allowing it to emit visible glow in the dark after light exposure. |
M
| Magnetic resistance | A timepiece's ability to maintain accuracy when exposed to ambient magnetic fields, achieved via non-magnetic components (e.g., silicon hairspring) or an inner soft-iron shield. Complies with at least the ISO 764 standard. To go further: NE86 caliber technique |
| Mechanical movement | Movement powered by energy stored in a mainspring, wound either manually and/or automatically. |
| Mineral crystal | Made of silica, often tempered thermally or chemically to improve strength. It offers a good compromise: it is much more scratch-resistant than acrylic, but remains more sensitive to scratches than sapphire. Located at 5-6/10 on the Mohs scale. |
| Movement | The complete internal mechanism powering the watch. |
O
| Oscillating weight | Semi-circular rotor mounted on bearings that transforms wrist movements into winding energy for a mechanical movement, enabling automatic winding. Synonym: rotor. |
P
| Power reserve | Duration a mechanical watch continues running after being fully wound. |
| Push-piece / Pusher | Button used to operate a specific mechanism, notably a chronograph. |
Q
| Quartz | Mechanism powered by a battery stimulating a quartz crystal at high frequency. While it offers unbeatable accuracy and minimal maintenance, it remains perceived as less prestigious than a traditional gear-driven mechanical caliber. |
S
| Sandwich dial | Dial construction made of two layered plates: the top plate features cut-outs for the hour markers and sub-dials, revealing the lower plate's finishes to add depth and structure the dial layout. Dial architecture adopted in the DÉDALE's Waypoint collection. |
| Sapphire | Synthetic material (corundum family) highly resistant to scratches, used to protect the dial. It is also used for the bezel insert in DÉDALE's Waypoint collection. Rated 9/10 on the Mohs hardness scale. |
| Sapphire crystal | Crystal made of synthetic sapphire, exceptionally scratch-resistant, rated 9/10 on the Mohs hardness scale. |
| Self-winding | Refers to a mechanical watch whose mainspring is wound by wrist movements via an oscillating weight (or rotor). Synonym of Automatic. |
| Shock protection | System designed to protect the regulating organ, particularly the balance staff pivots, from damage caused by shocks and sudden accelerations. It allows the balance to retain its freedom of movement while reducing the risk of deformation or breakage of its pivots. To go further: NE86 caliber technique |
| Small seconds | Seconds display shown on a dedicated sub-dial separate from the central hands. |
| Split-seconds (Rattrapante) | Chronograph featuring two superimposed central seconds hands to measure intermediate times. |
| Spring bars | Telescopic metal pins with an internal spring, inserted between the case lugs to hold the strap in place. |
| Stainless steel - 316L | Highly corrosion, saltwater, and sweat-resistant alloy thanks to molybdenum and low carbon content. Watchmaking benchmark material, durable and hypoallergenic. |
| Sub-dials | Secondary dials integrated into the main dial to display indications separate from the central time (small seconds, chronograph counters, power reserve, date, etc.). |
| Super-LumiNova® | Photoluminescent material applied to hands and markers to optimize darkness legibility. Registered Swiss trademark. |
T
| Tachymeter | Graduated scale used to calculate average speed based on elapsed time over a known distance. To go further: Scales and Bezels: The Complete Flight Tools Guide |
| Telemeter | Graduated scale used to estimate distance based on time elapsed between seeing an event and hearing its sound. To go further: Scales and Bezels: The Complete Flight Tools Guide |
| Tourbillon | Mechanism designed to offset positional errors caused by gravity on a mechanical movement's rate. |
V
| Vertical clutch | Advanced clutch mechanism where chronograph components engage vertically, minimizing mechanical wear. To go further: NE86 caliber technique |
V
| Water-resistance | Ability of the watch to prevent any infiltration of water, dust or moisture. It is usually expressed in bars (bar) or meters (m, where 1 bar ≈ 10 m), measuring the theoretical tolerated pressure. |