All the parts of a watch, explained
Jamie WeissWatches are complex things – that’s why we like them so much. But even for seasoned collectors, it can be hard to keep on top of all the different elements of a timepiece – ask the average watch nut what the difference between a chapter ring and a rehaut is, and they probably wouldn’t be able to answer you. Well, worry no more. Whether you’re fresh to watches and need a glossary explaining all the common elements of what makes up a watch, or you’re a dyed-in-the-wool watch nerd who’s secretly always been confused by some terms, we’ve put together this helpful guide.
Bezel
In the jewellery world, a bezel refers to a rim that encompasses and fastens a jewel. The same is true for watches: a watch’s bezel is the ring around the crystal. Bezels can be fixed, but many watches (such as dive watches) feature rotating bezels, which can be used to measure elapsed time, additional time zones or compass bearings. A common type of bezel you’ll also hear about is tachymeter bezels, which are a common feature of chronographs and are used to measure average speed between two fixed points. Bezels can be made from many materials: usually, they’re made from the same material as the watch’s case. Rotating bezels often feature inserts made from ceramic, sapphire crystal, or aluminium.
Bracelet
A watch’s bracelet is the band that secures the watch to one’s wrist. We call these bands bracelets if they’re made out of metal, and if they’re made out of leather, fabric, or rubber we call them a strap. The term “integrated bracelet” refers to a band that’s directly connected to a watch’s case (rather than via a usual lug and spring bar situation), creating a seamless look – some famous watches with integrated bracelets include the Audemars Piguet Royal Oak, Patek Philippe Nautilus, Vacheron Constantin Overseas and Tissot PRX.
Case
The case is the foundation of a watch: it’s the central piece of material that houses the movement and dial. Most watch cases are round, but other shapes exist such as square cases, rectangular cases, “tonneau” or barrel-shaped cases, and so on. Enthusiasts tend to describe any watch that’s not round as having a “shaped” case. Watch cases can be made from a wide variety of materials: stainless steel is the most common case material in modern watchmaking, but other common materials include gold, platinum, ceramic, carbon fibre and plastic. A case’s diameter is the figure most commonly used to express how big a watch is.
Caseback
The caseback is the rear lid that seals a watch’s outer case. Usually, these are made out of solid metal, but sometimes they will also feature a transparent window that exposes the movement – these are called exhibition casebacks. Casebacks are usually either screwed into the case or attached via screws. In some instances, they form an integral part of a watch’s case, sandwiching the upper lugs and bezel with a central portion that contains the movement.
Chapter ring
Not to be confused with the rehaut, a chapter ring is a ring mounted on the outer edge of a watch’s dial, typically decorated with marks or indices for timing indications. Chapter rings can be on the edge of a watch’s dial or on the rehaut.
Complications
A complication is any function on a watch that goes beyond telling the time – essentially, anything that makes a watch more “complicated”. It’s a broad term – some watch enthusiasts consider even basic features like date windows as complications, while other watch elements that fall outside of the traditional definition of a complication such as tourbillons are also considered one. Common watch complications include chronographs, GMTs, minute repeaters and perpetual calendars.
Crown
A watch’s crown is the knob on the side of its case that’s used to set the time and wind the movement. Typically, you’ll find a watch’s crown at the 3 o’clock position, but some brands place crowns elsewhere: for instance, Seiko often mounts crowns at 4 o’clock, while Bovet sometimes mounts crowns at 12 o’clock, emulating the standard crown position of pocket watches. On more complicated watches, such as perpetual calendars, the crown is also used to operate other watch functions. Typically, one operates a crown by pulling it out slightly – some crowns feature multiple ‘steps’ or positions to perform different functions – however, some watches feature “screw-down” crowns that need to be unscrewed before they can be operated. Crown guards are pieces of a watch’s case that flare out and flank its crown, protecting the crown from impacts.
Crystal
The crystal is the transparent barrier that covers and protects the watch’s dial. Confusingly, we call them “crystals” even though they’re not always made from crystal: mineral glass, plexiglass (sometimes called “hesalite”) and synthetic sapphire crystal are all common crystal materials that all have their own pros and cons.
Dial
Also called a watch’s face, the dial is the portion of the watch that displays the time. (Purely digital watches aren’t usually described as having dials, rather they have displays.) Typically dials are made out of plated brass, but other materials like semi-precious stones or enamel are also commonplace in watchmaking. Watches that are “skeletonised” don’t have traditional dials: rather, they expose the movement beneath with only small armatures for indices.
Hands
A watch’s hands are the stalks that rotate around the dial to tell the time. Most analogue watches will have at least two hands: a longer hand that denotes the minutes, and a shorter one that denotes hours. A third, usually thinner seconds hand is also common. Hands also appear on watch dials to indicate other functions, such as power reserve indicators or chronograph seconds/minutes/hours/etc. Watch hands come in a variety of designs, from simple stick hands to more ornate designs incorporating bevelling or lume.
Head
A watch head is simply a watch without a bracelet or a strap; it’s the actual, substantive “watch” part of the watch.
Indices
Indices, or hour markers, are the marks that indicate the hours on an analog watch dial. Sometimes, these take the form of numerals, while other times they can be shaped like simple geometric shapes like lines or dots. Some watch dials don’t feature any indices at all. If you hear the term applied indices, that refers to physical markers that are placed on a watch’s dial, as opposed to painted-on indices, for example.
Lugs
Lugs, also known as the watch horns, are the four extensions of a wristwatch case used to attach a strap or bracelet. Traditionally, lugs were often soldered onto a watch’s case, while these days, lugs tend to be an integral part of the case. Lug width refers to the distance between the lugs, which dictates what size strap or bracelet will fit a watch. Another term you’ll encounter is lug-to-lug, which refers to the distance between the two outer ends of the watch’s lugs (which is typically larger than a watch’s case diameter and is therefore often a more accurate indication of how a watch wears). Most watches feature carvings on the inner sides of their lugs to fit spring bars, while some watches have “drilled lugs” which have holes completely drilled through from side to side, which makes it easier to remove spring bars.
Lume
Lume is shorthand for the luminous phosphorescent glowing solution applied on watch dials and other watch elements. Formerly, watch lume was made from pigments containing radioactive radium – however, radium lume has long since been phased out of the watch industry. Some watches use tritium lume, which is also radioactive but far less dangerous than radium. These days, lume on most watches is made from strontium aluminate-based compounds such as the ubiquitous Super-LumiNova or Lumibrite.
Movement
Other than the case, the movement is the most important part of a watch. Also called a calibre, it’s the mechanism that, quite literally, makes a watch tick. There are two main types of watch movements: mechanical and quartz. Mechanical movements use a clockwork mechanism driven by a mainspring, which can either be hand-wound (a “manual” watch) or wound automatically via a self-winding mechanism (an “automatic” watch). Quartz watches, on the other hand, use an electronic oscillator regulated by a quartz crystal to keep time and are powered by batteries. There are other types of watch movements that don’t fit neatly into these two definitions, such as Seiko’s Spring Drive technology.
Pushers
Pushers are external buttons on a watch case used to activate complications, most commonly, the timer of a chronograph – however, pushers are also used to cycle the date window, chime a minute repeater or advance an hour hand in a GMT watch. Some watches, such as the Rolex Daytona, feature screw-down pushers that need to be unscrewed like a crown in order to be used.
Rehaut
Also less glamorously described as a flange, the rehaut is the rim between a watch’s dial and its crystal which keeps everything situated at just the right height. Some watch’s rehauts are decorated: Rolex models famously feature the Rolex brand name engraved around the rehaut.
Rotor
Also called an oscillating weight, a rotor in an automatic watch is a balanced weight that continuously winds a watch’s mainspring via the movement of the wearer’s wrist. These are often made out of dense or heavy materials like gold or tungsten to give them more inertia.
Spring bar
Spring bars are small rods with retractable end pins used to attach a watch’s strap or bracelet to its lugs. Spring bars are by far and large the most common form of watch bar. Some watches feature screwed bars that require screwdrivers or specialised tools to remove, but these are far less common than spring bars.
Sub-dial
Sub-dials are small secondary dials within a watch’s main dial that provide additional information beyond the main handset. They’re most commonly found on chronographs, but can also denote other functions such as the date, power reserve, a second time zone or a moonphase. Many watches feature sub-dials to denote running seconds rather than a third central seconds hand; these are called “small seconds” (or “petite seconde” in French).