Aperture to Tourbillon: 23 Watch Terms to Know

Aperture to Tourbillon: 23 Watch Terms to Know

Watch terminology needn't be intimidating. In this guide our Sotheby's watch specialists summarize 23 key terms.
Watch terminology needn't be intimidating. In this guide our Sotheby's watch specialists summarize 23 key terms.

T here is no denying that watchmaking is high-art, from its complex mechanisms and complications to the painstakingly intricate designs. From Audemars Piguet to Patek Philippe to Rolex, the terms of the watch world are nearly universal and important to understanding what type of watch works best for you. Below, we will guide you through the components, complications, and movements within watchmaking to assist you in your watch collecting journey.

Our global network of watch specialists are on hand to provide their expert knowledge, whether that's selling or buying a watch. We cover everything from timeless designs such as the Cartier Tank or Rolex Submariner, through to selling some of the most complicated watches ever produced from the likes of A. Lange & Söhne, Patek Philippe and Vacheron Constantin.

Components

Aperture An aperture is a small window that displays indications such as the date, day or moon phase.

The timeless design of the Rolex Submariner has barely evolved since its introduction in 1954, such was the quality design of this robust, highly water-resistant luxury diver's wristwatch. This is the Rolex Submariner Date model , with an aperture at 3 o'clock dsiplaying the date. Sold in 2021 for £9,450 through our London Sale Room.

Bezel A watch’s bezel is the forward-facing ring surrounding the dial.

A watch defined by its bold 24-hour bezel, the Rolex GMT Batman is a variant of the GMT-Master originally designed for pilots travelling across multiple timezones.

Case Known as the body of the watch, the case contains all its inner workings and gears.

The rugged casing of the AP Royal Oak Offshore is one of its defining features, making it a very wearable watch. This example sold for HKD 302,400 in our 2022 Important Watches sale.

Crown The crown is used to set the time and, when relevant, to wind the watch’s mainspring.

The name of the Cartier Ballon Bleu ("Blue Balloon") is inspired by the unique blue sapphire cabochon crown that appears as if it’s floating on the side of the watch, encased in a protective arch. This crown design is a defining feature of many Cartier watches.

Dial Casually referred to as the face or front of the watch, the dial displays the time among other possible information.

This Audemars Piguet Royal Oak perfectly blends form and function, with the beautifully rendered dial both easily legible and aesthetically appealing.

Escapement Often referred to as the heartbeat within the watch, the escapement regulates timekeeping. While hundreds of different escapements have been modified and invented over the years, the most common modern version is the lever escapement.

Omega invested considerable sums commercializing the co-axial escapement, a complex mechanism originally designed by none other than George Daniels. This Omega DeVille utilized this form of escapement.

Hands The watch’s hands point to the correct time or other information located on the dial.

The broad-arrow hands of this Omega Speedmaster provide excellent legibility, honouring its DNA as a highly functional timepiece.

Indexes Indexes are the markings (shapes, numbers, Roman numerals, etc.) that hands point to in order to tell time.

Revered watchmarker Breguet is renowned for its carefully considered indices, showcased here with this white gold Reference 5140.

Lugs Part of the watch’s case, lugs hold onto the strap or bracelet.

The lugs of a watch form a deceptively important part of ensuring a harmonious design, exemplified with this Patek Philippe Calatrava.

Complications

Complication In simplest terms: A complication is something a watch does. Individual complications can include chronographs, calendars and more. If a watch has a combination of at least three different advanced functions, it’s referred to as a grand complication.

Introduced in 2004 the Sax-O-Mat Langematik Perpetua l was the first ever wristwatch from the brand to incorporate a perpetual calendar with an automatic movement. A showcase of A. Lange & Söhne's mastery of complications, this Sax-O-Mat Langematik including the continuously moving moon phases, the patented big date and zero-reset mechanism on the seconds, just to name a few.

Annual CalendarThe annual calendar complication shows the day, date and month without accounting for leap years.

This refined Patek Philippe Nautilus seamlessly integrates annual calendar functionality with complications like moon phases and 24 hours indication.

Chronograph A chronograph is essentially a stopwatch that has the ability to measure time or an event. Within chronographs there are different variations, including the split-seconds chronograph, which can time two things simultaneously.

The Rolex Daytona remains the most famous chronograph ever produced., with the black-and-white Panda variant instantly recognizable.

Day/DateThis complication indicates both the day of the week and the date of the month.

Introduced in 1956, the Rolex Day-Date revolutionized wristwatches by being the first model to display both the day and date separately on the dial. Featuring an extra-wide aperture at 12 o'clock, it spelled out all seven days of the week.

Moon PhaseThe moon phase complication gives you a visual representation of phases of the lunar cycle, either in a picture or in days.

The moon phase function of this Patek Philippe Sky Moon "988" is just one of twelve complications of this technological tour de force. It was the most complicated wristwatch at the time of its launch, incorporating 694 parts. Sotheby's sold this was for HKD12,475,000 in 2022.

Perpetual CalendarThe perpetual calendar complication shows the day, date and month while accounting for leap years. That’s the big difference between perpetual and annual calendars.

This extraordinary Vacheron Constantin 43032 included perpetual calendar functionality in a striking skeletonized design. Dating from 1990, we sold this watch in New York in 2022.

Power Reserve IndicatorOne popular complication is the power reserve indicator, which tells the wearer how long a watch will last or keep going before it needs to be wound.

This striking Tourbillon Souverain model from esteemed watchmaker F.P. Journe incorporated a power reserve indication.

Repeater A repeater is a watch that can chime the time. There are different variations, including minute repeaters that strike different tones for hours, quarters and minutes.

Look back at some of the distinctive complications from Patek Philippe featured in our Hong Kong sale in April 2024.

TourbillonThe tourbillon is a special type of escapement that rotates on an axis in order to counteract the effects of gravity and thus improve accuracy in a mechanical watch. A feat to be made, it’s considered a calling card of high horology.

Renowed for producing watches of extraordinary levels of technical complexity, this Richard Mille RM003 AF WG utilizes a manual winding tourbillon movement with hours, minutes, dual time zone indicator, function selector, power-reserve and torque indicators.

Movements

Movement Mechanical or quartz, the movement is what’s inside a watch and makes it run.

This extraordinary Patek Philippe 5180/1R-001 has a skeletonized dial, allowing the observer to marvel at the self-winding caliber 240 SQU movement. Available through our Buy-Now offering.

Quartz Quartz watches utilize a battery or capacitor to charge and run the watch.

For some watch owners the practicality of a quartz movement can be a real benefit, for example negating the need for re-setting the time if the watch is worn intermittently. A number of the most prestigious models are also available with quartz movements - this AP Royal Oak for example featured on our Buy-Now offering.

Mechanical |Mechanical watches run without batteries and can be divided into either the automatic/self-winding or manually wound categories.

The Lange 1 is one of the many timepieces A. Langhe & Sohne produce that is manually wound. The user regularly winds the watch using the crown, directing energy to the mainstream barrel so the watch keeps ticking.

Automatic An automatic movement is wound by the oscillating weight (known as a rotor) inside the watch that moves in unison with the wearer’s wrist.

For many watch lovers the Omega Speedmaster was their first introduction to automatic watches, offering form and function in a timeless design.

Manual Manual watches are powered by winding the crown, which connects to the mainspring.

Reference 2526 , launched in 1953, was the first self-winding wristwatch made by Patek Philippe and its production ceased in 1960.

Buying and Selling Watches at Sotheby's

Sotheby's is on hand to support your next watch purchase or sale of an existing watch. We have an extensive offering of carefully curated watches, covering everything from excellent value watches to extraordinary pieces with advanced complications.

Trust our worldwide network of leading specialists from a globally renowned auction house with a 280 year history.

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