Watch Dictionary
Welcome to the Watch Dictionary on WatchWired.com! This comprehensive reference guide is meticulously crafted for watch enthusiasts and horologists alike, offering an invaluable repository of terms, definitions, and concepts central to the world of horology. Whether you are a seasoned collector, an amateur horologist, or a curious newcomer wishing to delve deeper into the intricacies of timepieces, this dictionary aims to elucidate the complex jargon, mechanisms, and techniques of watchmaking. Embark on a journey of discovery through the intricate mechanics of timekeeping, and immerse yourself in the rich heritage and refined artistry that define the fascinating world of watches.
A
Acrylic crystal is a type of watch crystal that is made from a plastic material. It is commonly used in less expensive watches as a more affordable alternative to sapphire or mineral crystal. Acrylic crystal is lightweight, shatter-resistant, and can be easily polished to remove scratches. However, it is more prone to scratching and can become cloudy over time.
Alarm function is a feature on a watch that allows the wearer to set an audible alarm to remind them of a specific time or event. The alarm can be set to go off once or repeatedly at a set interval, depending on the watch’s capabilities. Some watches also have a snooze function that allows the wearer to delay the alarm for a few minutes before it goes off again. The alarm function is commonly found in digital watches but can also be found in analog watches with a separate alarm hand or a subdial dedicated to the alarm function. It is a useful feature for people who need to be reminded of important events or tasks throughout the day.
Altimeter is a feature found in some watches that measures altitude or elevation above sea level. It uses a barometric sensor to detect changes in air pressure and converts them into altitude readings. This feature is particularly useful for hikers, mountaineers, and pilots who need to accurately determine their altitude to navigate and make decisions. Altimeters can also be used to track changes in altitude over time, which can provide valuable data for activities such as skydiving or paragliding.
Analog display refers to the traditional way of displaying time on a watch with hands that move around a dial. The hour hand indicates the hour and the minute hand indicates the minutes. Some analog watches also have a second hand that moves continuously around the dial. Analog display is often preferred by watch enthusiasts for its classic and elegant look.
An annual calendar is a type of watch complication that displays the day, date, and month, and only needs to be adjusted once a year, at the end of February. Unlike a perpetual calendar, which can account for leap years, an annual calendar requires manual adjustment for the extra day in February every four years. Annual calendars are considered a mid-range complication, offering more functionality than a simple date display but not as complex as a perpetual calendar.
Anti-magnetic refers to a watch that is designed to resist the effects of magnetic fields. Magnetic fields can cause a watch to run inaccurately or stop altogether, making anti-magnetic watches an important tool for professionals who work in environments with high magnetic fields, such as pilots, engineers, and scientists. Anti-magnetic watches are typically made with special materials or technologies that shield the watch’s movement from magnetic fields. Some common anti-magnetic materials include soft iron, mu-metal, and silicon. The level of anti-magnetic protection varies between watches, with some models able to withstand magnetic fields up to several thousand gauss.
An anti-shock system is a mechanism designed to protect the delicate internal components of a watch from damage caused by sudden impacts or shocks. This system typically consists of a series of springs and/or shock-absorbing materials that help to cushion and absorb the force of any impact. This is particularly important for watches that may be subject to frequent jolts or vibrations, such as those worn during sports or other physical activities. Without an anti-shock system, a watch’s delicate balance wheel, hairspring, and other components could easily become damaged or disrupted, leading to inaccurate timekeeping or even complete failure of the watch.
Aperture is a small opening or window on a watch dial that displays additional information such as the date, day, month, or moon phase. It is usually located at the top or bottom of the dial and can be circular or rectangular in shape. The aperture is often accompanied by a rotating disc or hand that displays the information through the opening. The size and placement of the aperture can vary depending on the design of the watch, and it can add both functionality and aesthetic appeal to the timepiece.
Atmos clock is a type of mechanical clock that does not require winding or batteries. It is powered by small changes in temperature and atmospheric pressure, which cause a capsule containing a mixture of gases to expand and contract, driving the clock’s mechanism. The Atmos clock was invented by Jean-Léon Reutter in 1928 and is known for its accuracy and longevity. It is often considered a work of art due to its intricate design and craftsmanship. The clock is produced by the Swiss luxury watchmaker Jaeger-LeCoultre and is highly sought after by collectors.
Atomic timekeeping refers to the use of atomic clocks to measure time with extreme accuracy. Atomic clocks use the oscillation of atoms to keep time, which is more precise than traditional timekeeping methods. Watches that use atomic timekeeping technology are able to automatically synchronize with atomic clocks around the world, ensuring that the time displayed on the watch is always accurate to the second. This technology is commonly found in radio-controlled watches, which receive signals from atomic clocks via radio waves. Atomic timekeeping is particularly useful for people who need to keep precise time, such as scientists, pilots, and astronauts.
Automatic movement refers to a type of mechanical watch movement that is self-winding. It works by utilizing the natural motion of the wearer’s wrist to wind the watch’s mainspring, which powers the watch’s movement. As the wearer moves their wrist, a rotor inside the watch rotates and winds the mainspring. This allows the watch to keep accurate time without the need for manual winding or a battery. Automatic movements are highly prized among watch enthusiasts for their precision and convenience.
B
The balance spring, also known as the hairspring, is a tiny, coiled spring that is a crucial component in the movement of a mechanical watch. It is typically made of a special alloy that is resistant to temperature changes and magnetic fields. The balance spring is responsible for regulating the oscillations of the balance wheel, which is the part of the watch that keeps time. As the balance wheel swings back and forth, the balance spring helps to control its speed and ensure that the watch keeps accurate time. The balance spring is a delicate component that requires precise adjustment and careful handling, and it is one of the key factors that determines the accuracy of a mechanical watch.
The balance wheel is a crucial component of a mechanical watch movement that oscillates back and forth at a specific frequency to regulate the timekeeping accuracy of the watch. It is a small, circular wheel with weighted arms that are designed to counteract the effects of gravity, temperature changes, and other external factors that can affect the watch’s accuracy. The balance wheel is typically driven by a hairspring and is often visible through the watch’s caseback. Adjusting the balance wheel’s frequency is a delicate process that requires skilled watchmakers to ensure the watch’s accuracy.
A barometer is a feature found in certain high-end watches that measures changes in air pressure. This information can be used to predict changes in weather patterns, making it a useful tool for outdoor enthusiasts and hikers. The barometer function typically displays the current air pressure, as well as a trend indicator that shows whether the pressure is rising or falling. Some watches also include a storm alarm that alerts the wearer when a sudden drop in pressure indicates an approaching storm.
The barrel is a cylindrical metal container that houses the mainspring of a mechanical watch. It is an essential component of the watch movement as it stores the energy that powers the watch. The mainspring is wound up by the movement of the watch wearer’s wrist, and the energy is transferred to the barrel. The barrel then slowly releases the energy to power the watch’s movement. The size of the barrel and the length and strength of the mainspring determine the watch’s power reserve, or how long the watch can run without being wound. A larger barrel and stronger mainspring can provide a longer power reserve. The barrel is typically visible through the watch’s caseback and is often decorated with intricate engravings or designs.
The bezel is the ring that surrounds the watch face and is usually fixed to the case. It can be made of various materials such as steel, gold, ceramic, or even diamonds. The bezel can have different functions, such as marking elapsed time, calculating speed, or indicating a second time zone. It can also be unidirectional or bidirectional, depending on the purpose of the watch. Some bezels are decorated with engravings or patterns, while others are plain and functional. The bezel is an important part of the watch’s design and functionality, and it can greatly affect the overall look and feel of the timepiece.
Bidirectional winding refers to a type of automatic watch movement where the rotor can rotate in both directions, allowing the watch to be wound by the movement of the wearer’s wrist in either direction. This feature is particularly useful for people who are active or who frequently change positions throughout the day, as it ensures that the watch remains wound and accurate regardless of the wearer’s movements. Bidirectional winding is a common feature in many modern automatic watches and is often preferred over unidirectional winding, which only allows the rotor to rotate in one direction.
A bracelet is a type of watch strap that is made up of metal links that are connected together to form a band. Bracelets are typically made of stainless steel, gold, or silver, and can be polished or brushed for a variety of finishes. They are often considered more durable and long-lasting than other types of watch straps, and are popular for their classic and timeless style. Bracelets can be adjusted in size by removing or adding links, and can be secured to the wrist with a clasp or folding buckle.
A bridge is a component of a watch movement that holds the gears and other mechanisms in place. It is a flat, plate-like structure that spans the width of the movement, and is usually made of metal. The bridge is attached to the mainplate of the movement and provides stability and support for the various components. The bridge also serves to protect the delicate gears and other parts from dust and other contaminants. Bridges can be decorated with various finishes and patterns to enhance the aesthetic appeal of the movement.
A buckle is a device used to fasten the strap or bracelet of a watch around the wrist. It typically consists of a metal frame with a tongue or prong that fits through a hole in the strap or bracelet, and a pin or bar that secures the tongue in place. Buckles can be made of various materials, including stainless steel, gold, and titanium, and can be designed in different styles and shapes to complement the watch’s overall aesthetic. Some buckles also feature a deployant clasp, which allows for a more secure and comfortable fit.
C
Cabochon is a term used to describe a style of watch crown or decorative gemstone that has been polished and shaped into a smooth, rounded shape without any facets. The term comes from the French word “caboche,” which means “head.” Cabochon crowns are often seen on luxury watches and are typically made from precious materials such as gold or platinum. Cabochon gemstones are also used as decorative elements on watch dials or bezels, and can be made from a variety of materials such as sapphire, ruby, or emerald. The smooth, rounded shape of a cabochon gives it a unique and elegant appearance, and is often associated with high-end luxury watches.
Caliber refers to the specific movement or mechanism inside a watch that powers its timekeeping functions. It is essentially the “engine” of the watch and can vary in size, shape, and complexity depending on the brand and model. The caliber typically includes the balance wheel, escapement, mainspring, and other components that work together to keep accurate time. Watchmakers often use the caliber number to identify and differentiate their various watch models.
Caliper is a measuring tool used to measure the diameter of a watch case or the thickness of a watch crystal. It is typically a handheld device with two arms that can be adjusted to fit around the object being measured. The arms are then locked in place and the measurement can be read from a scale on the caliper. Calipers are commonly used by watchmakers and enthusiasts to ensure the proper fit of replacement parts and to determine the authenticity of vintage watches.
Carillon refers to a type of striking mechanism found in mechanical watches that produces a series of chimes or bells. The term is derived from the French word “carillon,” which means a set of bells played by a keyboard. In a watch, the carillon mechanism consists of three or more hammers that strike a set of gongs at precise intervals to create a melodic sequence of sounds. The complexity of the carillon mechanism can vary, with some watches featuring multiple melodies and others having a single, repeating chime. Carillon watches are highly sought after by collectors and are considered some of the most technically advanced timepieces in the world.
The case of a watch refers to the outer covering that encloses the movement, dial, and hands. It is usually made of metal, such as stainless steel or gold, but can also be made of other materials such as ceramic or titanium. The case protects the inner workings of the watch from damage and also contributes to the overall aesthetic of the timepiece. The case may include features such as a bezel, crown, and lugs, which allow the watch to be attached to a strap or bracelet. The size and shape of the case can vary greatly depending on the style of the watch, from small and sleek for dress watches to large and rugged for sports watches.
The caseback is the part of the watch case that covers the back of the watch. It can be screwed on or snapped on, and is typically made of metal or sapphire crystal. The caseback often has important information engraved on it, such as the brand name, model number, and water resistance rating. It also provides access to the watch’s movement, allowing for maintenance and repairs to be performed. Some watches have transparent casebacks, which allow the wearer to see the movement in action.
Central seconds hand refers to the second hand of a watch that is located at the center of the dial and rotates around the dial once every minute. It is the most common type of second hand found in watches and is used to indicate the passage of time in seconds. The central seconds hand is often accompanied by other hands, such as the hour and minute hands, which rotate around the dial to indicate the time of day. Some watches may also feature additional complications, such as a chronograph function, which allows the central seconds hand to be used as a stopwatch.
A ceramic bezel is a watch bezel made from a high-tech ceramic material. This type of bezel is highly scratch-resistant, durable, and lightweight. Ceramic bezels are often used in sports watches and diving watches because they are resistant to corrosion and can withstand exposure to saltwater. They are also available in a variety of colors, making them popular among watch enthusiasts who want a unique and stylish timepiece.
Chapter ring is a component of a watch dial that surrounds the hour markers and provides a clear indication of the time. It is usually a separate ring that is attached to the dial and features engraved or printed numerals or indices that correspond to the hours of the day. The chapter ring is typically made of metal or ceramic, and it can be decorated with various patterns or textures to enhance the aesthetic appeal of the watch. The chapter ring is an essential element of the dial design and helps to ensure accurate timekeeping and ease of use.
A chronograph is a type of watch that has a stopwatch function in addition to displaying the time. It typically has multiple sub-dials on the face of the watch that can measure elapsed time in seconds, minutes, and hours. Chronographs are often used in sports timing, aviation, and other activities that require precise time measurement. Some chronographs also have additional features such as tachymeters, which can be used to measure speed over a known distance. Chronographs can be operated using pushers on the side of the watch, which start, stop, and reset the stopwatch function.
D
Date function refers to a feature on a watch that displays the current date in addition to the time. The date is typically displayed in a small window on the watch face and is updated automatically at midnight. Some watches also have additional features such as the ability to display the day of the week or the month. The date function is a common feature on many watches and is useful for keeping track of important dates and events.
Day-date is a type of watch that displays both the day of the week and the date on the dial. The day of the week is usually displayed in full, while the date is typically shown in a numeral format. This feature is often found in high-end watches and is considered a practical and convenient feature for those who need to keep track of both the date and the day of the week. The day-date function is usually controlled by a separate crown or button on the watch, allowing the wearer to easily adjust both the day and date as needed.
A deployant clasp is a type of watch band buckle that provides a secure and adjustable closure. It consists of two parts: a folding metal plate that attaches to one end of the watch band and a hinged clasp that attaches to the other end. The clasp has a locking mechanism that snaps into place when the watch is fastened, ensuring that it stays securely on the wrist. Deployant clasps are often used on high-end watches and are considered more elegant and comfortable than traditional buckle closures.
Depth gauge is a feature found in certain types of watches, particularly those designed for diving. It is used to measure the depth of water during a dive. This feature typically consists of a scale or a rotating bezel with markings that indicate the depth in meters or feet. The depth gauge works by measuring the pressure exerted on the watch by the water, which is then converted into a depth reading. Some watches also have a maximum depth memory or a dive log function that records the depth and duration of each dive. Depth gauges are an important tool for divers to ensure their safety and monitor their dive time.
Digital display refers to a type of watch display that shows the time and other functions through digital numbers or symbols on a screen. This type of display is usually found on digital watches, which are powered by a battery and use electronic components to display the time and other features. Digital displays can show various types of information, including the time in different time zones, alarms, timers, stopwatches, and more. They are often easier to read than analog displays, especially in low light conditions, and offer a range of customization options for the user. Digital displays have become increasingly popular in recent years due to their convenience and versatility.
A diver’s watch is a type of watch that is specifically designed for underwater diving. It is water-resistant and can withstand the pressure of being submerged in water at great depths. Diver’s watches typically have a unidirectional rotating bezel that allows divers to keep track of their dive time, and they are often equipped with luminescent markers and hands for easy readability in low-light conditions. They also have a screw-down crown and case back to ensure water-tightness. In order to meet international standards for diver’s watches, they must be able to withstand water pressure up to a minimum of 100 meters (330 feet).
Dual time refers to a watch that displays two different time zones simultaneously. This feature is useful for travelers who need to keep track of the time in their home country and the country they are visiting. Dual time watches typically have two separate hour hands or a sub-dial that displays the second time zone. Some dual time watches also have additional features such as a world time function that displays the time in multiple cities around the world.
E
Ebauche refers to a partially completed watch movement that contains the basic components such as the main plate, bridges, wheels, and barrel, but lacks the regulating mechanism, escapement, and winding mechanism. Ebauche movements are often used by watchmakers as a starting point for creating their own unique timepieces or for assembling watches with custom dials and cases. They are also used by watch manufacturers as the foundation for their own movements, which are then finished and decorated to meet their specific standards. Ebauche movements are often sold to other watchmakers and manufacturers, making them an essential part of the watchmaking industry.
EOL (End of Life) indicator is a feature in some quartz watches that signals when the battery is running low and needs to be replaced. The indicator usually appears as a second hand that jumps every four seconds instead of smoothly sweeping across the dial. This is a warning to the wearer that the battery is about to die and needs to be changed soon. The EOL indicator helps prevent the watch from stopping unexpectedly and ensures that the timekeeping accuracy is maintained.
Equation of time refers to the difference between true solar time and mean solar time. True solar time is based on the position of the sun in the sky, while mean solar time is an average of the length of a day throughout the year. Due to the elliptical shape of the Earth’s orbit and its axial tilt, the length of a day can vary by up to 16 minutes throughout the year. The equation of time is often displayed on watches with a complication that shows the difference between true solar time and mean solar time. This allows the wearer to adjust the time on their watch to match the true solar time for their location.
The escapement is a mechanism in a watch that controls the release of energy from the mainspring to the balance wheel. It is responsible for regulating the movement of the watch and ensuring its accuracy. The escapement consists of several parts, including the escape wheel, pallet fork, and balance wheel. As the mainspring unwinds, it turns the escape wheel, which in turn moves the pallet fork back and forth. The pallet fork engages with the teeth of the escape wheel, causing the balance wheel to oscillate back and forth. This movement of the balance wheel is what drives the hands of the watch. The escapement is a critical component of a mechanical watch and is often considered the heart of the movement.
ETA movement refers to a type of mechanical movement used in watches that is produced by the Swiss company ETA SA Manufacture Horlogère Suisse. ETA movements are known for their accuracy, reliability, and durability, and are widely used in a variety of watch brands and models. ETA movements are available in various grades, ranging from basic to high-end, and offer a range of features such as automatic winding, chronograph functions, and date displays. ETA movements are considered to be some of the most widely used and trusted movements in the watch industry.
F
A flyback chronograph is a type of chronograph watch that allows for the quick and easy measurement of multiple time intervals. Unlike a traditional chronograph, which requires the user to stop, reset, and start the timer for each interval, a flyback chronograph allows the user to instantly reset the timer and start a new measurement with a single press of a button. This is particularly useful in situations where precise timing is critical, such as in aviation or motorsports. The flyback function is achieved through a complex mechanism that allows the chronograph hands to instantly reset and restart without interfering with the movement of the watch’s regular timekeeping function.
A folding clasp is a type of watch closure mechanism that consists of two metal plates that fold over each other to securely fasten the watch band around the wrist. The clasp typically has a release button that allows the wearer to easily open and close the watch band. This type of clasp is commonly used on metal watch bands, but can also be found on leather and rubber straps. The folding clasp provides a comfortable and secure fit for the wearer, ensuring that the watch stays in place throughout the day.
G
GMT (Greenwich Mean Time) is a term used in watches to refer to a time zone that is based on the mean solar time at the Royal Observatory in Greenwich, London. It is often used as a reference time for international communications, as it is the standard time used by the world’s time zones. GMT watches have an additional 24-hour hand on the dial that allows the wearer to track a second time zone in addition to the local time. This feature is especially useful for travelers and those who need to communicate with people in different parts of the world.
Grande complication refers to a type of high-end watch that features a combination of several complex and sophisticated complications, such as a perpetual calendar, minute repeater, chronograph, and moon phases. These watches are considered the pinnacle of watchmaking expertise and are typically produced in limited quantities by luxury watch brands. The term “grande” refers to the size and complexity of the watch, as well as the level of skill required to design and manufacture it. Grande complication watches are highly coveted by collectors and enthusiasts due to their rarity, intricacy, and technical excellence.
Guilloché is a decorative technique used on watch dials and other surfaces. It involves engraving intricate patterns onto the surface using a specialized machine called a rose engine. The result is a series of overlapping lines and curves that create a three-dimensional effect and catch the light in a unique way. Guilloché patterns can vary in complexity and are often used in combination with other decorative elements such as enamel or precious metals. The technique is often associated with high-end luxury watches and is considered a hallmark of fine craftsmanship.
H
Hacking seconds is a feature found in some mechanical watches that allows the seconds hand to be stopped when the crown is pulled out to set the time. This feature is useful for synchronizing the watch with a reference time signal, such as a radio or internet time signal. When the crown is pulled out, the balance wheel, which regulates the movement of the watch, is stopped, causing the seconds hand to stop moving. This allows for precise time setting and synchronization. Once the time is set, pushing the crown back in restarts the movement and the seconds hand begins to move again.
Hands refer to the small, pointed indicators on a watch dial that rotate around its center to indicate the time. Most watches have three hands: an hour hand, a minute hand, and a second hand. The hour hand is the shortest and indicates the hours, the minute hand is longer and indicates the minutes, and the second hand is the thinnest and indicates the seconds. Some watches may have additional hands for other functions, such as a chronograph or a GMT indicator. Hands can be made of various materials, such as metal, plastic, or even precious stones, and can be decorated with various designs or colors.
A helium escape valve is a feature found on some diving watches that allows helium gas to escape from the watch during decompression. When divers spend extended periods of time at great depths, they breathe a mixture of gases that includes helium. The helium molecules are small enough to penetrate the seals of the watch and can become trapped inside during decompression, causing the crystal or caseback to pop off. The helium escape valve is a one-way valve that allows the built-up helium to escape without compromising the watch’s water resistance. It is typically located on the side of the case and is operated by unscrewing the valve to release the gas.
Horology is the study and measurement of time and the art of making timepieces, including watches, clocks, and other timekeeping devices. It encompasses the science and technology of measuring time, as well as the history and evolution of timekeeping devices. Horology also includes the design, construction, and repair of watches and clocks, as well as the appreciation and collection of timepieces as works of art and cultural artifacts. Horologists are experts in the field of timekeeping and are skilled in the various techniques and technologies used in the creation and maintenance of watches and clocks.
I
Incabloc is a shock protection system used in mechanical watches. It is a small spring-loaded mechanism that surrounds the balance wheel, which is the part of the watch that regulates its accuracy. The purpose of the Incabloc system is to protect the balance wheel and other delicate components from damage caused by sudden impacts or jolts. The system works by allowing the balance wheel to move slightly when it encounters a shock, which helps to absorb the energy and prevent damage. Incabloc is a common feature in high-quality mechanical watches and is considered an important component for ensuring the longevity and accuracy of the timepiece.
Indices refer to the hour markers or numerals on a watch dial. These markers are typically used to indicate the hours, but can also be used for other time intervals such as minutes or seconds. Indices can come in various shapes and sizes, such as dots, bars, Arabic or Roman numerals, or even geometric shapes. They can be applied to the dial surface or incorporated into the design of the watch hands. Indices are an important aspect of watch design, as they help to improve readability and make it easier to tell time at a glance.
An integrated bracelet is a type of watch bracelet that is designed to be an integral part of the watch case, rather than a separate component that is attached to the case. This type of bracelet is typically made from the same material as the watch case, and is seamlessly integrated into the overall design of the watch. Integrated bracelets are often found on high-end sports watches and luxury timepieces, and are prized for their durability, comfort, and aesthetic appeal. They are also more secure than traditional watch bracelets, as they are less likely to come loose or break off.
J
Jewels in a watch refer to small synthetic rubies or sapphires that are used as bearings for the pivots of the watch’s gears. The use of jewels reduces friction and wear on the watch’s mechanical parts, increasing accuracy and longevity. The number of jewels in a watch can vary, with higher-end watches typically having more jewels. The jewel count is often used as a measure of a watch’s quality and complexity.
Jump hour is a type of watch display where the hour indication changes instantaneously at the top of each hour. Instead of a traditional hour hand that moves gradually around the dial, a jump hour watch has a digital or analog display that jumps to the next hour at the exact moment it changes. This type of display is often found in vintage or retro-inspired watches and can be a unique and eye-catching feature. Jump hour watches are also known as “digital hour” or “instantaneous hour” watches.
K
A kinetic watch is a type of watch that uses the movement of the wearer’s wrist to power the watch. The watch contains a rotor that spins with the movement of the wrist, which in turn powers a generator that charges a battery. This battery then powers the watch’s movement. Kinetic watches are known for their accuracy and reliability, as they do not require winding or battery replacement. They are also environmentally friendly, as they do not require disposable batteries.
L
Lugs are the protruding pieces on either side of a watch case that hold the watch strap or bracelet in place. They are typically located at the 12 o’clock and 6 o’clock positions on the watch case, and are designed to allow the strap or bracelet to be easily attached or removed. Lugs can vary in shape and size depending on the style of the watch, and can be made from a variety of materials such as stainless steel, gold, or titanium. They are an important component of the watch, as they provide both functionality and aesthetic appeal.
Luminous paint is a special type of paint that contains a phosphorescent material that glows in the dark after being exposed to light. This paint is often used on the hands and markers of watches to make them visible in low light conditions. The paint absorbs light during the day or when exposed to artificial light, and then emits light in the dark for a period of time. Luminous paint is commonly used on dive watches, pilot watches, and other timepieces that require visibility in low light conditions. The most commonly used material for luminous paint is a radioactive isotope called tritium, but non-radioactive alternatives are also available.
M
A mainspring is a coiled spring that is the primary power source of a mechanical watch movement. It is wound up by the user, either manually or automatically through the movement of the wearer’s wrist, and then slowly unwinds to power the watch’s gears and hands. The mainspring is typically made of a special alloy steel and is housed in a barrel, which helps regulate the release of its energy. The length and strength of the mainspring determine the watch’s power reserve, or how long it can run before needing to be wound again.
Manual winding refers to the traditional method of winding a mechanical watch by turning the crown manually. The crown is usually located on the side of the watch and is used to wind the mainspring, which powers the movement of the watch. Manual winding watches require regular winding, usually once a day, to keep accurate time. This method of winding is often preferred by watch enthusiasts for its traditional and tactile experience. However, it requires more attention and care than automatic or quartz watches, as over-winding or under-winding can damage the movement.
A marine chronometer is a highly accurate timepiece used for navigation at sea. It was first developed in the 18th century and was essential for determining longitude while sailing. The marine chronometer is designed to keep accurate time even in the harsh conditions of the sea, such as extreme temperature changes, vibrations, and humidity. It is typically housed in a sturdy, shock-resistant case and features a large, easy-to-read dial with a seconds hand. The marine chronometer is set to Greenwich Mean Time (GMT) and allows sailors to determine their longitude by comparing the local time with GMT. Today, marine chronometers are highly sought after by collectors and are considered a symbol of precision and craftsmanship.
A mechanical movement is a type of watch movement that uses a complex system of gears, springs, and other mechanical components to power the watch. Unlike quartz movements, which rely on batteries and electronic circuits, mechanical movements are powered by the winding of a mainspring, which stores energy and releases it slowly over time to power the watch’s hands and other functions. Mechanical movements are often prized for their precision, durability, and traditional craftsmanship, and can be found in a wide range of watch styles from classic dress watches to rugged sports models. However, they do require regular maintenance and may be more expensive than quartz watches due to their complexity and handcrafted nature.
Mineral crystal is a type of watch glass that is made from hardened mineral glass. It is a popular choice for watchmakers due to its durability and scratch-resistant properties. Mineral crystals are also relatively affordable compared to other types of watch crystals, such as sapphire crystal. However, they are not as scratch-resistant as sapphire crystal and can still be susceptible to scratches and cracks over time. Overall, mineral crystal is a reliable and cost-effective option for watch glass that provides good protection for the watch face.
A minute repeater is a complication in a mechanical watch that chimes the time in hours, quarters, and minutes upon activation. The wearer can activate the minute repeater by pressing a button or sliding a lever. The watch then plays a series of chimes that correspond to the current time. The hours are indicated by a low tone, the quarters by a combination of low and high tones, and the minutes by a high tone. Minute repeaters are considered one of the most complex and prestigious complications in watchmaking due to the intricate mechanics required to produce the chimes.
Moonphase refers to a complication in a watch that displays the current phase of the moon as it appears in the sky. This is typically achieved through the use of a small disc or aperture on the watch face that rotates to show the current phase of the moon, which can be either a full moon, half moon, or new moon. This feature is often found in luxury or high-end watches and is considered a useful tool for those who need to track the lunar cycle for various reasons, such as fishermen or farmers.
Mother-of-pearl is a material commonly used in watch dials and bezels. It is the iridescent inner layer of certain mollusk shells, such as oysters and abalone. The material is highly prized for its shimmering, rainbow-like appearance, which can vary depending on the angle of light and the thickness of the layer. Mother-of-pearl is often used in luxury watches to add a touch of elegance and sophistication to the design. It is a delicate material that requires careful handling and can be prone to cracking or chipping if not properly cared for.
Movement refers to the inner workings of a watch that keeps time and powers its functions. It includes all the parts that work together to keep the watch ticking, including the mainspring, balance wheel, escapement, and gear train. The movement can be either mechanical or quartz, with mechanical movements relying on a wound spring and intricate gear system to keep time, while quartz movements use a battery and electronic oscillator. The movement is often considered the heart of the watch and is a crucial component in determining its accuracy and reliability.
N
Numerals refer to the numbers on a watch dial that indicate the hours of the day. They can be Arabic (1, 2, 3, etc.) or Roman (I, II, III, etc.) and are often either printed or applied to the dial. Numerals can vary in size, font, and color, and can be accompanied by other design elements such as indices or hour markers. The style and placement of numerals can greatly affect the overall look and feel of a watch.
O
Oyster case is a type of watch case design that was introduced by Rolex in 1926. It is a hermetically sealed case that offers protection against water, dust and pressure. The Oyster case is made up of three parts: the middle case, the bezel and the case back. The middle case is made from a solid block of metal and is screwed tightly to the case back and bezel, creating a watertight seal. The bezel is usually made of a hard and scratch-resistant material such as ceramic or sapphire. The case back is also screwed tightly to the middle case to ensure a secure seal. The Oyster case is considered to be one of the most robust and reliable watch cases in the industry, making it a popular choice for diving and other water-related activities.
P
A pallet fork is a component in a mechanical watch that controls the release of energy from the watch’s mainspring to the balance wheel. The pallet fork is connected to the escape wheel and has two prongs that alternately engage with the teeth of the escape wheel, allowing the balance wheel to oscillate back and forth. The pallet fork is a crucial part of the watch’s escapement mechanism and is responsible for regulating the watch’s accuracy and precision. It is typically made of steel or another hard, durable material and is carefully designed and calibrated to ensure that it functions correctly.
A perpetual calendar is a complication in a watch that automatically adjusts the date display to account for the varying lengths of months and leap years. This means that the watch will display the correct date without needing to be manually adjusted, even during leap years. A perpetual calendar typically includes displays for the day, date, month, and year, and is considered a highly desirable and complex feature in luxury watches.
A power reserve indicator is a feature on a watch that displays the amount of energy left in the watch’s mainspring or battery. This indicator can be shown on the dial or through a separate subdial or window on the watch. It allows the wearer to know when the watch needs to be wound or charged to ensure accurate timekeeping. The power reserve indicator typically displays the remaining power in hours or days.
Pushers refer to the small buttons located on the side of a watch case that allow for the manipulation of various functions of the watch, such as starting, stopping, and resetting the chronograph or timing functions. They can also be used to adjust the time or date on certain watches. Pushers are typically made of metal or plastic and are designed to be easily operated with the thumb or finger. They are an important part of the functionality and design of many types of watches, particularly those with complex movements or features.
Q
Quartz movement refers to the type of movement used in a watch that is powered by a battery and a quartz crystal. The crystal oscillates at a precise frequency when an electric current is applied to it, which is then converted into a timekeeping signal. This signal is used to regulate the movement of the watch hands, resulting in highly accurate timekeeping. Quartz movements are known for their reliability and accuracy and are commonly found in both analog and digital watches. They are also low-maintenance, as they require little to no winding or adjustment.
Quickset date is a feature found in some watches that allows the wearer to easily adjust the date display without having to turn the watch hands through a full 24-hour cycle. With a quickset date function, the wearer can simply pull out the crown (the small knob on the side of the watch) to a certain position and then turn it to set the correct date. This is a convenient feature that saves time and effort compared to traditional date-setting methods. Quickset date is commonly found in higher-end watches and is often considered a useful feature for frequent travelers or those who frequently need to adjust the date display.
R
Rattrapante, also known as a split-seconds chronograph, is a type of chronograph watch that has an additional hand, called the split-seconds hand, that can be stopped independently of the main chronograph hand. This allows the user to time multiple events that start at the same time but have different durations. The split-seconds hand can be stopped to record the time of one event while the main chronograph hand continues to time the overall duration. Once the split-seconds hand has been recorded, it can be quickly reset to catch up with the main chronograph hand and start timing the next event. The rattrapante is a complex and highly sought after complication in watchmaking, requiring precise engineering and assembly.
A regulator is a type of watch movement that features a separate dial or sub-dial for each of the three main timekeeping functions: hours, minutes, and seconds. The hour dial is typically located at the top, while the minute dial is in the center and the second dial is at the bottom. The purpose of a regulator watch is to provide a high degree of accuracy by allowing the user to easily adjust each of the individual timekeeping functions independently. This type of watch was originally used by watchmakers and clockmakers to set and regulate other timepieces, but has since become a popular design for luxury watches.
A complication in a mechanical watch that chimes the time on demand. There are two types of repeaters: the minute repeater and the quarter repeater. The minute repeater chimes the hours, quarters, and minutes, while the quarter repeater chimes only the hours and quarters. The chimes are activated by a pusher or slide on the case, and the number of chimes corresponds to the time indicated by the watch’s hands. Repeater watches are highly valued for their intricate mechanics and the skill required to create them.
Retrograde is a watch complication that displays time in a unique way. Instead of a traditional circular or linear display, retrograde watches feature a semi-circular or arc-shaped display that uses a moving hand or marker to indicate time. The hand or marker moves along the arc and then jumps back to the beginning once it reaches the end, creating a retrograde motion. Retrograde displays can be used for various functions, such as indicating the date, day of the week, or seconds. This type of display adds a unique and eye-catching element to a watch’s design.
A rotor is a component found in automatic watches that helps to wind the watch’s mainspring. It is a disc-shaped weight that is connected to the movement and rotates freely with the movement of the wearer’s wrist. The rotor’s movement causes the winding mechanism to turn, which in turn winds the mainspring. This eliminates the need for manual winding of the watch. The rotor is typically made of metal and can be seen through the watch’s caseback. Some watch manufacturers use decorated rotors to add aesthetic appeal to their watches.
S
Sapphire crystal is a type of watch crystal that is made from synthetic sapphire, a material that is second only to diamond in terms of hardness. This makes it highly scratch-resistant and durable, making it a popular choice for high-end watches. Sapphire crystal is also highly transparent, allowing for excellent visibility of the watch face and hands. It is often used in luxury watch brands and is considered a premium feature due to its high cost.
A screw-down crown is a type of watch crown that is threaded and screws into the case to create a water-tight seal. It is commonly found on diving watches and other timepieces that require a high level of water resistance. To adjust the time or date on a watch with a screw-down crown, the user must first unscrew the crown to release it from the case, make the necessary adjustments, and then screw it back down to re-seal it. This mechanism helps to prevent water from entering the watch and damaging the movement.
Screw-down pushers refer to buttons or pushers on a watch that are designed to be screwed down to ensure water resistance. This feature is commonly found on diving watches and chronographs, where the pushers need to be protected from water or moisture. By screwing down the pushers, the watch becomes more resistant to water and can be used for diving or other water activities. The screw-down mechanism is typically found on the side of the pushers and can be twisted to lock the pushers in place. To use the pushers, the user needs to unscrew them first, then press them to activate the desired function. Once the user is done, they need to screw down the pushers again to ensure water resistance.
Self-winding movement, also known as an automatic movement, is a type of mechanical watch movement that winds itself automatically as the wearer moves their wrist. This is achieved through a rotor, a weighted metal disc that rotates with the movement of the wrist, which in turn winds the watch’s mainspring. This eliminates the need for manual winding and ensures that the watch remains powered as long as it is worn regularly. Self-winding movements are highly valued among watch enthusiasts for their convenience and reliability.
Shock resistance refers to a watch’s ability to withstand sudden impacts or vibrations without damaging its internal mechanisms. This is achieved through the use of shock-absorbing materials and design features such as a balance wheel cage or a movement mount that can absorb shocks and protect the delicate components of the watch. Shock resistance is an important feature for watches that are designed to be worn during active or outdoor activities, as they are more likely to be subjected to sudden impacts or jolts.
A watch that has a transparent or partially transparent dial and case, revealing the inner workings and intricate mechanisms of the watch. The movement of the watch is visible through the front and back of the case, showcasing the gears, springs, and other components. Skeleton watches are often highly prized by watch enthusiasts for their intricate design and technical complexity.
Slide rule bezel is a feature found on some pilot or aviation watches that allows for complex calculations to be made. The bezel is marked with logarithmic scales that can be used to perform mathematical operations such as multiplication, division, and conversion of units. The bezel can be rotated and aligned with certain markers on the watch dial to perform the desired calculation. This feature was particularly useful for pilots in the days before electronic calculators and computers became widely available. Today, slide rule bezels are often included on pilot watches as a nod to their aviation heritage.
A solar-powered watch is a type of watch that harnesses energy from the sun through a solar panel located on the watch face. The energy is stored in a rechargeable battery which powers the watch. Solar-powered watches are environmentally friendly and do not require regular battery replacements. They are also known for their accuracy and reliability as they run on a constant and consistent power source. Some solar-powered watches also have additional features such as a power reserve indicator and a low battery warning.
A split-seconds chronograph, also known as a rattrapante chronograph, is a type of stopwatch that has two second hands that can be used to time multiple events simultaneously. The first second hand, also called the main hand, is started and stopped like a regular chronograph. The second hand, known as the split-seconds hand, can be stopped independently of the main hand to record intermediate times while the main hand continues to run. This allows the user to time multiple events that start at the same time but have different durations. The split-seconds hand can be stopped and started again to catch up with the main hand. Split-seconds chronographs are often used in sports timing, particularly in track and field events. They are also popular among collectors due to their complexity and rarity.
Stainless steel is a type of steel that is highly resistant to corrosion and staining. It is composed of iron, carbon, and at least 10.5% chromium, which forms a protective layer on the surface of the steel when exposed to oxygen. Stainless steel is commonly used in the manufacturing of watch cases, bracelets, and other components due to its durability and resistance to wear and tear. It is also easy to clean and maintain, making it a popular choice for everyday wear.
A sub-dial is a smaller dial on a watch face that displays additional information or functions beyond the main timekeeping display. Sub-dials are typically found on chronograph watches, which feature stopwatch functions, and can display measurements such as elapsed time, seconds, minutes, and hours. They can also be used to display other information such as the date, day of the week, or a secondary time zone. Sub-dials are often located within the main dial and may have their own hands or markers to indicate the relevant information.
Super-LumiNova is a type of luminescent material used on watch dials, hands, and indices to provide visibility in low-light conditions. It is a non-radioactive, non-toxic substance that is charged by exposure to light and emits a bright glow in the dark. Super-LumiNova is commonly used on high-end watches and is available in various colors. It is known for its long-lasting and bright luminosity, making it a popular choice for divers and other outdoor enthusiasts.
Swiss Made refers to a label that is given to watches that are manufactured in Switzerland and meet certain criteria set by the Swiss government. The label is an indication of the watch’s high quality and precision, as Switzerland is known for its expertise in watchmaking. To qualify for the Swiss Made label, at least 60% of the watch’s production costs must be incurred in Switzerland, and the watch’s movement must be Swiss-made. Additionally, the final inspection of the watch must take place in Switzerland. Swiss Made watches are highly sought after and are often associated with luxury and high-end timepieces.
Swiss movement refers to the mechanism inside a watch that is made in Switzerland. Swiss movements are known for their precision, durability, and reliability. They are often considered to be the highest quality movements in the watch industry. Swiss movements are typically made by skilled watchmakers using traditional techniques and high-quality materials, which contributes to their reputation for excellence. Many luxury watch brands use Swiss movements in their watches, as they are highly sought after by collectors and enthusiasts. Overall, a Swiss movement is a mark of quality and craftsmanship in the world of watches.
Synthetic ruby refers to a man-made material that is used in the construction of watch movements. It is a type of synthetic corundum that is created by melting aluminum oxide powder and adding small amounts of other materials to create the desired color and clarity. Synthetic ruby is extremely hard and durable, making it an ideal material for bearings and other critical components in watch movements. It is also resistant to wear and corrosion, which helps to ensure the accuracy and longevity of the watch. Synthetic ruby is often used in high-end watches and is considered a mark of quality and precision.
T
A tachymeter is a feature found on some watch bezels or dials that allows the wearer to measure speed or distance over a fixed period of time. The tachymeter scale is typically marked in units per hour and is used in conjunction with a chronograph function to measure the time it takes to travel a certain distance. For example, if a car travels one mile in 30 seconds, the tachymeter scale can be used to determine the car’s speed in miles per hour. Tachymeters are commonly found on sports watches and are a useful tool for athletes or anyone who needs to measure speed or distance.
Telemeter is a watch function that measures the distance between the wearer and an event that can be both seen and heard, such as lightning and thunder. It uses a scale on the watch dial to calculate the distance by measuring the time between the event and the sound reaching the wearer. The telemeter function is commonly found on chronograph watches and is often used in military and outdoor activities.
Titanium is a highly durable and lightweight metal that is commonly used in the construction of high-end watches. It is known for its strength, resistance to corrosion, and hypoallergenic properties. Titanium watches are often preferred by athletes and outdoor enthusiasts due to their durability and resistance to scratches and damage. They are also popular among those with sensitive skin as they are less likely to cause skin irritation or allergic reactions. Despite its strength, titanium can be easily shaped and polished, making it a popular choice for watchmakers who want to create sleek and modern designs.
A tool watch is a type of watch that is designed and built to serve a specific purpose or function beyond simply telling time. These watches are often designed to withstand harsh environments and extreme conditions, and may have additional features such as water resistance, shock resistance, and durability. Some common types of tool watches include dive watches, pilot watches, and military watches. Tool watches are often favored by adventurers, outdoor enthusiasts, and professionals who need a reliable timepiece that can withstand the demands of their work or hobbies.
Tourbillon is a complex and intricate mechanism found in high-end luxury watches. It is designed to counter the effects of gravity on the watch’s movement, which can cause inaccuracies in timekeeping. The tourbillon consists of a rotating cage that holds the watch’s balance wheel, hairspring, and escapement. The cage rotates once per minute, which helps to average out the effects of gravity on the movement. Tourbillons are considered one of the most prestigious and coveted features in luxury watchmaking, and are often found in highly complicated and expensive timepieces.
Tritium is a radioactive isotope of hydrogen that is used in some watches to create luminous markings on the dial and hands. Tritium gas is sealed in small glass tubes or capsules, which are then coated with a phosphorescent material. When the tritium decays, it emits electrons that excite the phosphorescent material, causing it to glow. This creates a long-lasting, self-illuminating effect that is visible in low-light conditions. Tritium is considered safe for use in watches because the amount of radiation emitted is very low and the gas is contained within the capsules. However, it is important to handle tritium watches with care and dispose of them properly at the end of their lifespan.
U
A unidirectional bezel is a rotating bezel on a watch that can only be turned in one direction, typically counterclockwise. It is commonly found on dive watches and is used to measure elapsed time underwater. The bezel is marked with minute markers and a triangle or other indicator, which can be aligned with the minute hand to mark the start time of a dive. The unidirectional design ensures that if the bezel is accidentally moved, it will only show a shorter elapsed time, rather than a longer one, which could be dangerous for a diver.
V
Valjoux movement refers to a type of mechanical movement commonly used in chronograph watches, which are timepieces that can measure elapsed time. The Valjoux movement is known for its reliability and precision, and is highly regarded among watch enthusiasts. It was developed by the Swiss watchmaker Valjoux SA and is characterized by its three subdials, which display the chronograph functions of minutes, seconds, and hours. The movement is also known for its smooth operation and ease of use, making it a popular choice among watchmakers. Overall, the Valjoux movement is a high-quality and respected movement that has helped to define the chronograph watch category.
Vibration in watchmaking refers to the oscillation or movement of a watch’s balance wheel, which is responsible for keeping time. The balance wheel vibrates back and forth at a specific frequency, typically measured in Hertz, or cycles per second. The vibration rate of a watch can vary depending on the specific movement and design, but generally ranges from 2.5 to 5 Hz. A higher vibration rate can result in increased accuracy and precision, but can also increase wear and tear on the watch’s components. Vibration is a crucial aspect of a watch’s timekeeping function, and is often adjusted and regulated by watchmakers to ensure optimal performance.
W
Water resistance refers to the ability of a watch to resist water penetration. It is typically measured in meters or atmospheres (ATM) and indicates the depth to which a watch can be submerged without water damage. A watch with a water resistance rating of 30 meters, for example, can withstand splashes of water but should not be worn while swimming or diving. It is important to note that water resistance is not a permanent feature and can decrease over time due to wear and tear or damage to the watch. It is recommended to have the water resistance of a watch checked regularly by a professional to ensure its effectiveness.
The wheel train is a key component of a mechanical watch movement that transmits power from the mainspring to the escapement, which regulates the movement of the watch’s hands. It consists of a series of gears, or wheels, that are connected by pivots and rotate on axles. The wheel train typically includes the center wheel, third wheel, fourth wheel, and escape wheel. The center wheel is connected to the mainspring barrel, while the fourth wheel is connected to the minute hand. The escapement, which is located between the third and fourth wheels, releases the power from the wheel train in small, regulated intervals, allowing the watch to keep accurate time. The wheel train is a crucial part of a watch’s movement and must be precisely engineered and assembled to ensure accurate timekeeping.
World time refers to the ability of a watch to display the time in multiple time zones around the world. This feature is particularly useful for travelers or individuals who frequently communicate with people in different time zones. World time watches typically have a rotating bezel or inner ring that displays the names of different cities or time zones, and the watch hands will adjust accordingly when the user selects a different location. Some world time watches also have a 24-hour dial or a second time zone sub-dial for additional functionality.
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A yacht timer is a specialized chronograph watch designed for use in sailing and yacht racing. It typically features a countdown timer that can be set to a specific duration, such as the start of a race, and then counts down to zero. The watch may also have additional features like a regatta timer, which can be used to time the start of a race with multiple boats. Yacht timers may also be water-resistant and have additional features like a rotating bezel for measuring elapsed time.
Z
Zulu time, also known as Coordinated Universal Time (UTC), is a standardized timekeeping system used in aviation, military, and other industries that require precise time synchronization. It is based on the 24-hour clock and uses a time zone offset of zero, meaning it is the same time everywhere in the world. Zulu time is often displayed on watches and clocks with a second time zone function, and is indicated by the letter “Z” or “UTC” on the dial.