|Analog Display (return to top)
The time is indicated by a pair of hands (hour and minute) that move around the dial.Antimagnetic (return to top)
Because the earth’s magnetic field can interfere with a mechanical watch’s oscillation and escapement, parts may be made from non-magnetic metals, or an entire movement may be enclosed within a case made of a highly conductive alloy, which prevents magnetic buildup on the inside. A watch may be described as antimagnetic if within a magnetic field of 4,800 A/m (amperes per meter) it continues to run with no more deviation than 30 seconds per day.Anti-Reflective Crystal (return to top)
A mineral or sapphire crystal that has been coated on one or both sides with a solution that lessens reflections and glare. Viewed from the front, the crystals are virtually invisible, while a slight blue tint may be noted from an angle.Automatic (Movement) (return to top)
A precise, intricate system of tiny gears and springs which use mechanical energy to operate. These watches have a mainspring which is wound either by hand or by “automatic movement” (self winding), which uses the motion of the wearer for its energy supply. The spring power is then transferred to the hands of the watch via a precise timing mechanism known as a balance.Balance (return to top)
The most critical moving part of a mechanical watch movement because it regulates the speed of the movement. This includes the balance wheel that oscillates and the balance lever. The lever is the ratchet mechanism that makes the characteristic ‘tick’ sound as it converts the balance wheel’s motion into the precisely regulated increments of movement that run the watch.Balance spring, also Hairspring (return to top)
A very fine, elastic spring which allows the balance to make regular oscillations; its length determines the duration of each oscillation.Bezel (return to top)
The outer rim that encircles the dial, holds the crystal in place, and may also move unidirectionally (moves in one direction only) or bidirectionally (moves both clockwise and counterclockwise) for measurement purposes, particularly on dive watches, or to indicate a second time zone.Blued Screws (return to top)
Screws that are “blued” in color either by heat or chemicals for decorative purposes.
Bridge (return to top)
A metal plate secured by screws to the main plate and under which the pivots of the wheels and pinions turn. It forms a frame, and the other parts are mounted inside it—part of the ébauche.
Cadrature (return to top)
Extra mechanisms under the dial in complicated timepieces (e.g. chronograph mechanism, minute repeater striking mechanism, or calendar mechanism).
Caliber (return to top)
French term referring to a gauge or size and also “to calibrate.” Also refers to the numerical progression of models in watch jargon.
Chronograph (return to top)
A watch with two independent time systems: one indicates the time of day, and the other measures brief intervals of time. These measurements can be seen on the subdials, or counters, which may register seconds, minutes, and even hours, and are started and stopped at the press of a button (stopwatch feature).
Chronometer (return to top)
The term chronometer was first used to describe timepieces accurate enough for ship navigation. Now it refers to a watch which has undergone a series of severe precision tests and been certified by standards set by the COSC. The typical men’s mechanical watch movement must have stayed within -4 to +6 seconds of variation per day during the COSC tests at various temperatures and positions. A chronometer certificate is not a guarantee of future accuracy. Movements that are not certified may still exceed the COSC standards—the manufacturer may simply have chosen to bypass the expense of the certification process. A watch does not have to be a chronograph to achieve a chronometer rating.
Column wheel (return to top)
An upright wheel in a chronograph that acts as a sliding link to operate the various levers that set a chronograph in motion.
Côtes de Genève (return to top)
Also called Geneva stripes, this traditional Swiss surface decoration is a series of parallel undulating lines, like waves, which is applied to flat movement components and frequently used to embellish superior quality movements.
Complication (return to top)
A watch with other functions besides time-keeping. For example, a chronograph is a watch complication. Other complications coveted by watch collectors include: minute repeater, tourbillon, perpetual calendar, or split second chronograph.
COSC (also see Chronometer) (return to top)
The Controle Officiel Suisse des Chronometeres (COSC) established themselves in 1973 as the official testing and certification control board. Now, only a watch whose movement has been certified by COSC can be called a chronometer.
Crown (return to top)
The knurled knob on the outside of a watch case – often at the 3 o’clock position – used for winding, and when pulled out, setting the time and calendar indications.
Crystal (return to top)
A transparent cover that protects the watch dial and is usually made of mineral glass, synthetic sapphire, or plexiglass. Plexiglass is least likely to shatter and most likely to be scratched. Mineral crystal is resistant to scratching and shattering. Sapphire is the most expensive and most scratch resistant, but its hardness makes it brittle and more easily shattered.
Deployant, or Deployment, or Tang (return to top)
A buckle that fastens to the watch strap and opens and fastens using hinged extenders.Â
Depth Alarm (return to top)
An alarm on a divers’ watch that sounds when the wearer exceeds a pre-set depth.
Dial (return to top)
The face of the watch.
Digital Display (return to top)
Time is indicated by numerals (as through an aperture on a mechanical timepiece) rather than the movement of a hand.
Ébauche (return to top)
A “raw” base watch movement. Often manufacturers will make custom modifications to the base movement to add complications, decorate the movement, and electroplate (PVD) or upgrade certain parts for added durability. The term usually refers to an assembled movement without the escapement, balance, hairspring, and mainspring.
Escapement (return to top)
A mechanism that functions to suspend the gears’ motion at regular intervals and transfers energy from the mainspring to the balance wheel.
ETA (return to top)
ETA SA Manufacture HorlogÃ¨re Suisse is a leading manufacturer in Switzerland for movements used in many Swiss watch brands. This member of the Swatch Group derives its name from its slogan: Elegance, Technology, Accuracy.
Fly-back Hand (return to top)
In a chronograph with analog display, an additional centre second hand which can remain superimposed on the other one as it moves, can be stopped independently, and then made to “fly back” so as to catch up with the other hand. It can be stopped and reset to zero together with the other hand and is used to record lapsed time. A flyback function prevents timing delays when measuring the legs of a journey.
Frequency (return to top)
The number of oscillations per second or vibrations per hour of a mechanical watch. The balance makes a to-and-fro movement at a given frequency (two vibrations). The higher the frequency, the more accurate the watch. Most modern mechanical watches vibrate at a frequency of 18,000 or 28,800 VpH (Vibrations per Hour).
Gear Train (return to top)
Device that transmits power through 4 toothed wheels from the Mainspring to the Escapement.
Geneve Seal (return to top)
An exacting quality seal of prestige given to watches by the Bureau de controle Facultatif des Montres de l’Etat de Geneva. To qualify, in addition to matching all the criterion required to be labeled a “Swiss Made” watch, a timepiece must be assembled and adjusted within the Canton of Geneva. Each caliber must meet 12 technical and aesthetic criteria. The Geneve Seal, which depicts the coat of arms of the City of Geneva, was established in 1886 by a guild plagued with counterfeit products to indicate independent origin and guarantee superior quality.
Geneva Waves (return to top)
Striped ornamentation often decorating bridges and rotors of fine mechanical timepieces.
GMT (return to top)
Greenwich Mean Time. The standard for timekeeping that was introduced in England in 1880 and used as the basis for calculating standard time throughout the world.Â It reflects the mean solar time along the Earth’s prime meridian, which runs through the Greenwich Observatory outside of London, England.
Guilloché (ge-yosh’ ay) (return to top)
The term ‘guilloché’ (named after the French engineer Guillot, who invented a machine that scratched fine patterns into metallic surfaces) means ‘engine-turned’ and refers to a surface decoration usually applied to the dial or rotor of a watch. Generally, this design consists of wavy and interlacing lines that cross at regular intervals. The most classical form of the guilloché motif is the ‘barley-corn’ pattern. In general, however, most guilloched dials are decorated with a pattern consisting of radiating scallops or festoons with twelve spokes known as ‘flinqué’.
Hacking Seconds (return to top)
The feature on many modern mechanical movement watches that stops the second hand when you pull the crown all the way out to set the time. This makes it much easier to set a mechanical watch precisely to the second when synching with a time signal or known accurate clock.
Hairspring, also Balance Spring (return to top)
A very fine, elastic spring which allows the balance to make regular oscillations; its length determines the duration of each oscillation.
Hands (return to top)
The pointing devices anchored at the center which circle around the dial to indicate hours, minutes, seconds and any other special features of the watch.
Horology (return to top)
The science and art of measuring time.
Incabloc® (return to top)
The most commonly used brand of shock absorber system used in mechanical watches, which serves to dampen shocks to balance-staff pivots.
Jewel (return to top)
Synthetic ruby or sapphire gems used for their durability and resistance to temperature changes and set inside a movement for shock-absorption and friction reduction. These synthetic gems do not add monetary value to a watch and quantity does not indicate anything other than the more jewels, the more complicated the movement is likely to be.
Kinetic (movement) (return to top)
The rotor, which is activated by the movement of your arm, turns a mini-generator which generates electricity that is then stored in the battery.
Lugs, also Horns (return to top)
The four protrusions on a typical watch case used to attach a bracelet or strap.
Mainspring (return to top)
A coiled, flat spring that provides power to drive the gear train. In use since the 15th century, these springs are long, elastic, spirally wound strips of Nivaflex (an elastic and wear-resistant alloy) encapsulated within the barrel. They achieve the greatest torque when fully wound, and the torque is kept relatively constant by the continuous rewinding during the movement of the wearer. As the tension in the spring decreases, the amount of torque decreases and eventually affects the running of the watch, which is why a watchwinder is favorable when the watch is not being worn (and thus not being wound).
Manufacture (return to top)
A word derived from the Latin meaning “made by hand,” it refers to a factory that produces the parts of the ébauche (raw movement) and then assembles it into a functional timepiece. A brand may be called a manufacture if they make the components and assemble at least one complete caliber.
Mineral (crystal) (return to top)
Heat-tempered glass used as a cover for watch dials. More scratch-resistant than plexiglass and often reinforced with a scratch-resistant coating.
Minute Repeater (return to top)
A special complication found on very high-end mechanical watch that chimes (“repeats”) on the hour or intervals of an hour at the press of a button or slide. The mechanism strikes either or both of two sounding springs to produce an audible chime which corresponds to the time.
Moonphase (return to top)
An indication that shows the moon’s current phase by means of a disc that rotates beneath a small, specially shaped aperture. A regular rotation of the moon is 29 days, 12 hours, and 44 minutes. As the days of the month pass, one of two moon faces painted on the disc reveals the phase of the actual moon.
Mother of Pearl (return to top)
A reflective, iridescent, and variable material that ranges in tones from pearlescent white to shimmering blue and violet and is often used on women’s watch dials.
Movement (return to top)
The complete inner mechanism of a watch, which includes the ébauche, the regulating parts, and all other components (springs, jewels, screws, etc).
Oscillation (return to top)
The travel of the balance wheel from one extreme to the other and back again. See Vibration.
Perlage, or Perlée (return to top)
Surface decoration on metal comprised of an even pattern of partially overlapping, lightly cut circular polishings, applied with a quickly rotating peg. Its original use was to prevent dust and dirt from gathering on a movement’s plates, and today is used as a traditional form of décor which imparts a shading that’s pleasing to the eye.
Perpetual Calendar (return to top)
A complication feature, comprised of approximately 100 component parts, that compensates for the various lengths of months and leap years to display an accurate date. Current perpetual calendars are programmed to be accurate through the year 2100.
Pinion (return to top)
A watch part which is the seat upon which a wheel is riveted and generally features 6-14 leaves (teeth), the shank, and the pivots.
Pivot (return to top)
A fixed bearing, typically atop the pinion.
Plexiglass, or Acrylic crystal (return to top)
A clear, lightweight plastic used as a cover for watch dials. The least likely to shatter but prone to scratches; however, shallow scratches can easily be buffed out. New styles are more scratch resistant and are often used on watch styles that do not have a bezel or which have a bezel lower than the crystal.
PVD (return to top)
Physical Vapor Deposition. During this process, a thin film of vaporized metal is applied in a vacuum to the watch case and bracelet to enhance the properties and performance of the stainless steel surface.
Quartz (return to top)
A watch movement that combines an integrated circuit, miniature battery, and a quartz crystal oscillator which vibrates at a high frequency and which reveals superior accuracy of timekeeping.
Retrograde (return to top)
A display in which a hand moves across a number arc or segment of the dial to indicate the hour or the date. When the hand reaches the end of the arc, it returns instantly to its beginning position.
Rotor (return to top)
A half-disc of heavy metal which is made to rotate inside the case of an automatic watch by gravity and the movements of the wearer’s arm, and which continually wind the mainspring.
Sand-blasting (return to top)
Creating a granular metal finish by using a high-pressure jet of sand.
Sapphire (crystal) (return to top)
A very hard, transparent material made by crystallizing aluminum oxide at high temperatures which is then used as a transparent cover on watch dials. Chemically, it’s the same as sapphire gems used in jewelry, but without the coloration. Sapphire is approximately 3 times harder than mineral crystal and 20 times harder than plexiglass. Sapphire measures 9 on the Mohs Hardness Scale (Diamond measures 10, the highest rating), and it’s the most scratch-resistant crystal used on watches, though it can be scratched by a diamond or any material that incorporates silicon carbide, which is sometimes found in simulated stone surfaces for furniture or walls.
Shock Resistance (return to top)
An American government standard of durability which means that the watch can survive a drop of three feet onto a wooden floor. The “shock-protection” in watches is in the form of a tiny spring that holds the balance staff jewels in place, which ensures a slight amount of give – not enough to disrupt the operation of the watch for more than a moment, but enough to prevent the balance pivots or cap jewels from jarring. The most well-known manufacturer is Incabloc®.
Split-seconds Chronograph (return to top)
Also known as rattrapante, this watch has two second hands, one of which can be blocked with a special dial train lever to indicate an intermediate time while the other continues to run. When released, the split-seconds hand jumps ahead to the position of the other second hand. These are particularly useful for timing simultaneous phenomena starting at the same time but which last for different durations, such as sporting events in which several competitors are taking part.
Spring Bar (return to top)
A spring-loaded metal bar mounted between the case lugs (horns) and used to attach a strap or bracelet.
Straight Spring bar and Flanged Spring bar (easier to remove).
Spring Drive (return to top)
An automatic movement introduced in 2005 by Seiko which has the distinction of not having an escapement, which eliminates the friction caused by that component and allows the hands on Spring Drive watches to glide. The patented “Magic Lever” system is more stable and precise than the traditional escapement and manages the mechanical, electrical, and electro-magnetic energy generated by the mainspring.
Stop Second (return to top)
A mechanism used to set time precisely to the second. Pulling out the crown temporarily suspends the movement and stops the second hand automatically for the time to be set.
Subdial, or Subsidiary Dial, or Counter (return to top)
Small dials placed inside the main dial on a watch face and used for any of several purposes, such as keeping track of elapsed minutes or hours on a chronograph, or indicating the date.
Sweep Second Hand (return to top)
The central second hand, or on some chronographs, a hand indicated upon a subdial.
Swiss-Made (return to top)
A term from Swiss law which requires that the assembly work on the movement (the motor of the watch) and on the watch itself (fitting the movement with the dial, hands and the various parts of the case) should be carried out in Switzerland, along with the final testing of the movement. It also requires that at least 50% of the components of the movement must be manufactured in Switzerland. The watch case and separate or detachable items, such as watch bracelets, do not have to be manufactured in Switzerland. But the “foreign” parts must be delivered to Switzerland unassembled, with actual assembly of them into a watch occurring on Swiss soil.
Tachymeter (or Tachometer) (return to top)
A distance scale built into a watch and displayed on the bezel, inside rim, or dial, which allows a wearer to measure speed in miles or kilometers per hour. For example, if one kilometer (1,000 meters) was covered in 20 seconds, the tachymetric scale shows a speed of 180 km/h.
Tank (return to top)
A rectangular watch design with heavier bars on either side of the dial, inspired by the tank tracks of World War I and first created by Louis Cartier.
Telemeter (return to top)
A chronograph scale used to measure the distance the wearer is from an event, particularly lightning.
Tonneau (return to top)
A watch design with a barrel-shaped case with two convex sides.
Tourbillon (return to top)
Considered to be one of the most ingenious horological devices ever created, the tourbillon (pronounced TOOR’ bee on, the word is French for “whirlwind”) was invented by Abraham Louis Breguet in 1795 and patented in 1801. It consists of a mobile carriage which carries all the parts of the escapement and the balance in the center. The case makes one revolution per minute to compensate for errors that may have accumulated in the vertical position. The main purpose is to eliminate errors of rate due to the earth’s gravity and compensate for the watch’s change of position during use (face up, face down, on side, etc.).
Vibration (return to top)
Movement (the beat, or “tick”) of a pendulum or other oscillating element, limited by two consecutive extreme positions. The balance of a mechanical watch generally makes five or six vibrations per second (i.e. 18,000 or 21,600 per hour), but that of a high-frequency watch may make seven, eight or even ten vibrations per second (i.e. 25,200, 28,800 or 36, 000 per hour). The higher the number of vibrations, the smoother the watch will run.
Valjoux (return to top)
Named for Vallée de Joux, or “Joux Valley,” Valjoux is a Swiss manufacturer of mechanical watch movements, primarily chronographs, and is part of ETA and a member of the Swatch Group.
Watch Winder (return to top)
A powered device that keeps a watch wound and running when not on a wearer’s wrist.
Water Resistance (return to top)
A rating which is an evaluation of how much water pressure the moisture seals on a watch can withstand. Most watches are rated to 50 meters, which is more than most of us will ever need, and Diver’s watches must be rated at 100 meters, minimum. Water resistance is also measured in ATM, or atmospheres. One atmosphere is equivalent to 10 meters. The atmosphere rating is essential if you mountain climb, parachute, sky-dive, hang-glide, or ski, since pressures change above and below sea level. Please note that the crown must be completely sealed for the water resistance to be effective, and resistance applies to the case only, not the strap. Below is a handy rating guide:
Water resistant 3ATM, 30 meters (100 feet) — Will withstand splashes of water or rain but should not be worn while washing dishes, swimming, or diving.
Water tested to 5 ATM, 50 meters (165 feet)—Suitable for wearing while washing dishes, showering, or swimming in shallow water.
Water tested to 10 ATM, 100 meters (330 feet)—Suitable for swimming or snorkeling.
Water tested to 15 ATM, 150 meters (500 feet)— Suitable for snorkeling.
Water tested to 20 ATM, 200 meters (660 feet)—Suitable for skin diving.
Diver’s to 150 meters—Meets ISO Standards and is suitable for scuba diving.
Diver’s to 200 meters—Meets ISO Standards and is suitable for scuba diving.