Screw – Lock Your Language
Our guide to watch terminology continues to shine light on the language of watches as we cover M – S
Glossary by John Galt
Main Plate: Base plate on which all the other parts of a watch movement are mounted.
Mainspring: The driving spring of a watch or clock, contained in the barrel.
Manual Wind: A manual wind watch normally needs to be wound every day by the crown in order to run. When fully wound they will run between 36 and 72 hours depending on the model. They are produced by the major houses in Switzerland. Some of the most beautiful pieces made today are manual wind; with exhibition backs becoming very common, it’s nice to view the active movement without a rotor in the way.
Measurement Conversion: A feature, usually consisting of a graduated scale on the watch’s bezel, that lets the wearer translate one type of measurement into another – miles into kilometers, for instance, or pounds into kilograms.
Mechanical Movement: A movement based on a mainspring which is wound by hand(see manual wind); when wound, it slowly unwinds the spring in an even motion. An automatic mechanical requires no winding because of the rotor, which winds the mainspring every time you move your wrist.
Micron: Unit of measurement of the thickness of the gold-coating. 1 micron = 1/1000mm.
Military or 24-hour time: When time is measured in 24-hour segments. To simply convert 12-hour time into 24-hour, add 12 to any p.m. time. To convert 24-hour time back into 12-hour time, subtract 12 from any time 13 to 24.
Moon-phase: A window or complication on a watch face that shows the phases of the moon.
Mother-of-Pearl: Iridescent milky interior shell of the freshwater mollusk that is sliced thin and used on watch dials. While most have a milky white luster, mother-of-pearl also comes in other colors such as silvery gray, gray blue, pink and salmon predominantly used on pieces to give feminine feel.
Movement: The inner mechanism of watch that keeps time and moves the watch’s hand, calendar, etc. Movements are either mechanical or quartz.
Perpetual Calendar: A calendar that automatically adjusts for the months’ varying length and for leap years. Perpetual calendars, which are normally mechanical movements, are programmed to be accurate until the year 2100 with some very high end examples not needing changing for hundreds of years. Many watch collectors suggest storing in motorized winding boxes when they aren’t being worn in order to maintain the calendar countdown.
Platinum: One of the rarest of precious metals, platinum also is one of the strongest and heaviest, making it a popular choice for watches. It has a rich, white luster and an understated look. Platinum is hypoallergenic and tarnish resistant. Platinum used in watches is at least 85 to 95 percent pure. Many platinum watches are produced in limited editions due to the expense and rarity of the metal.
Power Reserve Indicator: A feature of a mechanical watch that shows the amount of energy reserve stored up to keep a watch running before it must be wound again or stops working.
Push-piece: Button that is pressed to work a mechanism. (the push-pieces on chronographs, striking watches, alarms, etc.)
Quartz Crystal: A tiny piece of synthetic quartz that oscillates at the rate of 32.768 times a second, dividing time into equal segments (See quartz movement).
Quartz Movement: A movement which allows a watch to keep time without being wound. This technology employs the vibrations of a tiny crystal to maintain timing accuracy. The power comes from a battery that must be replaced about every 1 or 2 years. In recent years, new quartz technology enables the watch to recharge itself without battery replacement. This power is generated via body motion similar to an automatic mechanical watch, or powered by light through a solar cell,. A digital quartz watch has no mechanical parts. Most quartz movements are made in Hong Kong, Japan or Switzerland.
Repeater: A device that chimes the time when the wearer pushes a button on either the quarter, half or the hour.
Rose (or pink) Gold: A softly hued gold that contains the same metals as yellow gold but with a higher concentration of copper in the alloy. A popular colour in Europe, rose gold in watches is often seen in retro styling or in tricolour gold versions. Some 18k red gold watches achieve their colour from additional copper in the alloy.
Rotating Bezel: A bezel (the ring surrounding the watch face) that can be turned. Different types of rotating bezels perform different timekeeping and mathematical functions.
Rotor: The part of an automatic watch that winds the movement’s main spring.
Sapphire Crystal: A crystal (the cover that protects the watch face) made of synthetic sapphire, a transparent shatter-resistant, scratch-resistant substance.
Screw-Lock Crown: A crown that can be screwed into the case to make the watch watertight.
Second Time-Zone Indicator: An additional dial that can be set to the time in another time zone. It lets the wearer keep track of local time and the time in another country simultaneously.
Shock Absorber: Resilient bearing which, in a watch, is intended to take up the shocks received by the balance staff and thus protects its delicate pivots from damage.
Skeleton Case: A case with a transparent front or back that allows the wearer to view the watch’s movement.
Slide Rule: A device, consisting of a logarithmic or other scale on the outer edge of the watch face that can be used to do mathematical calculations.
Solar Compass: A compass that lets the wearer determine the geographical poles by means of a rotating bezel. The wearer places the watch so that the hour hand faces the sun. He then takes half the distance between the position and 12 o’clock, and turns the bezel until its “south” marker is at that halfway point. Some quartz watches have solar compasses that show directions on an LCD display.
Solar Powered Batteries: Batteries in a quartz watch that are recharged via solar panels on the watch face.
Split Seconds Hand: Actually two hands, one a flyback hand the other a regular chronograph hand. When the wearer starts the chronograph, both hands move together. To time laps or different finishing times, the wearer can stop the flyback hand independently while the regular chronograph hand keeps moving, in effect “splitting” the hand(s) in two.
Stainless Steel: An extremely durable metal alloy (chromium is a main ingredient) that is virtually immune to rust, discolouration and corrosion; it can be highly polished, thus representing a precious metal due to this and the importance of white metal jewelry. Because of its strength, stainless steel is often used even on the casebacks of watches made of other metals.
Sterling Silver: A white and highly reflective precious metal. Sterling silver refers to silver that is 92.5 per cent pure, which should be stamped on the metal, sometimes accompanied by the initials of the designer or the country of origin as a hallmark. Although less durable than stainless steel and other precious metals, sterling silver is often employed in watches with a protective coating that is added to prevent tarnishing.
Stopwatch: A watch with a seconds hand that measures intervals of time. When a stopwatch is incorporated into a standard watch, both the stopwatch function and the timepiece are referred to as a “chronograph”.
Subdial: A small dial on the watch face used for any of several purposes, such as keeping track of elapsed minutes or hours on the chronograph or indicating the date.
Swiss Made: A watch is considered Swiss if its movement was assembled, started, adjusted and controlled by the manufacturer in Switzerland.
Swiss A.O.S.C. (Certificate of Origin): A mark identifying a watch that is assembled in Switzerland with components of Swiss origin.
All watches photographed courtesy of William & Son, 34-36 Bruton Street, London, W1J 6QX/ 020 7493 8385/ www.williamandson.com