Glossary F-M

FEET	commonly used to measure water resistance.
FINE TIME ADJUSTMENT	lever to adjust the daily time accurately.
FIVE-MINUTE REPEATER	a function that strikes the hours and five-minute intervals past the hour.
FLANGE	ring that separates the crystal from the dial.
FLYBACK	function that allows a chronograph to be reset to zero without having to stop the chronograph first.
FOUDROYANTE	small dial that is marked 0-8. The hand on the dial completes a sweep every second which is an elapsed time of 1/8th of second for each number.
FREQUENCY	number of vibrations a second or oscillations per second, in hertz (Hz) of a quartz watch. The number of vibrations per hour (VpH) of a mechanical watch.
FULL ROTOR	automatic watches with rotors that travel 360 degrees in both directions.
FUNCTION	the same as a complication on a mechanical watch, but technically called a function on a quartz watch.
FUSEE	grooved pulley that equalizes the mainspring by controlling its winding or unwinding.
GASKET	most water resistant watches are equipped with gaskets to seal the caseback, crystal, and crown from water. Gaskets need to be checked every couple of years to maintain water resistance.
GENEVA SEAL	quality seal the displays the City of Geneva coat of arms. Watches must meet eleven strict criteria to be awarded the Geneva seal.
GLUCYDUR	copper and glucinum stainless, non-magnetic alloy used in watch making for internal parts. Anit-magnetic alloy that expands very little when exposed to heat. (Used for balances)
GMT	Greenwich Mean Time, marking the middle of a solar day, is the time measured from zero degrees latitude in Greenwich, England. It is the standard for time keeping introduced in England in 1880 and used as the basis for calculating standard time throughout the world. It reflects the mean solar time along the Earth’s prime meridian. (0 degrees longitude). The prime meridian runs through the Greenwich Observatory outside of London.
GOING TRAIN	made up of the going barrel, which drive the center wheel. The center wheel drives the third wheel then the 3rd wheel drives the second wheel. The second wheel drives the escapement wheel. It is the system of gears that transmits power from the mainspring to the escapement.
GUILLOCHE	decoration found on the dials of high-end watches.
HACKING	a feature that stops the second hand when the stem is pulled out as far as it will go and allows you to set the exact time.
HAIRSPRING	same as balance spring.
HALLMARK	a mark stamped into the case of the watch to provide information about the degree of purity of the metal used, the country of origin, the country of origin, the year of manufacture, the identity of the case’s maker, trademarks, reference numbers, and/or serial numbers.
HAND	watches generally have three hands for seconds, minutes, and hours. They come in many different shapes: Pear, Breguet, Baton, Arrow, Skeleton, Luminous, Alpha, Dauphine, etc.
HAND-WOUND WATCH	a watch that receives energy by hand winding the crown.
HARDBACK	caseback made of metal.
HARD METAL	scratch resistant metal comprised of binding several materials, including titanium and tungsten which are then pressed into an extremely hard metal and polished with diamond powder to add brilliance.
HELIUM ESCAPE VALVE	a helium escape valve is required for divers who spend a long time in hyperbaric chambers and breath helium enriched gas. The helium molecules are lighter than air and can therefore penetrate the watch. When a pressurized enclosure, such as a diving bell, surfaces and is depressurized the helium rushes out of the watch so quickly that the crystal on the watch pops out. To avoid this the helium escape valve releases this helium from the watch while resurfacing. This allows helium to escape without water entering the watch.
HESALITE	brand name acrylic crystal. Omega chose “Hesalite” for the crystal on their moon watch because of its resistance to shocks and extreme temperatures.
HIGH-TECH CERAMIC	used as a shield for spacecraft reentering the earth’s atmosphere, high tech ceramic is polished with diamond dust to create a highly polished finish. Usually found in black.
HORNS	part of the case where the bracelet is attached by lugs or pins.
HOROLOGY	science of time measurement, including the art of designing and constructing timepieces.
INCABLOC	a brand of shock absorber for mechanical watches designed to protect pinions or jewels.
INDEX	instead of a number, a marking indicating the hour and/or minutes.
INTERNAL BEZEL	a bezel inside the watch case usually with a separate or additional crown.
INVAR	special alloy related to beryllium and used for watch parts because it is anti-magnetic and resists rust.
ISOCHRONISM	equal periods of time. A watch’s ability to maintain it’s rate as the mainspring unwinds.
JEWELS	synthetic sapphires or rubies that are used in a watch movement to reduce friction. They help maintain the watch’s lubrication.
JULIAN CALENDAR	Julius Caesar introduced a calendar with 12 months and 365 days. Previously the calendar had 10 months of 30 days each. The Julian calendar introduced “leap year” stating that a day would be added to the calendar every 4 years. That is required because there are roughly 365.25 days in a year.
JUMP HOUR	a spring that causes a hand or other part of a watch to suddenly advance. A jump hour watch displays the hour through a dial window.
KIF	method of shock protection.
KINETIC	quartz movement that does not use a battery. Energy is stored for a period of time though movement of the wrist that charges a capacitor. (Seiko Kinetic)
LAP TIMER	a chronograph function that times segments of a race. At the end of a lap a push button stops the time and then returns to zero to time the next lap.
LCD	liquid crystal display.
LEAP YEAR	an extra day every 6 years Feb 29.
LED	light emitting diode.
LEVER ESCAPEMENT	18th century invention which is made up of an escape wheel, a lever, and a balance wheel, the only one now used in making mechanical watches.
LIGHTED DIALS	several types of lighted dials are used to read your watch in low light conditions.
LIGNE	traditional unit of measurement used to measure the diameter of watch movements.
LUG	(same as horn) part of case where bracelet or strap is attached.
LUMINOUS PAINT	self-illuminating paint that is put on the hands and markers to read the time in low light situations.
MAIN PLATE	the base plate on which all other parts of a watch movement are mounted.
MAIN SPRING	the driving flat-coiled spring of a watch contained in the barrel, supplies power.
MANUAL-WINDING	a hand wound mechanical watch
MANUFACTURE	factory that makes its’ own components and assembles at least one complete movement (caliber). A manufacture produces the movement and then assembles it.
MARINE CHRONOMETER	a highly accurate timepiece enclosed in a box that is used for determining the longitude on board a ship. A marine chronometer is mounted on gimbals so that they remain in a horizontal position to maintain their precision.
MECHANICAL	describes a movement with a balance wheel. Wound by hand or rotor. Dates back to the 14th century about 130 parts plus 60 for complications.
METER	a measurement used to measure water resistance. (10m= 33.3ft= 1ATM= 1BAR)
MICRON	1/1000mm (.001 millimetre)
MICRO ROTOR	small rotor that is integrated into the movement and used on automatic watches. It allows the construction of very thin calibers.
MINERAL GLASS	glass that has been tempered to resist scratching.
MINUTE REPEATER	a function on a watch that can strike the time in hours, quarters, or seconds by means of a push piece.
MOON PHASE	shows: new moon, first quarter moon, full moon, and last quarter moon by means of a disk that rotates beneath a small aperture. The 29 and 1/2 day cycle of the moon.
MOVEMENT	the “motor” of a watch or the machinery that turn the hands, change the date, start/stop the chronograph. There are two classifications of movement, either mechanical or quartz electronic.