Glossary

A barrier to the enjoyment of some luxury goods and services is a lack of familiarity with the terminology used by industry experts, manufacturers and journalists alike.

Sometimes we feel embarrassed to ask what is meant by a technical term, often French in origin, without fear of looking foolish or ignorant.

Our desire with this website is to improve the awareness of watch making at its best.  

We wish to describe some of the considered details which make haute horology something to be admired and encouraged.

Artisans who work on the finest wristwatches use tools at a bench for extended periods, endeavouring to deliver masterpieces made in precious metals which will provide their owner with faithful service and visual delight.


Watch Glossary Terms

Annual Calendar

A complicated watch which automatically makes allowance for the length of the month i.e. 30 or 31 days.

Balance Wheel

Used in mechanical watch movements.

Bevel

To bevel or “chamfer” involves removing sharp edges carefully using a lathe or file.

Bluing

To ensure improved corrosion resistance, hands are heated to a high temperature (approximately 300° C) to make them turn blue.

Bracelet

A term often used to describe a metal link watch band fitted with a clasp.

Bridge

A metal plate fastened to the base plate of the movement at two or more points to allow moving components to move beneath.

Calibre

This is a term often used to describe the movement within a watch.

Chronograph

A Chronograph not only shows the time of day but also includes a stop-watch facility for measuring a time interval and displaying it with a dedicated seconds hand, together with elapsed minutes and hours often shown on sub dials.

Chronometer

This term is used to describe a mechanical watch with a high level of accuracy.

Cock

The cock (or bar) is a metal plate which is attached to the base plate at one point, allowing room for a balance wheel to be located underneath.

Crown

The crown is used to wind the mainspring as well as adjust the time displayed on the watch.

Deployant

This is a term given to a clasp on a watch strap which provides a more complex and expensive alternative to the pin-buckle.

Enamelling

A glass-like substance that is used in the form of coloured enamel powders which are mixed with special oils and applied like paint.

Engraving

The art of engraving is employed in haute horology to adorn the case and the movement using burins (a special chisel type tool).

Escapement

The Escape Wheel, Pallet Fork, Balance Spring and Balance wheel form the Escapement which controls the energy from the Spring Barrel and converts it into accurate, portions of energy to ensure that the gear train runs smoothly and accurately.

Finissage

Finissage or “Finishing” is the term given to time-consuming bevelling, guilloché, engraving, anglage, perlage, and polishing associated with fine watchmaking.

Gear Train

The Gear Train transfers power from the Mainspring to the balance wheel.

Geneva Stripes

Geneva Stripes sometimes called “Côtes de Genève”.

Glashütte Ribbing

A variation of “Geneva Stripes” found on movements from Glashütte watchmakers.

GMT

GMT is a term used to describe a watch which carries an additional hour hand that can be adjusted by the wearer to indicate the hours in another time zone.

Gold Chatons

Originally a plate would have been drilled to accommodate rubies to reduce friction.

Pushing a ruby into the drilled hole would be simple but may have resulted in the jewel becoming damaged.

Guilloché

Guilloché is a traditional surface decoration applied to the dial or rotor (on automatic movements), created using a grooving tool with a sharp tip to create an even pattern on the surface.

Helium Valve

When diving at great depths, divers will acclimatise within a diving bell to increase their tolerance to the pressures at the working depth.

Index Adjuster

The steel spring on the movement shown is pressed against the tip of a small screw. By turning this screw in or out, the rate of the movement can be adjusted.

Jewel

The friction of the rotating gear wheels within a traditional pocket watch movement was often reduced by using rubies lubricated with a very thin layer of special oil.

Minute Repeater

A complication using hammers and gongs to deliver chimes to signify hours, quarter hours and minutes.

Perlage

Surface decoration featuring overlapping circles created with a rapidly rotating wooden peg.

Perpetual Calendar

A Perpetual Calendar typically displays date, month, year and sometimes moon phase too.

Pin Buckle

The pin buckle sometimes called a tang buckle is fitted to a strap and provides a cheaper alternative to a deployant.

Power Reserve Indicator

The indicator shows the amount of power held within the mainspring expressed in terms of days.

Rattrapante

A French word used to describe a split seconds chronograph.

Unlike a standard chronograph, the split seconds chronograph has two hands that start simultaneously.

Rotor

The rotor is an eccentric weight found in automatic watches, often semi-circular in appearance which turns on a pivot and winds the mainspring when the wearer’s wrist moves.

Sandwich Dial

Panerai offer some models featuring a sandwich dial which involves a dial consisting of numbers and indices cut out to reveal a second luminous dial beneath.

Sapphire Crystal

Synthetic sapphire crystal is made from Aluminium Oxide into a clear colourless, fully transparent material.

Screw Balance

A screwed balance contains small weighted screws which can be adjusted to achieve the desired inertia.

Spring barrel

The spring barrel contains the mainspring which stores the energy to drive the gear train.

Three-quarter plate

Typical of A. Lange & Söhne, an untreated silver plate is drilled and simultaneously positioned onto several arbors.

Tourbillon

Tourbillon means “whirlwind” and is regarded as the ultimate watch complication.

Vibrations per hour (vph)

The balance wheel oscillates anti-clock wise and clock-wise through a range of two extreme positions (typically about 300 degrees apart).