Watches TAG Heuer Watchlover’s ‘University’: An Entertaining Encyclopedia of Watchspeak


8 min

The definition of every weird and wonderful watch term in our vocabulary – in a series of watch anatomy lessons to answer your burning FAQs. From Apertures to Zero-setting, it’s time to get your Watch Terminology officially in order.

If you’ve ever been afraid to ask anything about watches for fear of exposing ignorance, you’ve come to the right place.  When your friends compare notes on their tourbillons, no longer will you stare blankly into space and wonder whether they’re discussing a new French cheese or something to do with V8 engines.  Now is the moment to bite the bullet and explore our encyclopaedia of watchmaking FAQ’s and terminology – for everyone from the complete novice all the way to some niche terms for the seasoned collector. As the saying goes ‘anyone who keeps learning stays young’ – so put away that ab stimulator and exercise your grey matter instead. Soon, you’ll be dropping choice gems about Jewels and some bold zingers about Bezels into everyday conversation like a native in the land of Horology. Welcome to the only phrasebook for Watchspeak you’ll ever need.  

Since its invention in the early 16th Century, the mechanical watch has been sought-after and admired for the exquisite craftsmanship of its delicate internal movement. In this guide we’ll explore the watch movement itself – what it is, what it does, useful terms – and answer some of the questions common amongst newly-minted watch enthusiasts….  before introducing you to TAG Heuer’s in-house Calibre Heuer 02 movement.

So, what is a movement?

The watch movement, also called the ‘calibre’, is the beating heart of every timepiece. This elegant internal mechanism powers all of the watches functions, from the movement of the hands to the chronograph, alarms, calendars, and any other complications. A mechanical movement is made up of an intricate series of springs and gears that turn energy into precisely regulated movements. This allows the watch to run with exceptional efficiency, and accurately keep track of the passage of time. Forget the beautiful platinum case, that personalised face, or your vintage alligator strap. This is the real ‘heart’ of a watch, usually hidden behind the scenes (some watches have clear case backs or faces to make the movement visible); 

But to most horologists – and many a watch-lover – the movement is far more than just the ‘engine’ of a watch. Crafted with expert savoir-faire acquired over hundreds of years, a well-made timepiece is a thing of great beauty – with a degree of elegance in its engineering that brings it closer to a work of art.

Are there different types of Movement?

Short answer is yes – three.  Automatic, Manual, and Quartz.  A quartz watch is powered by a battery or solar cell, in which the timekeeping is regulated by a quartz crystal that vibrates at a certain frequency. But we’ll focus here on the two more complex types used in luxury watchmaking: Automatic and Manual.


A manual watch movement requires the wearer to manually wind the watch, usually once a day, in order for it to work. It’s the oldest and most traditional type of watch movement, and is beloved by many collectors for the expert craftsmanship involved. Both manual and Automatic watches will often have a transparent case-back, to show off the intricate beauty of the movement inside.

A manual movement also uses kinetic energy, instead of a battery, to power the timepiece. Turning the crown produces energy, which is then transferred into the spring. Here, this energy is stored as the spring gets tighter, and it is then released through a series of gears and springs to power the watch’s functions and complications.


An automatic watch movement is similar to a manual watch, but with a few important differences. An automatic timepiece winds itself whilst worn, by making use of kinetic energy. Provided the watch is worn regularly, it will maintain its power without any need for manual winding by the wearer. The TAG Heuer calibre Heuer 02, for example, has an impressive 80 hour power reserve, after which it will need to be worn or moved to wind.  Automatic watches are also often thicker and heavier than their manual counterparts, due to the extra components needed to function.

An automatic movement is wound by the action of the wearer’s wrist. An oscillating weight (or rotor) pivots freely around a spindle, and each movement helps to wind the spring (the watch’s energy source), charging the power reserve. The regulator of the watch is a balance wheel with a swing that vibrates, on average, 4 times a second. 

Each automatic movement comprises over 70 parts, and the smallest of these is no thicker than a human hair (0.07mm). All of these mechanical components work continually in unison, creating the effect of a sweeping second hand instead of the jerky movement of a quartz watch. While it is less precise than a quartz movement (by a few minutes per month), an automatic movement is the ultimate example of Swiss watchmaking expertise and tradition.

So… what’s that Power Reserve thing you mentioned?

The power reserve is the amount of power a watch accumulates in order to keep the timepiece or chronograph functioning without being wound. The TAG Heuer automatic movements have long power reserves – such as the Heuer Calibre 02, at 80 hours and the Heuer 02T, at 64 hours. But it’s still important to keep moving! Because the action of the wearer’s wrist is what winds up the movement and maintains maximum power, the power reserve will begin to drain if there isn’t enough actual, physical movement – causing the watch to stop. You can recharge it by turning the crown clockwise, giving it sufficient power reserve to function normally. But it’s more fun just to take your beloved watch out for a spin regularly – and make sure to use some hand gestures over dinner. 

What are the terms I should know to discuss my watch Movement?

  • Crown: The wearer turns the wheel at the side of the watch to wind it and set it on time.


  • Spring: The kinetic energy generated by turning the crown is transferred and stored in the coil-shaped mainspring. The tighter the spring gets, the more energy is stored, and the longer the watch can be powered for.


  • Gear train: As the spring slowly unwinds, the stored energy is released through the intricate series of gears in the gear train, and into the escapement.


  • Escapement: The escapement controls the release of energy, ensuring it is metered out in precise increments. The distinctive ticking sound a watch makes is the escapement and each sound represents a transmission of energy to the balance wheel.


  • Balance wheel: The balance wheel is the heart of a watch, and allows the movement to regulate time. The oscillations, or beats, of the balance wheel require skillful adjustment in order for the watch to run accurately.


  • Display gear: The display gears transmit the precisely regulated rotation from the balance wheel to the watch hands. This causes the hands to move at the right intervals to keep the time.