The diver’s watch is one of the most celebrated trends in horology

We cannot deny that Diver’s watches are among the most sought-after kinds of timepieces – and the most iconic watch there is has a revealing name: Rolex Submariner.

But apart from this, there is a big confusion over what a diver’s watch truly is, and more, about what does the water resistance shown on the dials and backs of watches truly represent. So we want to shed a bit of light over the matter in order to understand better the key differences that render a true diver’s watch much different from a water-resistant watch.

Ask yourself what a “dive watch” really is!

There is an important difference from a water-resistant watch and a diver’s watch, as every watch has a water resistance.

It is part of the game, that is. Even a dress watch has some sort of minimal water resistance – which usually lies in the range of 3 bar (around 30 meters). This means that saying that a watch has a “water resistance” is not enough – as water resistance alone does not make a diver watch. And if we search a little bit more, we find out that for a watch to be called a diver’s watch, a timepiece has to comply with a very specific set of parameters which are stated in an ISO certification: ISO 6425, to be specific.

The minimum requirements for mechanical diver’s watches (quartz and digital watches have slightly differing readability requirements) are the following (per wikipedia):

  1. Equipped with a diving time indicator (e.g. rotating bezel, digital display, or other). This device shall allow the reading of the diving time with a resolution of 1 min or better over at least 60 min.
  2. The presence of clearly distinguishable minute markings on the watch face.
  3. Adequate readability/visibility at 25 cm (9.8 in) in total darkness.
  4. The presence of an indication that the watch is running in total darkness. This is usually indicated by a running second hand with a luminous tip or tail.
  5. Magnetic resistance. This is tested by 3 exposures to a direct current magnetic field of 4,800 A/m. The watch must keep its accuracy to ± 30 seconds/day as measured before the test despite the magnetic field.
  6. Shock resistance. This is tested by two shocks (one on the 9 o’clock side, and one to the crystal and perpendicular to the face). The shock is usually delivered by a hard plastic hammer mounted as a pendulum, so as to deliver a measured amount of energy, specifically, a 3 kg hammer with an impact velocity of 4.43 m/s. The change in rate allowed is ± 60 seconds/day.
  7. Chemical resistance. This is tested by immersion in a 30 g/l NaCl solution for 24 hours to test its rust resistance. This test water solution has a salinity comparable to normal seawater.
  8. Strap/band solidity. This is tested by applying a force of 200 N (45 lbf) to each spring bar (or attaching point) in opposite directions with no damage to the watch or attachment point.
  9. The presence of an End Of Life (EOL) indicator on battery powered watches.

Please note that there is no water resistance minimum stated: however, since the whole affair of diver’s watches started with the production of the first Submariner and Fifty Fathoms, the minimum viable water-resistance for a diver’s watch is assumed to be 100 meters (10 bar). These watches are the oldest: current diver’s start with a 20 bar (200 meters) water-resistance.

Who’s ensuring these characteristics are respected?

Everyone can make watches  that comply with these specs, but “official” divers are similar to “chronometers”: to be officially called like this, they need to be certified by an external, independent organization.

So, in the case of ISO-compliant watches, these tests have to be administered by an officially-certified laboratory – and have a cost of issue.

This means that companies cannot simply state they make a diver’s watch: they should have a proof of it to be so. It also means that not every manufacturer present their watches for certification according to this standard, so they just state that they are compliant and that’s enough. However, they cannot use the official denomination of “Diver’s watch” – which is usually displayed on the dial, when present.

But this first difference takes us to the real meaning of the number that we see on the dial – that is, water resistance.

One of the main issues about water resistance is understanding what it indicates. People routinely buy 30-meter water-resistant watches and then splash into a pool, with water getting into them – and getting the watch-wearers undoubtedly puzzled, to say the least.

Divers watches and water-resistance

The levels of water resistance that we see indicated in a watch measure the maximum depth that a watch can attain in static conditions. It means lowering them gradually – like through a wire – until they reach the mentioned depth. In the case described above, it would be 30 meters.

But what happens if you dive into a pool? That the watch has to sustain a sudden change of pressure that would probably exceed the stated water resistance.

Just the act of someone swimming in a pool freestyle produces a pressure on the watch of around 5 bar.

But your very own house is not secure at all. To make an example of routine real-life situations, the water faucet system of your house has a typical water pressure of 3 bar – that is, the typical pressure of around 30 meters depth. A shower would exceed that a bit – ordinarily, it is about 50 psi (pounds per square inch) – approximately 3.5 bar. Diving into a pool would subjects your watch to a pressure of at least 5 bar if not more: not something that your typical 30-meter water-resistant watch is going to withstand without consequences.

This is the reason why watchmaking companies accompany their watches with handy tables so you can check the activities you can perform while wearing your watch. Too bad that most of the time, people ignore them and instead rely on what is written on the dial, exclusively – and must have a quick consult with their watchmaker afterward.

You can find much more about horology and its fascinating history in The Watch Manual. It is a thorough e-book that explains all the basics about watchmaking and its protagonists.

To download a FREE 8-chapter extract from The Watch Manual

Chinese watch quality? From lousy to great

We are not the first commenting about that, but Chinese watch quality is always a big interrogation mark hanging in the air. And while you can get excellent timepieces, if you examine the products from the most advanced companies, you cannot say the same for the majority of the production of the Land of the Dragon.

The main issue is that statistically, the majority of horological products coming from China are of medium-low quality, mainly belonging to the “fashion” category.

Fast fashion and horology

While not strictly belonging to the fashion planet, the evolution of the typical watch has  taken it to be perceived as an ornament. Thus, it has fallen into the overall personal style, especially since its primary function – being a timepiece – has become somewhat secondary.
So, going back to fashion, around the end of the Seventies the fashion industry invented a business model called “fast fashion“.

In short, fast fashion is an extremization of the pret-a-porter: it is a model which sells trendy clothes of low quality, engineered to have a very short lifespan, like one season only.

After they have absolved its function, fast fashion clothes are eventually discarded. The typical fast fashion retail chains are Zara, H+M, C&A, Uniqlo and similar companies. As you can readily see, it is a hardly sustainable and little eco-conscious model.

The watch industry has adopted it by adapting the franchising model to it. Important brands license their asset – the brand – to be applied to objects of little quality, so to provide their customers and would-be customers an “easy entry” into the brand experience.

For example, even if you cannot afford to buy an Armani suit, you can afford to buy an Armani watch. You would get an official Armani-sanctioned object to appease your taste for everything Armani.

Specialized companies have extended the fast fashion business model

A few big groups – most of them US-based – have applied this business model into their strategy: so they have become both editors of licensed brands and original manufacturers. A few of them have bought the rights to use old horology brands, such as Ingersoll, and have released collections of trendy timepieces which are sourced using their existing business connections. That is, Chinese manufacturers.

The main feature of these productions is that they are extremely cheap. Because fast fashion products are expected to be cheap – they are not meant to last. So, even the watches which do not belong to a fashion brand are – in a away or another – mostly subject to this spillover effect. Obviously, the products are not of the same quality: there are several lines of different prices and of different makes.

To make an example, the Fossil group makes watches marked under different brands. Some belong to fashion brands, others are marked Fossil. And between the latter, there is a line of mechanical watches which are made in Switzerland and mount mechanical movements manufactured by STP, a Swiss subsidiary of the Fossil group. These latter represent the top end of the Fossil production, and cost accordingly. But a “basic” Fossil watch is made in China, and mounts Chinese-made quartz movements.

Most companies have embraced this business model

As the fast fashion business model is highly profitable, most companies have adopted it. So, most of the Kickstarter brands that you see around depend on it. And as we have stated, it is a completely predatory model made for producing endless junk – which is not what out planet is needing.

This takes us to the manufacturers (which are different from the originators) of it: China.

So, are Chinese watches bad? Not at all.

This is not a profession of watch snobbery. The issue is that Chinese production is not even – some is crappy, and some is excellent. This is the real issue for a Westerner you are never really sure of what you will get at the end. So, some of the best Chinese productions are on the par of Swiss-made watches, while other products are definitively lacking in quality and finishings, because they are not made to last. The issue is that we deal with a stereotype: that Chinese-made watches are of low quality. And this is ultimately not true.

Chinese watches, the beginning of a new phase

If we examine Chinese-made watches, we tend to compare them with other Eastern timepieces.And the paragon today is not favorable.

For example, watches coming from a Japanese manufacturer have overcome the stigma from their initial low-end positioning. All that you would get from companies such as Seiko or Orient today would be perfect – except for the proverbial lemon, but this would be very rare. From a company like the modern Ingersoll, you could get a great timepiece which would work for many years. Or not, if you are less lucky.

Celadon watches – “Made in China with pride”

We should always remember that Seiko and Orient watches from 60 years ago were much less valued – and technically refined – than what they are today. The “Made in Japan” of the Sixties was on the par of the “Made in China” of today. So, Chinese watch quality is bound to increase, in time – but more, the perception of it is going to become greater. We see the first effects already in the latest Chinese production. They will grow, no doubt.

You can find much more about horology and its fascinating history in The Watch Manual. It is a thorough e-book that explains all the basics about watchmaking and its protagonists.

To download a FREE 8-chapter extract from The Watch Manual

The watch precision has developed tremendously in time

Since the establishment of fixed hours, clockmakers have strived to render the watches as precise as they could, through different, ingenious devices.

The Salisbury Cathedral Clock, circa 1385

We know from experience that tests conducted on the oldest surviving mechanical clock in the world, the faceless clock of the Cathedral of Salisbury, dating approximately to 1385, have discovered that the watch precision that this timepiece obtained was remarkable, within two minutes per day.

Such a performance – which was indeed very good for the time – would be replicated by watches only much later, and thanks to lots of development by figures like Galileo and Huygens.

Indeed, around 1650, another scientist called Robert Hooke theorized something that would be important for watchmaking: the theory of harmonic oscillations, which would be important for two key elements of the watch: the mainspring and the balance wheel. And as both of them use a spring in their operation, the smartest of my readers have understood about what we are talking about.

Read also Why Rafael Nadal’s watch is so expensive?

The application of Hooke’s Law

In short, a spring impart to a weight suspended on them a movement that is “harmonic” – it follows a constant sinusoidal oscillation path, if released.

In the ideal condition of no attrition, it would continue to oscillate like this forever.

But even if it doesn’t, if we continue to apply constant force to it making it move in such a way, the oscillation will continue regularly.

And this is the main principle we apply to watches.

The regulatory device of a watch works like this. That is, it is based around a harmonic oscillator of some kind.

The first harmonic oscillators used in watches were the balance springs. They are the tiny spiralling springs that lie on top of balance wheels and make them oscillate back and forth following a harmonic oscillation.

The increase in watch precision: electromechanical watches

In the quest for better precision, watchmakers discovered that a tuning fork emits  a fixed vibration that is based on harmonic oscillation as well. The diapason was miniaturized and used as a regulating device in watches such as the Bulova Accutron.

Bulova Accutron Spaceview. Tuning fork on the center/top.

The evolutions of electromechanical watches – which debuted in the 1960s – have brought us the quartz-based system, which works on a different system based on a similar concept.

The oscillator in a quartz watch

In a quartz-based watch – the first one was the Seiko Astron, which was launched in 1970, we find an oscillator composed by a quartz crystal that is cut in a small tuning fork shape on a particular crystal plane.

When subject to a current, this crystals vibrates at a specific frequency – which is subject to the electrical current applied to it. This frequency was originally 32,768 Hz (some of the latest quartz movements vibrate at higher frequencies). insuring a very high watch precision.

Today, we are exploring other solutions to create a harmonic oscillator. The next frontier in this research will be the use of silicon elements. Several promising calibers have been manufactured, like the Zenith Defy. However, the industry is still using either mechanical-based regulating elements based on balance wheels or quartz-based systems (and their evolutions like the Seiko Kinetic and the Seiko Spring Drive.

A swan-neck regulator on this mechanical watch movement

How do you regulate these systems?

Obviously, when a watch comes out the factory it is not precise at all. It must be regulated to achieve a good precision. And watchmakers have developed ways to regulate the different movements so they perform at the best of their possibility.

The mechanical watches use an ingenious regulator placed obeve the balance wheel bridge (known as a balance wheel cock) – it is a regulator that can be turned to adjust the dimension of the hairspring. Diffenet dimensions would lend the balance wheel to beat slower or quicker.

While the regular watches had a lever, more precise ones have micrometric adjustments regulated by a screw. Some modern watches use different systems to regulate, such as counterweights placed on the balance wheel itself.

In a quartz-based watch, regulation is not possible. That is, it is already built in.

You can see this black blob under the orange arrow? It covers a small microchip which controls the operations of the quartz movement. This means that the quartz resonator (the grey cylinder you see on the left) has a built in correction that intervenes if it feels that the vibration rate of the watch is out of the range.
In the first quartz movements, watchmakers could intervene to regulate the watch through a tiny screw, but as time passed, the circuits were streamlined and simplified, and the microchip was inserted to resolve the issue from the beginning.

You can find much more about horology and its fascinating history in The Watch Manual. It is a thorough e-book that explains all the basics about watchmaking and its protagonists.

To download a FREE 8-chapter extract from The Watch Manual

How was the crown invented? What does it hide?

The watch crown, which is a common sight nowadays, is a somewhat recent addition to the watches arsenal. Prior to its invention in 1842, watches used a key, as most clocks already did: after all, watches are just small, portable clocks.

To wind them or regulate them, you inserted the key (which came in different sizes) in a slot, and you could recharge the watch by turning the mainspring, or regulate the hands.

On the image on the left you can see the two slots used to this end. You might also note two keys, on the right of the image, as most probably this particular watch had been serviced in the past and one of the elements changed, needing the watchmaker to add one key to the set.

You might understand that this solution was not exactly ideal: to properly use a watch, you would have had to carry it around, as well as its key – which would possibly scratch the case.

So, companies started to tinker with this concept in order to supply a watch that would not need any keys to wind up or regulate.

So, in a word, which used a “keyless” system. And eventually, a watchmaker managed to invent the first system, which was perfected in time to become the one we are using now.

His name was Jean Adrien Philippe. And yes – it was THAT Philippe – one of the founders of Patek Philippe.

Jean Adrien Philippe

The inventor of the keyless works

Jean Adrien Philippe was a French horologist, who worked to perfect the keyless works system. His solution – which is very similar to the one that we still use today – relied ona mechanism that could operate two different sets of wheels to perform either functions of the watch – namely, winding it and regulating it.

He patented his invention in 1842 and presented it at the French Industrial Exposition (World’s Fair) of Paris in 1844, and winning a Gold Medal. In this same occasion, he met Antoni Patek, and the two started to cooperate.

The relation went so well that in 1851 Philippe entered into Patek & Cie as a full partner, with the company renamed Patek Philippe.

Coming back to our keyless works, they were improved by another watchmaking legend, Charles-Antoine LeCoultre in 1847, with the invention of the sliding stem activating a small lever to activate the second function, which he called “remontoir à bascule“.

Coming back to Philippe , he created the first concept of the crown. The crown was connected to the keyless works through a stem, and the whole assembly was protected by the ring that was used to link the watch to its chain. The naming of this element came almost naturally, as the crown was normally placed on top of the watch, at twelve o’clock, and its shape and design indeed reminded people of one.

A beautiful Patek Philippe pocket watch

The evolution of the crown

The standardization of calibers and the development of etablissage brought the companies towards the creation of “standard” sizes of stems, and so, crowns. In time, stems started to have a screw end, which went into the crown. This is the system that we mostly use today in common watches.

However, let’s check the typical watch crowns that you might encounter when examining a typical watch.

As you can see, we have many. Some are simple, and others instead are quite complex, offering a sort of recess where they meet another part of the watch case: a tube that gets out of the main case, in order to secure a better  water resistance to the watch.

If we take a look at diver watches, instead, we see that it is rather common to see crowns screwed to the tube so to offer better resistance to water. This is why every watch – and every case – is different, and so the crown must be fitted case-by-case to ensure that it makes a perfect fit to the overall style of the watch.

A screw-on tube on a diver watch

The screw-on crowns and diver watches

The need to ensure a more secure resistance to water prompted the watch companies to create screw-on crowns. As you can see on the image, screw-on crowns connect through a screw-like system on the tube that that is fitted on the watch case.
This system, which is also fitted with different rubber/silicone gaskets, ensures that the crown completely insulates the watch from water when submerged.
Of course, it is impossible to operate the crown of the watch when it is closed: it is impossible to wind the watch or regulate the hours. This is the main reason why diver watches always use automatic movements. This was the solution that Rolex adopted when it launched its first Rolex Perpetual movement in 1931, and other companies followed.

Crowns and personalization: do I need the original crown?

A Seiko watch crown + stem with the logo

Today, many famous brands personalize the crowns with their brand logo.

This means that, if you somehow lose yours (stems are a rather delicate element, and only the pressure of a small screw secures them to the movement), you are going to pay a sizable sum to find an original crown.
While finding one ensures the originality of your watch, in the case when you do not care about it, your watchmaker could always fit a “generic” crown (without logo) to your watch without issues.
However, please take note that, historically spealing, this “branding fad” is quite recent, starting in the mid-Fifties, as in the beginning of the last century, few crowns displayed an impressed logo (most did not). So, if you see a shiny crown with a logo on an older watch, beware: it might just be a later add-on.

You can find much more about horology and its fascinating history in The Watch Manual, a thorough e-book that explains all the basics about watchmaking and its protagonists.

To download a FREE 8-chapter extract from The Watch Manual

Why is it so hard to take off the back of a watch?

The answer is to keep the movement away from casual people tinkering with it.

And I mean YOU.

A mechanical watch is a sort of carefully balanced little mechanism which can be swayed by the presence of a minuscole blog of dirt. It runs on tiny pivots that would make an average needle look like a hulking behemoth.

And you really want that someone would open it to examine and touch this assembly with his fumbly and greasy fingers? No way, sir.

A bridge with the fingerprint of a careless user on it

Yes, what you can see here is the longterm effect on a bridge of ONE careless fingerprint left on its surface.

This is the main reason why watch backs are difficult to pry open.

The need of protecting the service network

Even if you – the end user – possess the technical skills neeeded to perform some routinary operations on a watch, the watchmaking company instead makes its best to restrict you from doing it.

And the reason why is simple.

While in the past it was pretty normal that any watchmakerrepaired watches, in more recent times companies try to give this privilege only to their official authorized  assistance network of technical service centers.

The back of a Rolex Oyster case

As you know, the markup on the object itself is not the main objective: the real deal is performing the routine assistance. And this is what the watch companies are pushing their retailers to do.

One of the easiest ways to do this is to create a closure that can be opened with a special tool only, which is not widely available. This is the case of the Rolex Oystercase, that needs a special die to clutch the indentations at the base of the back and let them rotate to unscrew the back from the case.

Rolex is not the only culprit doing this: Breitling and Longines have done it as well. This means that if you do not have that special key, you cannot open the back. But professional watchmakers do have the necessary keys to open different kinds of watches.

As you can clearly see, the back of an Oystercase is not easy to accesss. You need a proper tool to do that without scratching the surfaces.

A screw-on back on a Girard Perregaux watch

The need to close the back safely

The last thought is that watchmakers had to develop a closing system that was both good enough to perform its duty, and cheap enough to be installed in an industrial production.

One of the main enemies of watches, before water, was dust. If dust went into a watch, it would impair its operation, and clog the oil used inside to lubricate its movement. So, companies had to find ways to keep the dust out of watches. And when the fad of water came, the experience they had was applied towards it.

This need brought companies into the manufacturing of the two main closure systems that you’d find: snap-on and screw-on.

Snap-on systems are the cheapest. They are composed by a lid that snaps on and off the case if you use enough pressure and skill. To facilitate this happening, they generally have an indent or a sort of nail where you can place an case opener tool , press and twist a bit. If you have done it carefully, the back would snap off without you scratching the watch (yes, this is the main issue – you definitely CAN scratch it deeply if you are not careful and accustomed to it).

The small indent of a snap-on watch back

Screw-on systems are generally more costly. They are composed by a back that is screwn on the case by using a special wrench. The backs have generally a few indents – normally six – where you can place the points of a special wrench, press hard and twist it so to unscrew the back. In the case of the Girard Perregaux above, there are eight – so you’d need a special key.

A screw-on back is much more water resistant than a snap-on one, as you would suppose, and many of them are protected by a rubber or silicone gasket to further insulate the mechanism from the water.

An assortment of silicone gaskets

Beware of the gaskets

Remember that when you remove a watch back, in many instances you will find a silicone gasket which has been put there to protect the mechanism from water and dust getting in and rusting or clogging the delicate wheels of the movement.

A silicone gasket has a limited duration, generally five years – and must be periodically lubrified to keep int in good shape. If you do not, the water resistance of your watch is at risk, and water and dust could get in, with possibly dire consequences.

As said before, do not open a watch back if you do not know what to do, because you would probably damage its mechanism.

Another advice is that while Quartz watches are way sturdier than mechanical watches, so they survive much rougher handling as well. this means that their backs are generally easier to open, especially since you need to change the battery every now and then.

But mechanical watches make their best to deter you from opening them, and with very good reasons.

You can find much more about horology and its fascinating history in The Watch Manual, a thorough e-book that explains all the basics about watchmaking and its protagonists.

To download a FREE 8-chapter extract from The Watch Manual

Why don’t we see many silver watch cases?

Precious metals like silver and gold were extremely popular throughout human history as a preferred material to make precious objects. Still, nowadays silver is seldom – if ever – used in the manufacture of watches.

The motivation for this lack of popularity depends on a phenomenon that happens with allthe silverware you come across – which regards also silver ornaments like jewelry.


When worn in contact to the skin, silver has the tendency of staining  the skin and the clothes with a darkish mark. This was not an issue back in time, when people used to wear pocket watches, but when pocket watches migrated to the wrist, the effect of silver smudging the skin and clothes became quite evident.

Omega back case with marks

Actually, the blackish, greasy smudges that form on silver and are released on the skin come from the copper present in the alloy that composes the silver case of your watch.

Silver is not only silver

Remember that this alloy is composed in percentage by the precious metal – for example, in an 0,800 watch, 80% of the material is pure silver. The rest is made by other metals, which help to strengthen the alloy a bit, as in its natural state, silver is quite soft.

Typically, the other metal used in silver alloy is copper. And copper suffers from oxidizing when in contact with your skin. The most common stains from silver are black and occur when the silver tarnishes due to a reaction with gasses in the air.

This was not an issue when watches were worn on the pockets, but became rather important when they migrated to the wrist and came in constant contact with the skin.

Watchmakers found other alloys that looked like silver, like argentan, know as German silver – but still, most of the metals used to make these alloys had this kind of effect, or had other issues, like being prone to giving allergies to the skin, like nickel.

One of the only metals that is inert – does not give allergies and does not change its aspect in time – is stainless steel. So, when the price of stainless steel became more affordable, and the technique changed as well so the production was easier, watchmakers started using it instead of the previous solutions like plated metals (gold-plating and chrome-plating).

A beautiful Longines with a silver cushion case

The modern saver: rhodium

While silver might cause allergy issues, there is a metal which is currently used for plating, both base metal and other precious metals, and it is rhodium. It gives a luminous sheen and a great lustre, so much that it is often used on other alloys to give them this “precious” look. And lots of modern silver jewelry is rhodium-coated.

Rhodium, however, has some drawbacks. It is brittle and rigid, so you cannot use it by itself, and has a high cost – more than the famous “noble” metals (silver, gold and platinum). More, even if modern plating techniques are much better than old ones, in time rhodium wears off, exposing the underlying silver and presenting again the same old issues that it had before.

So, what to do if you have a silver watch and you want to avoid it smudging and staining your skin and clothes?

The use of clear nail varnish

Apply a layer of clear varnish on the metal where the watch touches the skin. The varnish will be invisible and form a layer that will impede the silver to contact your skin – and so, will not oxidize and smudge skin and clothes.

When you see that the smudging starts anew, it is much better to remove the layer left on the back case, and put a new layer of nail polish on: if you apply a new layer over an old one, you risk that it starts yellowing.

You can find much more about horology and its fascinating history in The Watch Manual, a thorough e-book that explains all the basics about watchmaking and its protagonists.

To download a FREE 8-chapter extract from The Watch Manual

The secret beauty of watch decorations

While we know that complications in a watch make the most of its value and price, let’s not forget another quality that renders luxury watches genuinely precious. And this is the presence of finishings and decorations, both in the movement and its case.

And we are not talking of the presence of precious metals and gems in their making, but about the human craftsmanship that has been poured into making that particular element, beautiful.

As strange as it may sound, luxury timepieces offer precisely this. Every element and component of their structure, both the case and the movement, is not just built: it is often polished, carved, decorated somehow. Even where you cannot see. Even on the surfaces that are not exposed.

Cotes de Geneve on this Universal Geneve movement

This refinement is an activity that stays in a middle realm between the functional and the decorative aspect.

More often than not, these tiny elements inside a watch are milled, polished, and decorated, so to be exceptional in every way when you happen to look at them.

Initially, these processes, which were entirely made by hand, had a practical purpose, apart from the aesthetic aspect. Watches have always had a huge issue: that is, the effects of dust inside the movements, as cases were not dust-proof and waterproof in the early days of watchmaking.

Dust tended to accumulate in recesses, and so, clogging up the moving parts, especially the pivots of the wheels, and affecting timekeeping.

So, watchmakers started to create textured surfaces on the metal surfaces of movements, so to “trap” the dust
in excess by making it deposit itself there, and not in the moving parts of the movement.

The two main surface finishings of movements

The first is called “Cotes de Geneve” (stripes of Geneva). It looks like a series of satin stripes practiced over select areas of the movement, mostly, non-moving parts, like bridges.

Perlage on an Eberhard movement

The second is called “Perlage” (pearling), and also known as circular- graining or stippling.
It consists of applying a pattern of overlapping small circles with a rotating abrasive tool.

While the Cotes de Geneve finishing can be automatized, the perlage cannot, especially in the most intricate details, so it requires manual intervention. More often than not, a single movement is decorated with both patterns in separate areas.

A second finishing, which cannot be totally automatized, is the so-called “anglage” (angling), also called chamfering.

In anglage, the edges of an element are filed with a 45° angle between the two orthogonal sides. The resulting surface is generally highly polished to make it shine brightly, and there is a very sharp edge on the corners between the surfaces. This edge and the polishing cannot be obtained with purely CNC-driven means, so anglage is mostly hand-made, or better, hand-finished.

Before and after, showing the result of black polish

The lustre of black polish

Black polish is not a decoration, but a way of polishing a surface. When a surface is planar and perfectly smooth, light reflects over it, giving a black effect. Black polish is made by hand by scrubbing the surface with special diamond pastes, more coarse at the beginning, and progressively smoother at each passage.

As you can understand, it is an incredibly time-consuming process.

As a final note, sometimes surfaces are also engraved, and the best engraving is handmade. Usually, the brand of the watch is inscribed on the movement, with some other writings and seals. Other times, bridges and other elements are engraved with decorations in bas-relief, making them almost a work-of-art.

Blued screws

Another critical aspect of decorations in movements is the presence of screws, which are of a different color than other elements. This happens because traditionally, screws were tempered at a high temperature so to render them harder.

The different temperatures used in tempering gave them a different color, one of the hardest being a bright blue. This is the reason why in some luxury watches you see screws of a bright blue color. Companies like Lange und Sohne and NOMOS Glashutte are well-known for their use of this technique.

Even if today the blueing can be obtained through a chemical reaction, high-end manufacturers still use the traditional thermal blueing of screws.

Now consider applying these techniques and finishes to every one of the mechanical pieces composing the 300 of a typical complicated watch (that is, a watch featuring different exotic functions). And we mean the inside of the movement, as well as the outside.

Remember that cases, bezels, and backs are often polished with different finishes, shiny and satin-like, and this work cannot be done entirely automatically.

A handcarved movement in a pocket watch, around 1850

The beauty of handcarving

Cases and movements can be carved by hand so to reproduce scenes like this one. As you can see, the bridge has been carved to display a woman, who is sitting under a tree and holding a bunch of flowers, in front of a lake. This exquisite craftsmanship was completely hidden from view under a cuvette. Still it was there , ready to be shown as a surprise effect to the watch owner’s friends.
It is rather evident that this effect has nothing to do with the functions of the watch: it is just an aesthetic display made to appease our sight.

The same can be said for decorations made on the case of a watch, or even, on the dial.

You can find much more about horology and its fascinating history in The Watch Manual, a thorough e-book that explains all the basics about watchmaking and its protagonists.

To download a FREE 8-chapter extract from The Watch Manual

Jewels in watches are much more prosaic than their name suggests.

When we read about terms used in mechanical watchmaking, we often hear terms like “jewels” or “rubies,” and we often fantasize about the hidden riches inside our watches. There are some fiction stories where thieves steal the jewels of a watch!

Well, the term “ruby” or “jewel” is used to refer to tiny artificial stones (jewel bearings) that are set inside the watch. They are shaped like a torus, are man-made, and I must add, practically worthless – sorry for shattering your dreams of becoming rich in this way.

If you examine a watch movement, you can notice that these rubies are set in particular places (so, they are not ornamental, even if they do have a definite decor effect).

They are usually set in pairs (one above and one below) in correspondence of the pivots of the gears, and they are generally drilled through with a tiny hole.

Cross section of jewel bearings

You can see it here (it’s a cross-section) what it happens. The pivots of the gears are set precisely through these stones, one up, one down, so they can rotate freely.

And why using jewels instead of plain metal bearings? (mind you, lots of watches use bearings too – especially lower-cost mechanical watches and quartz mechanisms).

The answer is, because of attrition.

Attrition and jewels

First of all, a small note. Everybody knows that the hardest substance on Earth is the diamond. The hardness of materials has been measured by a scale, known as Mohs Scale. The diamond has a value of 10 on this hardness scale. On the other hand, the talc, with just a value of 1. Most of other materials stay between these two extremes. Well, corundum has a value of 9 on the Mohs scale – and rubies and sapphires are two forms of corundum. Metals have a lesser value by much: gold has 2.5, brass and nickel have 3, platinum has 4, iron and steel 4.5, titanium has 6, and tungsten carbide has 9.

You can see that a jewel is harder, even if more brittle than its metal counterpart, the bushing, so a steel pivot rotates inside it more effortlessly and with less grinding on it than it would in a bearing made of metal (usually, brass). The static coefficient of friction of brass-on-steel is 0.35, while the one of sapphire-on-steel is 0.10–0.15, so three times less.

It means a smoother and better transmission of movement, less attrition, and extended durability of the watch without constant maintenance.

As you can easily imagine, setting a jewel inside a micro-mechanics element like a bridge of a watch is a complicated issue. This means that jewel setting used to be reserved for higher-quality (and higher cost) watches.

Nicolas Fatio de Duillers

Use of jewels in watchmaking

Jewel bearings were introduced in watches by Nicolas Fatio (or Facio) de Duillier and Pierre and Jacob Debaufre around 1702. Still, they did not become widely used as they were very costly. The first jewels were, indeed, shards of real gemstones. Watches often mounted garnet, quartz, or even glass; only the top quality ones mounted sapphire, ruby, and even diamond jewels.

In 1902, everything changed, because Auguste Verneuil developed a chemical process to create synthetic jewels. Hence, they became quite cheaper and gained widespread use in watchmaking. Jewels in modern watches are generally rubies or corundum, one of the hardest substances known (apart from diamond).

So, modern watches tend to use jewels on every part that is subject to constant grinding of metal against metal. This includes the pivots of the wheels of a typical wind-up watch (wheel train, escapement wheel, balance wheel), as well as two other critical elements: the pallet fork endings and the single impulse jewel in the center of the balance wheel.

Along the more ordinary torus-shaped jewels housing the pinions of the wheel train wheels, we also have some unique jewels called capstones. These jewels are used in wheels where friction is critical, as the balance wheel pinions. They are set so to prevent the shaft of the wheel from touching the surface of the jewel, and also, to create a space called “oil cup” which helps to lubricate the mechanism better.

More often than not, these capstones are held in place with shock-resisting mechanisms, such as the Incabloc.

Jewel-count. Beware of exaggerations!

Before the introduction of shock-resisting systems (around 1932), the best wind-up mechanical movements without complications mounted 15 jewels. After that, the jewels rose to 17. Automatic and complicated movements usually mount more jewels, as they have more wheels requiring them.

Waltham Autochron, mounting 100 (useless) jewels

From their introduction, watch manufacturers defined the quality of the movements using terms such as “XX Jewels,” where XX was the number of jewels mounted into the watch.

This term diffused itself in product descriptions, becoming a natural equivalence to the public of “more jewels, more quality.”

So much that some companies, between which Waltham and Orient, launched on the market watches featuring 100-jewel movements. These movements used aesthetically-placed jewels, which had no function whatsoever, except to let the manufacturer say that there were 100 jewels inside the watch.

This example is a practical effect of the fascination that a name like “jewel” can have on someone who does not know the functional aspects of jewels inside a watch.

We should note that this practice, which was deceiving for the customers, was first condemned, and then prohibited by law.

Today, a manufacturer cannot place jewels inside a movement that have no practical purpose. If it does, he cannot refer to them in its communication.

You can find much more about horology and its fascinating history in The Watch Manual, a thorough e-book that explains all the basics about watchmaking and its protagonists.

To download a FREE 8-chapter extract from The Watch Manual

What to do if water has gotten into an old Rolex and is fogging the glass?

As time goes by, watches lose their water resistance. It happens. And if you are experiencing this issue, well, you have a couple solutions.

The easy solution is as follows.

Get it to your watchmaker for a service, quick.

Rolex uses a unique kind of closure for its watches (the famous – and patented – Oyster case) which requires a special tool for opening. This tool follows the small indents at the base of the backcase, so rotating it you can unscrew it. It is not available to everybody, and only watchmakers normally have it. Of course you could buy it, but it is both costly and not really suited to DIY. Remember that a false move might make you scratch deeply your watch. Not really an issue on a Seiko 5, but on a Rolex, it hurts.

If you leave the moisture inside the watch, some parts of it would start to rust, and this is something that you do not want at all.

Do not try to do anything by yourself. If you do not know what to do, you could eventually make something wrong, and to remedy it it would be costly or downright impossible.

You might manage to remove some fogginess through the use of different methods, like rice, silica gel, cat litter and such, but it would require you to remove the back of the watch to be effective. Are you really ready for that?

The hard solution requires instead some manual dexterity, and involves significant risk to the watch itself. Plus it will void your warranty, if the watch had one.

Please note: what follows is a somewhat detailed description of the procedure needed to open up a Rolex.

I have been asked in other platforms why should I give this detailed how-to guide to anyone, as the good and right answer is obviously the first. I did not want to boast my operational knowledge of habillage: I just wanted to explain the reasons why lifting the back of a watch to let go the vapor formed inside – as it would be logical to do – is easier said than done. If I did not, anyone reading could assume it was an easy task – something that everyone could safely achieve, and save a few bucks. Well, as you can see, there’s much more into it – and this is what your watchmaker does when servicing a watch (any watch) that has this kind of issue, not just a Rolex.

So, caveat lector – proceed at your own risk.

Here’s the Rolex opener tool I was talking about before. This one is a Chinese-made compatible one. It is made of soft, low-quality steel, so it is good for few uses – but it is relatively affordable (around 30 USD bought online). Good quality ones featuring professional components and materials – that is, watchmaker’s quality – are made by companies like Horotec and Bergeon, but they cost significantly more (like 5 times more).

As you can see, you have to place the die over the watch when it is properly held in a vice with its back upwards.

The four teflon/hard plastic holders ensure the watch does not get scratched if something slips out of control.
What follows is a typical Oyster case back. As you can readily understand, you need several dies to find the one which fits your watch size, as we have many diameters, from the Ladies tiniest to the Gentleman’s biggest. When you have secured the watch case into the vice, and the vice has been placed in a bench vise, you are now ready to put the wrench into the die, press hard against the back of the watch and turn so to unscrew it.

If you do not place everything perfectly aligned, and something slips, well…

You could end up with something like this. That is, a severely scratched back which would require an intensive work to return to a good state (not pristine anymore – if you scratch something, you remove material from it). Even if a professional polishes this watch, the deep scratches on its base will continue to be noticeable.

Let’s pretend you have done everything right, and managed to remove the back safely and securely. You end up with this situation.

Congrats. You’ve made it!

Now, place your watch like this under a closed container so to protect the watch movement from dust. You could place a couple packets of silica gel next to it, but not really necessary. Leave it like this for a couple days. Then proceed to screw the back again into the watch, with all that this action entails.

Remember: if water got into the watch the first time, it is because it found a way to get into it first!

This means that either you had not screwed the crown in fully, or the o-rings protecting the watch have to be changed or serviced, because they are not water resistant anymore. So now you have a new problem to solve: to ensure that your watch is water resistant again.

Watches have different kind of gaskets, often made in silicone, which have an operative life of around five to ten years, and they must be periodically greased and changed to ensure they stay water-resistant. You can see it in the Rolex back, housed in a recess around the back opening.

They are applied to the backs, as well as to the crowns. Yes, these tiny gaskets on the winding stem have to be periodically lubed and changed as well to ensure that the watch stays water resistant.

When you have done all of this, now you can check if the watch is water resistant again. You’d need someone who has a kind of tool for that, though, since doing it traditionally – that is, in water – would be dangerous, especially if you have made a mistake and the water resistance is impaired somewhere…

You can get a hobbyist-level one for around 300 USD, but the good ones can cost you five times more.

Well, now you have finished, and your watch has no moisture into it anymore, nor will get any later!

If you have gone this far, you could start thinking about selling watchmaking services to your friends, family, and acquantainces.

As you are now thinking, this service is something that professionals usually do – for a few bucks. This knowledge, and tools assortment, are better used by a professional. And the answer is yes: unless you are a serious hobbyist, or a professional, do not even think about doing all of this by yourself. It would possibly make the problem bigger and more costly to solve.

You can find much more about horology and its fascinating history in The Watch Manual, a thorough e-book that explains all the basics about watchmaking and its protagonists.

To download a FREE 8-chapter extract from The Watch Manual

Has anyone ever bought a watch and found it was going backwards?

While the possibility seems intriguing, this would happen only if the watch was designed to do so, like in the original watch issued by Apple, and in some contemporary watches made for specific purposes. It is impossible that it happens by mishap.

A couple of unusual Franck Muller timepieces

There are watches built to run like that, and some come from famous brands as well, as these two Franck Muller demonstrate. However, if you mean that it could happen because of a technical fault, the answer is negative. Except by a demonical possession, that is.

It is technically impossible. And I will walk you by it and explain why.

There are several reasons why an ordinary watch – that is, one running clockwise – cannot run backwards.This would mean that I will be explaining a bit how a typical mechanical watch works.

1 – the shape of the arbor

three different arbors

First of all, to make hands turn backwards its wheels should rotate on the other direction – counterclockwise. This means that in a regular watch, in order for this to happen, the watch mainspring should be mounted on the opposite way. While this would be ideally possible, it could not happen, because if you do so the mainspring would not hold onto its central axis (called arbor).

The mainspring has a hole on one end (as you can see in the photo), and is coiled around the arbor when you wind it.

As you can see, however, the arbor has a sort of nail where this hole gets into – but you can also notice that its shape is eccentric: it has a sort of inner recess where the end of the mainspring goes.

If you try to mount it on the other direction, it will not stick in the nail, because the shape of the arbor would make it slide away. This is a sort of safety measure as well, so you have to mount the mainspring in the right direction.

Mainspring and bridle

2 – the direction of the click

The click is a small rotating element fitted on the ratchet wheel. When you wind up a watch and hear that click click click sound, well – this is the click in action. It is very visible in this photo at eight o’clock – the small rotating element on the left, which is a sort of safety mechanism equipped with a three teeth and a small spring holding it in place.

The function of the click is to let the ratchet wheel rotate in one direction only, thus storing energy in the mainspring. When the wheel tries to recoil, the small spring in the click makes the click rotate, so its big tooth engages the teeth of the ratchet wheel, effectively impeding it from rotating back.

The only way to do so is to manually rotate the click out of the way and hold it in place as the mainspring discharges itself. Incidentally, you can control its discharge by holding the crown, so it does it slowly. This means that the stored energy of the mainspring cannot release its energy by simply turning back, and can only be released from the other end of the energy distribution chain – that is, setting the movement in motion.

So, even if you somehow manage to assemble the mainspring backwards, it could not rotate on the other direction, because the click would intervene and stop its rotation.

A typical manual winding movement

3 – the shape of the escapement wheel and pallet fork

The escapement wheel is at the end of the wheel train, and is the one propelling the pallet – which most normally is in the shape of an anchor. You can see them below, the escapement on the right and the pallet on the left. The escapement is called a wheel, but its teeth are quite different from the ones used in normal gears.

Escapement wheel and pallet fork

As you can see, they are not symmetrical. This means that the escapement is made to turn in one direction only. If you try to make it turn in the other direction, it would not, because its teeth could not effectively engage the two ends of the pallet fork, and get stuck.

You can readily see that the pallet fork itself is not symmetrical, either. One arm is longer than the other, and the two rubies are set at different angles. This means that to make it run in reverse, you’d have to mount both escapement wheel and pallet fork upside-down, which is obviously impossible as they would not fit with the other elements of the watch.

So, to end…

As you can see, making a mechanical watch work in reverse is impossible, since its construction is made to let the mechanism rotate in one direction only. To rotate backwards, a watch should be designed to do that: it cannot just happen by mishap.

You can find much more about horology and its fascinating history in The Watch Manual, a thorough e-book that explains all the basics about watchmaking and its protagonists.

To download a FREE 8-chapter extract from The Watch Manual