Image: Tissot
Though we spent plenty of pages last year looking at high-tech ceramics in watchmaking, the most timely story to pursue would have been titanium. As you no doubt know, dear reader, 2020 marked 50 years since Japanese watchmaker Citizen introduced a titanium watch. Given what is (still) happening in the world, you may not have noticed – and nobody would blame you of course.
It is relatively easy to identify the material benefits of titanium versus stainless steel, and the opposite of course. It is not the case that one is simply better than the other, which is where a few definitions can help shed some light. Now, if you recall the David Guetta number called Titanium, you might have the wrong idea about this metal. Nevertheless, the metal has a mythical reputation, which watchmaking brands often lean into.
Reality paints a different picture, which does not take anything away from titanium’s virtues. It is best to embrace this approach because if you buy a titanium model over a steel one because you are convinced of its superpowers, you will be in for some rude surprises, while simultaneously missing some very impressive facts.
This might seem needlessly nerdy, or perhaps pedantic, but think of it this way: if you love cars, you probably also know something about how they work. Also, titanium watches can be more expensive than the same in steel, just like ceramic. No doubt there is a limit to what you want to know, and we have tried to draw from and summarise from a number of sources here.
For further reading, we will recommend some excellent materials (online as far as possible), but also if you want to skip the purely technical definitions and get on to the pure value of titanium as it relates to watchmaking, you are of course free to ignore whole sections, as you please. That said, there will be a very necessary nerd-out in this special section.
Titanium features in movements, not just cases, as demonstrated by the movement of the Romain Gauthier Insight Micro-Rotor Squelette Manufacture-Only Carbonium Edition
First, we must spare a few words about this special focus on materials, a recurring thematic chapter for WOW. It represents an effort to build editorial bridges and structure across the years, and it happens to bear a passing resemblance to how watchmakers plan their releases.
In planning this section, we ask ourselves why this material at this moment. We start thinking about this section a couple of years in advance. As a further clarification, we can say that we actually have a shortlist of materials, and we cycle to the most relevant one.
Once more, this has nothing much to do with trends, and titanium is not trending – it is already an accepted part of the watchmaking landscape, from Switzerland to Japan. It is even a staple at all levels of watchmaking, fine and otherwise. You probably have a watch in titanium, or you know people who do.
It is because of this that we, the watch collecting community, know there is no hidden danger in this material. There is no need for caveat emptor statements; a watch in titanium will not shatter or possibly stain your clothes. Titanium is as reliable in this regard as steel and gold, and perhaps goes a good bit further than either in some areas.
Our present moment showcases a particular strength of titanium. In these trying times, going with ceramic and titanium is very obvious because these are both hypoallergenic. This feature might even mean both materials will become ever more popular for all sorts of wearables.
Gear Patrol even calls titanium the most comfortable material in watchmaking. While we will not go so far, it is telling that many watch brands opt for titanium casebacks in their bronze models, and that TAG Heuer, Montblanc and Tissot all use the material for their connected watches.
Now, given that titanium is hardly new in watchmaking, a specific approach was needed here. The section is thus organised into a few parts, as follows:
History, both general and specific to watchmakingMaterial PropertiesPros and Cons: steel versus titaniumMilestones in watchmaking
The aforementioned definitions are to be found towards the end of the section, before the next major part of our materials special.
A big part of the appeal of any material in watchmaking is the story. Cynics and realists will call this the marketing aspect, but this plays a real and valuable role in what makes titanium appealing as a material in watchmaking. On that note, it is time for a history lesson, because that is where the story begins. Unlike most other materials though, we need only go back to the aftermath of the Industrial Revolution in Europe.
The Omega Seamaster Planet Ocean Ultra Deep Professional is made from the same stock Grade 5 titanium as the hull of the DSV (deep submergence vehicle) of Victor Vescovo that went to the bottom of the Mariana Trench
Contents
Titanium in the world
If you know anything about titanium, then you may agree that one of the most overlooked aspects about this metal, compared with steel, is that it is a metal, not an alloy (see Material Properties). In watchmaking terms, it is best to think of titanium as one thinks of gold, because there are many versions in play, based on the other materials mixed in. This story will refer to grades of titanium, where relevant, and generally not distinguish between commercially pure titanium and other titanium alloys, except where noted.
Unlike the previous subjects of our special focus on materials, titanium has not been in use for very long. It was only discovered in the 18th century, by amateur geologist and clergyman William Gregor, in Cornwall, England. It was named, as you might think, for the titans of Greek mythology, although the material properties that we know today would have been a surprise to Martin Heinrich Klaproth, the Prussian chemist who named it thus in 1795.
No one could find a use for the metal outside the laboratory until 1932, because producing it from the raw ores it was present in was impractical. Luxembourgish metallurgist William Justin Kroll solved that via the process that bears his name, which is still in use today to extract titanium from raw ore.
Despite the wondrous name, there were no applications for this metal from its discovery all the way to the mid-20th century. The Soviet Union first recognised the potential of titanium in military applications, and the US followed suit, bringing the material to the world of aviation by the 1960s.
No less an authority than Wikipedia confirms that the US Department of Defense supported commercialisation of titanium, in a famous example of tax-payer funded spending creating completely novel commercial opportunities. The jets such as the F-100 Super Sabre introduced titanium to the public eye, and thus shaped its image. In other words, if steel defined the 19th and 20th centuries, titanium would take the world into the future.
Citizen Watch has been making prototypes for the lunar lander.
Jets such as the A-12 by Lockheed Martin captured people’s imagination, when they belatedly became aware of it of course. The A-12, for example, was the precursor to the SR-71 Blackbird, which is probably one of the best-known aircraft in the world. Indeed, it still comes to mind when people think of the Cold War era’s defining military aircraft, alongside the U2 spy plane.
One particularly interesting bit of news from this period that is still striking is how the US managed to acquire enough titanium for these advanced jet projects. The problem was that the Soviet Union had the largest stockpiles and produced the most titanium in the world (today it is China – Ed). The Big Red Threat was actually experimenting with making submarine hulls out of a titanium alloy, so it had developed the expertise and supply that no else had.
Given that A-12 and SR-71 projects were driven by the CIA, the agency came up with a nicely capitalistic strategy to deal with the problem – buy the stuff from the Soviets. Needless to say, it worked, and laid the foundations for the contemporary aerospace industry.
Today, some two-thirds of all titanium produced goes into this industry. In these kinds of volumes, titanium sped into people’s consciousness rapidly, but it was another feature of the Cold War that made titanium legendary: the space race. In the 1970s, when the US shuttle programme was on the drawing table, titanium first entered the picture.
The aforementioned issues that plagued the Air Force with the CIA programmes meant that NASA had developed a preference for aluminium, which was also cheaper. The command module that brought Neil Armstrong, Buzz Aldrin and Michael Collins back to earth was largely made of aluminium, for example. The Apollo programme did use titanium, in particular for the fuel cells, and certainly had an understanding of the value of the metal (and its alloys) to their endeavours.
Eventually, the engineers at NASA figured that, with titanium’s better heat tolerance (see Definitions), it might actually be a more practical solution than aluminium after all, while also being cheaper because the material would require a less robust heat shield (sourced from publicly available NASA documentation – Ed). Given that the space shuttle was meant for reentry into our atmosphere, and to be reused, this was a big deal.
To make a long story short(er), titanium remains a big part of the space programme in those countries that have one, and the European Union of course. Interestingly, Citizen Watch is working with Japanese private space exploration firm ispace on the Hakuto-R project on what might be the world’s first commercial lunar exploration programme. The Japanese watchmaker is making prototype parts for the lunar lander’s legs in the brand’s signature Super Titanium (more this elsewhere in this section).
This is actually the most direct example we have of actual evidence of watch firms working with space agencies to do anything other than keeping time. This one is commercial but is indirectly linked with the Japan Aerospace Exploration Agency (JAXA).
Of course, the most famous brand associated with the space is Omega, and its advertising campaign with George Clooney to commemorate the anniversary of the moon landings in 2019 makes the case for why people were so interested in everything that made the space programme tick.
From Sputnik onwards, the public were interested in both the reality and the fantasy of space travel. People of a certain age were sold on eating and drinking what the NASA astronauts did; this trend may have passed but the interest in space-age materials remained.
Image: Breguet
Back on earth, titanium made its way into the automotive industry. One might imagine plenty of opportunities here, but the relatively high cost of titanium is a significant stumbling block. Once again, it was – and remains – a race between steel, aluminium and titanium, although these days carbon fibre is also in the mix. Just like the space race, aluminium is the preferred option, thanks to both depth of expertise and availability of raw materials.
Even today, titanium tends to get lumped in with exotic materials such as carbon nanotubes, although it is more of an OG like carbon fibre. Like carbon nanotubes and such, titanium tends to be reserved for high performance motorsports, where the cost of the material can be justified. To be clear, the material itself is not that expensive, machining it is (see Definitions).
Being a little expensive, for whatever reason, does not hurt titanium’s reputation as far as watchmaking goes. Too expensive for space? Sounds like a marketer’s dream, but the story begins on uncertain footing because titanium is hardly what one could call rare, by any measure of that word (see Material Properties section).
Even as titanium struggled to move beyond aerospace, it was its high corrosion resistance that drew the interest of other industries. Specifically, titanium proved very interesting to doctors and specialists in biotechnology. Since it is extremely biocompatible, it is attractive for internal medicine. Here is what the professionals have to say about it:
Titanium alloys are biocompatible in nature. They commonly contain amounts of vanadium and aluminum in addition to titanium. The most used titanium alloy in knee implants is Ti6Al4V. Titanium and titanium alloys have great corrosion resistance, making them an inert biomaterial (will not change after being implanted in the body).
compared to other metals used in knee implants. Additionally, the elastic nature of titanium and titanium alloys is lower than that of the other metals used in knee implants. Because of this, the titanium implant acts more like the natural joint, and as a result, the risk of some complications like bone resorption and atrophy are reduced. – Prasanta Sahoo et al; Mechanical Nature of Biomaterials; 2019.
This appears to be a growth area for titanium, and was cited as a potential application for the gold and titanium alloy developed by researchers Emilia Morosan and Eteri Svanidze at Rice University, USA
Titanium in watchmaking
Last year was actually the 50th anniversary of the first wristwatch made in titanium. The honour goes to Citizen, which rocketed ahead of the entire watch trade. This is the somewhat famous Citizen X8 model, and the firm says that it went with titanium because of the Apollo missions. Some observers suggest, off the record, that the Japanese firm was too quick – an assertion that Citizen jumped the gun, in other words.
There is some degree of prejudice in such sentiments, perhaps, because Japanese watchmakers were humbling the entire Swiss trade throughout the 1970s. Perhaps illustrating this point, rival Japanese watchmaker Seiko followed Citizen with the world’s first dive watch in titanium in 1975.
What is factual though is that titanium took awhile to gain favour with Swiss watchmakers, first making waves with the 1980 Porsche Design Titan Chronograph. Built in partnership with IWC, the watch was developed by Lothar Schmidt, the man behind Sinn, which the man himself told us about while explaining his keen interest and expertise in materials.
This watch only became more popular over the years, attaining a sort of iconic status that obscured the efforts of Citizen and Seiko in this area. In 2020, various online publications ranging from ABlogtoWatch to Monochrome published stories about the Citizen X8, noting that Porsche Design is sometimes incorrectly credited with bringing titanium to watchmaking.
Near as we can tell though, this Porsche Design collaboration with IWC did the trick for Swiss watchmaking as plenty of brands jumped on the bandwagon. Coincidentally, this was roughly contemporaneous with the era of the space shuttle at NASA. The first space shuttle, Columbia, launched in 1981, though the programme was in development from 1969.
Fittingly, both titanium and high-tech ceramic captured the public’s imagination in the 1980s, allowing for all sorts of material experiments from watchmaking firms. The big Swiss names were still suffering from the quartz hangover and material experiments allowed them to strut their stuff, so to speak.
And so it was that virtually every brand began offering something in titanium. Well, not every brand but definitely enough that titanium cases and bracelets became fixtures, rather like steel and gold. Like the other staple materials in watchmaking, it is deployed freely across every level of watchmaking.
The key to titanium’s success lies in the aforementioned adoption of the material by the biomedical industry. If titanium is good enough to spend a lifetime inside the human body, without ill effect, then it is certainly suitable for a material destined to live on skin. That is the logic that prompted the bold Gear Patrol assertion, and the nature of titanium bears this out (see Definitions).
As for the future, we were excited to report on the development of promising titanium and gold alloys back in 2016, and WatchesbySJX also picked up the same news. While we have been eagerly scanning new releases since then for this novel alloy, we have yet to see it.
Tudor Pelagos in titanium, with ceramic bezel insert
Behind the curtain: What makes Titanium special?
In Tudor’s video introducing the Black Bay 925, they have a cheeky moment when discussing how exactly that silver is made – that is to say the alloy’s constituent parts that make it impervious to base silver’s tendency to tarnish. Even if you do not know anything about silver, nor own anything in the material, you might have seen or heard stories about silverware and how it was prized by upper crust Western families. There is always some reference or other to “good silver” as if there were a bad kind, or something. Alloys are never a simple matter, unfortunately, but we digress.
The funny bit about the Tudor video was that it showed the component parts of the silver alloy as a fine dust, with the illuminating message that they used a bit of this and a bit of that. Even the colours were not particularly helpful. It was all in the spirit of fun though, and that is perfectly fine.
By way of contrast, the Omega presentation of their bronze gold variant was painstakingly meticulous. Once again, alloys change the nature of the game significantly. Here is what makes up 904L stainless steel, to illustrate the point:
Nickel, 23-28%Chromium, 19-23%Carbon, 0.02% maximumCopper, 1-2%Molybdenum, 4-5%Manganese , 2% maximumSilicon, 1.0% maximumIron, (balance)
The different percentages could have serious impacts on how the alloy works, and indeed how hard it is to work. The same is true of titanium alloys, but first an important note. If you have a watch cased in Grade 2 titanium, then that is commercially pure titanium; yes, commercially pure titanium is suitable for use in finished products. This is one of the amazing things about titanium, and is quite unparalleled (as far as watchmaking goes). So what is titanium anyway?
A metallic element, titanium appears grey, or perhaps like unshinning silver. In other words, it is colourless and not particularly lustrous. Its chemical element symbol is Ti and its atomic number is 22. A Group 4 transition metal, it lends its name to its grouping of metals, including zirconium (Zr), hafnium (Hf), and rutherfordium (Rf). This is sort of like the more famous platinum group.
Comparing the weights of the same Citizen watch, with different materials.
One of the main benefits of titanium, as demonstrated in its extraordinary use in the aerospace industry, is that it offers a high strength-to-weight ratio, also known as specific strength, creating an extremely strong substance. This simply means that titanium is relatively strong at low weight. The easiest way to think about this, in terms of watches, is to consider the difference between a watch in titanium and a watch in steel, if they are roughly the same size.
The best case scenario is to consider the exact same watch in steel and in titanium. As you can see in the above image, same watch, different materials for dramatically different weight. The titanium watch might be somewhere between 40-50% lighter than the same in steel.
Does this mean that this titanium model is stronger than the same in steel? Well, not really. A steel watch that weighed the same as a titanium one? If so, then yes the titanium version is stronger. This is one of the points that marketing messages often obscure, unintentionally (most of the time).
When watchmakers create models in titanium, of something that exists in steel, they are effectively making something lighter, not stronger. It is the lightness, with relatively good strength, that makes titanium so useful. The titanium watch is much stronger at its weight than a steel watch would be, at that same weight. Titanium is simply less dense than steel, and certainly than iron.
To continue the little experiment with the same watches as above, holding each in your hands gives a clear indication of the difference in weight, but little sense of any difference in strength. You might be shocked to find that the both would be rated the same for strength, relatively and informally of course. Hardness, something else that you cannot tell from a simple physical examination, is another matter.
Now, titanium offers a high level of mechanical resistance, otherwise known as mechanical impedance, making it extremely durable. It would not be suitable for a long-wearing item such as a wristwatch otherwise. It would certainly be no good for something like a dive watch, where it will be expected to take a beating and keep on ticking, as the saying goes.
Unlike ceramic for example, titanium does not easily reach critical failure. In other words, it bends but does not break, like steel and aluminium. The point that it deforms is not that important here, but we will explore it a little.
To compare between metals, it is necessary to introduce a titanium alloy into the picture, which for our purposes will be Grade 5. This is an alloy of titanium, aluminium and vanadium under the following formulation: Ti- 6Al-4V (see Grade 5 titanium). For stainless steel, we will use the standard 316L that most watchmakers favour.
We will use ultimate tensile strength here, with 316L clocking in at 485 MPa and Grade 5 rated at 1,170 MPa; MPa stands for megapascals, a unit of pressure. This does not mean that titanium is simply stronger, because some kinds of steel can reach 3,000 MPa.
As an outside reference here, aluminium is rated at 50MPa, and that is among the reasons why cases are so rarely executed in this material (again some alloys and forms offer different properties).
On the matter of hardness, we will use the Rockwell scale (see Hardness). Approximately, 316L registers 79 while Grade 5 registers 41. Now there are some subtleties to this measure, but broadly speaking this result speaks to the point some collectors have noted on forums about titanium being softer than steel.
Again, there are treatments that increase the hardness of both steel and titanium (famously Duratect from Citizen, and DLC just about everywhere else), but this has an impact on one of titanium’s more attractive properties.
In the air, titanium creates a powerful oxide layer that prevents the material from reacting any further (see Passivation). This has the effect, in watches, of titanium cases looking less obviously scratched than stainless steel cases. The muted colour of titanium helps here too, but the effect is similar in Grade 5 titanium that has been polished. Of course, surface treatments upend all this, and should be considered when discussing with your friendly neighbourhood sales specialist.
A dramatic illustration of Citizen’s Super Titanium and stainless steel in saltwater solutions. Can you guess which is which?
We can report from a variety of collectors (including this author) that titanium watches pick up lots of dents and nicks, but these add character to the watches without detracting from the aesthetics. Again, this is mainly in the versions that are not polished. The contrast that is most useful is what happens when your case gets scratched and when your sapphire crystal gets a nick. The latter is more visually disturbing.
The main benefit of titanium versus steel though, as far as watches go, comes down to its corrosion resistance (see Passivation). This is a defining characteristic of titanium, and carries over to most of its alloys. It marks the metal as quite special, as noted in the previous segment on why the biomedical field uses it. In simple terms, a watch in titanium will not react to fresh water, sea water, typical swimming pool water, alkalis, acids and just about anything. It is the next best thing to platinum, but is much cheaper, obviously.
Titanium also sports high heat transfer efficiency, which is one of its selling points when used in the aerospace industry, and also the space shuttle as mentioned earlier. On the wrist, the practical effect is that the metal stays at a relatively standard temperature, not getting too warm or cold depending on the ambient temperature. In other words, a titanium watch is excellent in very cold weather, which is a benefit well-known to seasoned watch collectors.
Another interesting feature of titanium is in the oxide layer’s photocatalytic properties, which are well understood when discussing TiO2 in various forms. The oxide layer on any given titanium or titanium alloy might only be 1nm thick, and cannot really be easily separated from the metal.
This oxide layer interacts with UV light, and the powdered version is used in sunblock. The effects of this photocatalytic ability, as it relates to wristwatches, might be to make them self-cleaning. You would just have to leave the watch exposed to direct sunlight, and turn it over now and then.
As for cost, titanium is more expensive than steel, primarily because it is relatively more difficult to machine (it has to be worked in a contained setting with inert gasses such as argon) and somewhat more expensive to process. The cost has little to do with rarity.
In fact, it is the seventh most abundant metal on earth, but it is mainly present in igneous rocks such as ilmenite. It is correct to note that pure titanium in its natural state would be rare, with a special exception. As highlighted by Panerai recently, titanium is also used in a recycled state, which is important in supplementing the use of this metal.
We get into more details on this in the “No Lightweights These” part of our two-part article series, coming soon.
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