Hands On With The Citizen X8 Chronometer, The World’s First Titanium Watch

Titanium has become ubiquitous in modern watchmaking, and with good reason. It’s a nearly ideal material for watch cases; in general it has a higher strength-to-weight ratio than steel, making it more comfortable to wear (especially in larger watches) and it’s hypoallergenic, which is a big plus for anyone with a contact allergy to the nickel found in stainless steels. It’s also highly resistant to corrosion (titanium naturally forms a layer of surface oxides, which prevents any further oxidation of the bulk metal). It is, however, more difficult to machine than steel; titanium conducts heat poorly, which means temperature during machining has to be carefully controlled, and titanium also has a tendency to gall – that is, it tends to build up on the cutting edges of machine tools. It’s also very difficult to produce a consumer-ready, polished surface, and titanium is also softer than steel and unless it’s given a surface hardening treatment, it scratches much more easily than stainless steel. For all of these reasons, titanium became a commonly used metal for watch cases only gradually, and fairly late in the history of watchmaking – the first watch with a titanium case didn’t appear until 1970, when Citizen launched the X8 Chronometer.

The X8 Chronometer in titanium was part of the series of X8 watches, which were originally introduced in 1966, and which used a movement that was a sort of intermediate step between mechanical and quartz watches. The X8 watches, which variously said, “Electronic Watch,” “Chrono Master,” and “Cosmotron” on the dials (later versions would drop the X8 label entirely) were all powered by electronic movements with balances impulsed by magnetic coils. This technology had been introduced for the first time by Hamilton, in 1957, in the Hamilton Electric 500, and such watches were part of the exploration which took place across the watch industry, up until the mid-1970s, of alternatives to purely mechanical timekeepers, which included tuning fork movements like the Bulova Accutron (Citizen produced its own tuning fork watches under license from Bulova, but manufactured in Japan, called the Hisonic watches) electric watches with balance wheels, and hybrid quartz-tuning fork watches as well. (The Accutron tuning fork movement was recently relaunched as the Accutron 314).

The X8/Chronomaster/Cosmotron watches probably pushed the electronic watch concept as far as it could go. The movements first ran at 18,000 vph, but Citizen would eventually run them at frequencies as high as 43,200 vph, and several versions, including the titanium model, were certified as chronometers by the Japan Chronometer Inspection Institute (the last Citizen watch to be so certified).

According to Citizen, the X8 titanium chronometer was made in less than 2000 examples and it was only produced from 1970 through 1971, which perhaps speaks to the expense involved in producing a titanium watch case. It was one of the more expensive watches in Citizen’s catalog, priced at JPY 45,000 (about $420 at the time; in 1970 the average US family income was $9870). The X8 name reflected the space-age identity of the watch: X for the unknown, and 8 for infinity (the symbol for infinity is ∞).

Titanium was certainly the metal of the future in the 1960s and 1970s. Its lightness, strength, and resistance to corrosion made it indispensable in the aerospace industry. Titanium was also used in cutting edge military applications. The Soviet Union made attack submarines with high strength titanium hulls – the Alfa class, designed as a deep diving interceptor, could hit speeds of almost 50mph submerged, and the United States used titanium for its A12 and SR-71 reconnaissance aircraft, which still hold the record for the fastest air-breathing aircraft ever flown.

In 2020, for the 50th anniversary of titanium at Citizen, the New York Times spoke to Norio Takeuchi, Citizen’s managing director for watches:

“Citizen introduced what it called the world’s first titanium watch in 1970, the year after the first moon landing, although executives said the watchmaker had considered using titanium for some time. ‘We wanted a watch that everyone can wear, every day, comfortably. We were looking for the best material possible to go on their wrist,’ Mr. Takeuchi said. ‘Back then, it was during the space development with the first Apollo landing on the moon. And one of the materials used on the spacecraft was titanium.'”

Titanium is expensive and difficult to refine, compared to iron and steel; the extraction process is known as the Kroll process and while it was invented by William Justice Kroll in 1932, it was not until 1940 that he had tweaked the process enough for it to become commercially viable. The cost of refining and purifying titanium, combined with the fact that it is more difficult to machine than steel, kept it from being used at scale until the 1960s, when it rapidly became the standard for airframes in commercial aviation, especially in structural components as well as engine components where high strength and light weight were essential.

At the time the X8 debuted, it was not practical to produce a high gloss finish on titanium consumer products, so the X8 has a grey matte finish which is fairly close in color and texture to pure titanium sponge. Titanium sponge is the first step in titanium refining in which pure titanium results during the Kroll process. The case of the X8 was almost pure titanium – 99.6% titanium according to Citizen – and it has a texture which doesn’t feel all that far removed from titanium in its raw form.

Today, Citizen’s use of titanium relies on its Duratect surface hardening technology, which can be produced in a wide range of colors and in highly polished finishes which were impossible in 1970. This process addresses the single biggest problem with titanium as a material for watch cases, which is that untreated titanium is soft and scratches easily; an image from Citizen showing a simulated ten year wear test on Duratect treated titanium vs. untreated titanium shows the dramatic difference the Duratect process makes.

The Duratect process produces what Citizen calls Super Titanium, which can even be used in conjunction with titanium (Citizen has recently released the Atessa Platinum Shine collection).

There is a certain almost Brutalist charm to the original X8 Chronometer, though. With its matte finish case and hybrid movement, it marks a moment in the history of horology where everything was on the table. Only a year before it debuted, the first quartz watches had been released; Accutron, which had been introduced just ten years before, had made tuning fork watches the new gold standard for wristwatch precision, albeit briefly, and the X8 itself was the first of a new wave of watch case materials which would finally break the centuries-long tradition of using gold, platinum, or steel, and make a range of new approaches to casemaking possible which would have been unimaginable just a few years before. It’s a modest enough piece to look at, perhaps, but it’s also a physical reminder of a year when the world of watches stood on the brink of transitions that would change it forever.