Tantalum is a hard, heavy, bluish-grey metal and a chemical element, symbol Ta. It resists corrosion very well. It turns up now and then in watches. The properties that make it attractive in a finished watch also make it very hard to machine.
Why is tantalum used in watches?
A thin layer of oxide forms on the surface of the metal. It gives tantalum its typical dark grey look, with a hint of blue. The metal is also very hard. It is about four times as hard as stainless steel, and over twice as hard as grade 5 titanium. It resists corrosion very well, and it is heavy. The catch comes in the workshop. The same properties that suit a finished watch make tantalum very hard to machine.
Which watches have been made in tantalum?
Audemars Piguet is said to have made the first tantalum wristwatch, in the 1980s. In 1988 it launched its first full-production tantalum Royal Oak models. A year later, Jaeger-LeCoultre showed a tantalum watch, the Odysseus Chronograph, at the 1989 Basel Fair. In 1993 the Omega Seamaster Diver 300M Chronograph took the metal to a wider audience. Tantalum also turns up now and then in watches from F. P. Journe, Hublot, Montblanc and Panerai.
Where it comes from
Anders Ekeberg discovered tantalum in Sweden in 1802. He found it while studying two mineral samples. Ekeberg could not get the new metal to dissolve in acid. For that reason the element takes its name from Tantalus, a figure from Greek myth. Tantalum has the atomic number 73. It melts at a very high temperature, 3,017°C. It is ductile, which means it can be stretched and bent without breaking. It also conducts heat and electricity well.
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