Watch Materials: The Evolution of the Movement

Watches are intricate little machines. Their dozens of parts work in harmony, allowing them to perform an array of functions or simply tell time. In the early centuries of watchmaking, each element of these mechanical marvels had to be painstakingly crafted by hand. Elite members of society who could afford the cost of labor and parts to create a bespoke piece commissioned watches.

The Industrial Revolution began changing the scope of production across industries. By the mid-1800’s, watchmaking had started to evolve, and watches started to become more accessible to a wider scope of people. In addition to advancements in manufacturing, the development of watch materials contributed to the mass production of watches. One of the key advancements was in the creation of the most complex component of the watch: the movement.

The Main Components of a Watch Movement

Six key parts comprise a standard mechanical movement: the mainspring, gear train, escapement, balance wheel, dial train, and jewels. Originally, watchmakers used precious metals and natural jewels to make the movement. You can quickly understand why the value of these early timepieces was so high and saw limited production! Metal continued to be the material of choice for most of the components for centuries. And, in 1902, French chemist Auguste Verneuil developed a process to make synthetic jewels. It’s just been within the last decade that alternatives to metal components have developed for the movement.

Let’s take a deeper look at how these components of the movement have developed over the years, starting with the power source: the mainspring. The mainspring is a thin metal ribbon that’s curled into a spiral. Initially steel comprised the component. In early watches, the quality of the mainspring was highly variable because the techniques need to make steel with uniform composition and mechanical properties were not yet developed.

As the methods of melting and forming steel improved, carbon steel, an alloy of iron with a small percentage of carbon, comprised mainsprings. Watchmakers then formed the material into a ribbon – hardened, tempered, and coiled. The downside to carbon steel is that it can be very brittle and break easily. Yet, it saw use for many years, until the mid-twentieth century.

In the 1940’s, alloy mainsprings came into development, first by the American watch manufacturer Elgin. They called this new metal “Elgiloy,” and it was comprised of cobalt, chromium, nickel, iron, molybdenum and manganese. It was rust and corrosion resistant and strong and durable without being brittle. Over the next two decades, carbon steel mainsprings went out of production.

Other Metal Components

The other traditionally metal components of the movement—the gear train, escapement, balance wheel, and dial train—experienced a similar evolution. Steel or brass comprised the early versions of this mechanism. Like the mainspring, they were highly susceptible to the elements, like temperature change and moisture. Once again, new alloys came to the rescue. In fact, some came earlier than the development of the new alloy for the mainspring. For example, in 1896, Swiss physicist Charles Eduard Guillaume won the Nobel Prize for the invention of the alloys Invar and Elinvar. These materials replaced the use of steel in the balance wheel.

The components of the movement arguably came a long way from the early days of steel to the development of more robust metal alloys. But today, metal is becoming outdated all together. Silicon is now the up and coming material for components of the movement.

Silicon parts began to appear in watch movements in 2001, and Ulysse Nardin was the first to do so. Over fifteen years later, most manufacturers are now incorporating silicon into their watch movements. Silicon is even more resistant to elemental changes like temperature, plus it’s lightweight, completely antimagnetic, and requires little or no lubrication. The only drawback to silicon is similar to the problem with carbon steel—it has the potential to become brittle and break over time. However, modern watchmakers are already working on a solution. Bonding silicon with a synthetic diamond or carbon coating can reduce its instability.

With the development of new materials across industries, there’s no telling what might be the next big innovation for watches. For those who may consider watchmaking an old or antiquated art form, think again. It’s still continuing to evolve today.