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One of the most iconic material for a watch is definitely the Stainless steel used essentially in the watch case and the watch bracelet. Most of people know what is Stainless steel about, but did you know that there are several different types of steel used in watch-making? How Watchmakes came to use Stainless Steel and how different is one from another?
Stainless Steel

Stainless steel, an amazing invention, as well as a great mistake

Some inventions are planned, others happen by chance. When in 1913 Harley Brearley was trying to improve the resistance of gun barrels, he would not imagine that his work would change the way we would use steel in the 20th century and beyond.
He was working at that time for Firth Research Laboratories in the UK. He came up with the idea that if he would make an alloy of steel and a certain quantity of chromium above 5% (usually quantity for that time), he could probably improve resistance. Despite the fact his work was never really taken in consideration at the end, he realized that essay N.1008 had an amazing resistance to corrosion and also would not rust in atmosphere. He thought at that time that it would be an interesting application to cutlery and precious instruments like for Surgery.
The alloy was improved by Firth Laboratories thanks to the addition of Nickel. Unfortunately for the company, this technique was not patented in the UK, so anyone could produce their own stainless steel.
In 1924, Firth decided to commercialize Stainless steel and in 1930, Thomas Firth & Sons merged becoming Firth Brown Steels.

Stainless Steel to the rescue!

How Stainless steel arrived in watch-making? Well, it came just in time! In the beginning of the 20th century, Swiss watchmaking used precious metals like Gold and Silver to produce watch cases. They were easy to manually manufacture, flexible to shape and still hard to resist time. Of course at that time it was important to have a precious metal as the watch was considered as a social status symbol and somehow the jewelry side for men. Most of these watches were pocket watches so well protected from outside conditions. In 1929, the world was hit by its first global economic crisis (Wall Street crack) and fortunes of one day became bankruptcy in the other. People did not have any money left and loads of debts. So everybody started melting their gold and silver watch cases to pay their bills. Before 1929, more than 50% of all exported Swiss Watches were made in Precious metals. In 1930 this number was reduced to 30% and in 1935 only 5% were made in Gold and Silver. There was a huge demand for cheaper watches and Swiss Watchmakers had to find a solution. By that time, Stainless Steel was getting very popular throughout Europe as Firth Brown Steel started exporting it. It was a cheap yet resistant material that would allow Watchmakers to shape watch cases again as well as bracelets (which arrived later in history).
Stainless steel watch case
The only problem is that Stainless Steel is harder to work than Gold, Silver or even Platinum. The traditional methods would not work. Thanks to the cheap cost difference, companies started industrializing themselves with machinery capable of handling the new material. For some of them, it also allowed to increase the number of units produced, introducing a certain idea of industrialization in a very hand-crafted environment.

Stainless steel, which one is the best? It depends


Stainless Steel is cheaper than Gold or Platinum. We know that. Nevertheless, the material used in watches need to “survive” certain conditions of corrosion, usage and resistance. Different types of metal were used overtime. Today there is a very strong debate between Stainless Steel 316L and 904L.
The first one, 316L, has a very strong track record in marine purposes. Most of the metal parts in a boat or in diving equipment is done with 316L. Watchmakers started using it quite widely as it has a good resistance to corrosion, scratch resistant and it is antimagnetic. Dive watches usually have a case and bracelet in Stainless steel in order to prevent any damage from the salty sea water and the outdoor conditions. This Steel is the one most predominant in the Watchmaking industry. Of course there are always exceptions. One of them is the usage of the 904L, specially by Rolex.
904L is traditionally used in certain industrial fields where the environment is pretty corrosive and the usage of Acid is common. 904L has a stronger resistance in this field of activity but what about watchmaking? Unless you wash your hands regularly with Acid, why 904L would be a better choice. According to certain tests, we know 904L is stronger than 316L, therefore it is also harder to shape. This hardness allows a more longterm polish that remains perfect for several generations. From a aesthetics point of view, 904L has also a slightly different grey color than 316L which might be of taste of certain buyers.
Stainless steel 904L

Rolex GMT Master
Being a much harder material to handle, Rolex developed its own tools, and a 250 tons press was installed in the Rolex factory to stamp the watch cases. Here is a video made by Rolex about the 904L Stainless Steel.

As we can see, Stainless Steel was invented almost by mistake and since then, it was introduced in many ways in our lives. Everyday we use Stainless Steel. The knives, forks or spoons we use at every meal, buttons, machinery, doors handles, belt bucklers, automobile, home furniture and of course watches. Stainless Steel is in a way a very precious metal for all of us.


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