On my countless trips around Switzerland to meet artisan watchmakers and craftsmen, I have seen machines that do things you would not believe.
I find this one fascinating. This mechanical beauty removes 0.005mm from the surface of this minute metal pin that goes into a ruby in the movement to turn the balance wheel. This operation is called ‘roulage’ and is very delicate. It is done in an isolated and quiet area of the workshop, because the craftsman in charge has learned by experience with hearing to know if the exact and correct amount of material has been shaved off, in order for the movement to work properly. Here under the microscope, you can see the before (left) and after (right).
And this is just one part. There are so many details in a timepiece that are made by specialist artisans with their skills passed through generations. It is rare to find this level of craftsmanship in other industries.
Artisans of Watchmaking