Glossary · Materials
Bronze CuSn8
Definition
CuSn8 bronze is a copper alloy with 8% tin, known as marine bronze: it resists salt water and for this reason it is used for propellers and naval fittings. In watchmaking, it's the bronze of cases that change colour: it oxidises on the surface and develops a brown or green patina, different from wrist to wrist. The patina protects the metal underneath.
Frequently asked questions
What is BRONZE CuSn8?
Copper with 8% tin, the bronze of shipbuilding. In watch cases it oxidises on the surface and develops a brown or green patina that protects it. Each case ages in its own way.
Does the bronze stain the strap or the skin of the wrist?
The case can leave a green mark on the wrist and on the back of the strap, especially with sweat: it's copper oxide, harmless and washable. For this reason, many bronze watches have a steel or titanium case back. A vegetable-tanned lining holds up better than a chrome-tanned one.
How do I match a strap to a CuSn8 bronze case?
I encounter bronze in the case and the buckle, not at the workbench: I work the leather. Bronze calls for leathers that age alongside it: vegetable-tanned calfskin, tan leather, nubuck in tobacco, olive and blue tones. A bronze or burnished steel buckle; a polished one would clash.
The next step
The right strap isn't chosen. It is built, together.
From the atelier appointment to delivery, every step is made for those who know that things done well take time. Rare leathers, one piece at a time, eighteen months of warranty.
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