Nivaflex is an alloy used in watchmaking, mostly to make the mainspring. Most mainsprings made today use it. It resists corrosion and is very elastic. It is not magnetic at all, and it expands very little when its temperature changes.
What is Nivaflex made of?
By weight, Nivaflex is mostly cobalt, at 45%. Nickel and chromium come next. Small amounts of iron, tungsten, molybdenum, titanium and beryllium make up the rest. It is often described simply as an alloy of cobalt and nickel with small traces of beryllium and other elements. Iron is only a minor part of the mix, which sets it apart from the iron and steel springs it replaced.
Why is Nivaflex used for mainsprings?
Before Nivaflex, mainsprings were made of iron or steel. These rusted, and they were not elastic enough. Nivaflex deals with both problems. It also has a high yield strength. This means the spring can be wound up tightly without being permanently bent out of shape. Nivaflex mainsprings are sold as parts for both wristwatches and pocket watches.
Where it comes from
Reinhard Straumann, a metallurgist from Switzerland, created the Nivaflex mainspring material and patented it in 1948. In 1951 he set up a company, Nivaflex SA, to make commercial use of it. He registered the Nivaflex name as a trademark in 1957. The material came first. The company followed three years later, and the trademark six years after that.
Not to be confused with
Nivarox is an earlier alloy from the same inventor, Reinhard Straumann. The names are close, and both alloys are used for springs inside a watch. But they are different materials with different jobs. Nivarox is used for hairsprings, not mainsprings. Nivaflex is used for mainsprings. Nivarox came first, and Nivaflex came later.
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