“Oh, is that a Rolex model with the parachrom hairspring?” It’s something I’ve said on several occasions, but I’ll let you in on a little secret. All I knew was that it was blue, and it was critical for regulating the beat of the watch. If you’re in the same boat, here is your 3 minute tutorial on a Rolex Parachrom Bleu Hairspring.
The critical mechanical task of a watch movement is converting the rotational energy of the wound-up mainspring into an accurate, repeatable beat that is used to drive the hands. When the escapement pushes the balance wheel (pictured in gold below), the hairspring (pictured in blue) absorbs the energy by winding up, and then returns the balance wheel to its initial position. One can think of this oscillating movement as the swinging pendulum of a clock. Performing this action both clockwise and counterclockwise, a typical watch movement could perform this action 28,800 times per hour.
In practice, the hairspring is a bit of a challenge. It is difficult to manufacture, very delicate, and easily affected by magnetism and physical impact. The tolerances allowed when producing a hairspring are generally under 0.1 micron, or 0.001 millimeters. Owing to that complexity, nearly all hairsprings within the world of modern Swiss watchmaking were made by a single provider, Nivarox.
Author setting the balance wheel and hairspring into a movement during anHSNY Watchmaking Course
It was not until the early 2000s that Rolex started to gain independence in hairspring manufacturing when they released the fruit of a 5-year development process: The Parachrom Bleu hairspring.
Most modern hairsprings at the time were made of a stainless steel that is rich chromium, nickel, and cobalt. Elements such as beryllium and titanium were added in smaller amounts. Parachrom largely avoids those materials and is driven by two key components: niobium and zirconium. Niobium, a material known for its high heat and wear resistance, makes up roughly 85% of the hairspring construction. This combination is paramagnetic, meaning that it is largely immune from then concerns related to magnetism affecting nearly all other hairsprings in existence. As an additional benefit, Rolex claims that this patented alloy is much less sensitive to temperature fluctuation than more common hairspring allows, as well as offering greater shock resistance.
As for its distinctive blue color, it is the reaction of this metal alloy with oxygen that gives the hairspring its distinctive appearance.
For all of the fanfare surrounding the Parachrom Bleu, the next generation of hairsprings are already starting to arrive from Rolex. 2014 marked the arrival of Syloxi, the proprietary Rolex silicon hairspring. While used in only a few movements, notably Rolex ladies’ references, Syloxi further improves on many of the characteristics found in Parachrom - notably anti-magnetism, resistance to shock, and long-term durability.
Speaking of the notability of blue in watchmaking, Rolex declares “Historically, the unique blue color of the hairspring has been a sign of prestige reserved for only the most accurate timepieces.” Despite the fact that the wearer will never see the blue oxide hue of their hairspring, Everest offers a few opportunities for Rolex owners to add atouch of blue to their wrist or when traveling with their watch.