Why Do I Need an Anti-Magnetic Watch?

Nowadays, magnets are everywhere. They’re in virtually all of your electronic devices, including smartphones, tablets, laptops, and so on. Magnets can also be found in purse clasps, refrigerators, guitar pickups, speakers, hairdryers, and all manner of other everyday objects, making the world a veritable minefield of potential magnetic danger to the timekeeping precision of your watch. In the words of Colonel Kurtz, “The horror! The horror!” 

So how do magnets affect mechanical watches? To begin with, many of the components that comprise the movements of watches are made from metals of various sorts. You might be surprised to learn that a lot of the metal used to construct watch movements isn't susceptible to magnetization. But ferrous metals, that is, metals that contain iron, are very likely to fall victim to magnetization, and there are many key parts of a movement that belong to this category.

The component that is perhaps the most likely to succumb to magnetization, and what is arguably the most crucial for your watch to keep precise time, is the hairspring.

If your watch is unfortunate enough to cross paths with a relatively powerful magnet, the coils of the hairspring may bunch together, become self-attracted, or otherwise distorted to such an extent that the regulation of the beat rate of the watch becomes less and less accurate. This can cause your watch to run fast or slow depending on how magnetization has affected the hairspring. 

Your watch can encounter magnets in all sorts of settings. Imagine, for example, that you’re on an international flight to Geneva to attend Watches & Wonders. You’re trying to get some work done on the plane, and you feel like your wrist might need to breathe a bit while you’re typing away on your laptop. You set your watch down on top of your phone that’s positioned right next to your computer on the fold-out tray. Half-an-hour later, when you decide to strap your watch back onto your wrist, you discover that it’s running several minutes fast! What to do?

If you’re traveling to Geneva, you should have no trouble finding a capable watchmaker who can demagnetize your watch in no time. If, however, you’re stateside, and your Oak & Oscar watch needs fixing, simply fill out the service form that can be found on our website, send your watch to us, and our watchmaker, Nathan Bobinchak, can take care of it no less adeptly than anyone in Switzerland. 

Of course, there are ways to avoid finding yourself in this situation altogether. Apart from never leaving your house (though,as should be clear at this point, even that wouldn’t guarantee that your watch would escape the ill effects of magnetization), the most straightforward option would be to purchase a watch that is more or less impervious to the effects of magnets.

Now, how does a watch achieve the Herculean feat of slaying the magnetic fields that surround us at each and every turn? There are a couple ways in which modern watches combat magnetization. One way is to fashion the escapement from silicon components. Silicon is naturally resistant to magnetization and so is ideal for use in watch movements. Another, more traditional approach, is to use an iron plate along the lines of a Faraday cage. The iron cage surrounds the watch movement and shields its components from harmful magnetic fields. In similar fashion to a lightning rod, the iron shield effectively redistributes the magnetic field throughout the structure of the watch thereby diverting it away from the movement itself. Science is pretty cool, right!? 

This is the approach taken in the construction of the Oak & Oscar Humboldt GMT. The Sellita SW330 that powers the watch’s dual time zone functionality is covered by an iron plate and cage that are reinforced by the watch’s closed caseback. This allows the Humboldt GMT to resist a substantial gauss–the unit of measure of magnetic fields–more than enough to withstand any standard magnet you might encounter. Unless, of course, you stick it in an MRI scanner…you probably shouldn’t do that. And there you have it! Everything you’d ever want to know about magnetism and how it affects your watch–unless, of course, it’s a Humboldt GMT!