How to Demagnetize A Watch

Since their invention hundreds of years ago, watches and other timekeepers have had one consistent and implacable foe: magnetism. Magnetic fields are the arch-enemy of a watch’s ability to run reliably and accurately, as they can adversely affect the tiny metal parts in a traditional mechanical movement like the wheels, gears, and hairspring. The ill effects of magnetic fields on watches’ reliability first emerged as early as the 1920s, when electrical power became more ubiquitous in both homes and businesses, and the challenges for watchmakers have only multiplied in the years since. 

Today, we’re surrounded by magnetic fields in almost every area of our everyday lives, from microwave ovens and refrigerators to computers, cell phones, and electrical motors. The watch industry’s decades-long battle against magnetic fields, explored in greater detail in this article, has been a largely successful one, with the use of protective inner cages and non-ferrous movement components now commonplace. Omega, for example, makes watches with movements that can resist magnetism up to 15,000 gauss, as in the Railmaster watch shown above. However, most of us, at one time or another, have still experienced a situation in which a watch falls victim to being magnetized, and it can be a bit intimidating to figure out how to fix it.

[toc-section heading="How to Tell if Your Watch is Magnetized"]

A watch that has had its movement magnetized might be difficult to notice at first. It might run slower or faster over a sustained period, gaining or losing time consistently. The watch might even stop entirely ahead of its power reserve running down. Running fast, i.e., gaining time too quickly, is the most likely outcome, as the magnetic field’s primary effect is on the hairspring, which is the coiled metal spiral that controls the impulses to the balance wheel. When exposed to magnetism, the hairspring’s coils will stick together, resulting in the balance wheel, and by extension the watch’s hands, moving too rapidly. (Again, some watch brands have headed off this potential problem by developing hairsprings made of antimagnetic materials, like Rolex's blue Parachrom hairspring, below).

The quick and easy way to determine whether your watch has actually been magnetized is to place a compass (or a smart phone with a compass app, which is probably more likely for most of us to have within easy reach these days) next to it on a flat surface. You could even use an electronic watch with a built-in compass, like some models from Garmin or Casio. Move the watch slowly closer to the compass and pay attention to the latter’s needle: If it moves out of position and points toward the direction of the timepiece, congratulations — you have a watch with a magnetized movement.

(At this point, some might be thinking of an obvious follow-up question: What about a watch with a quartz movement (like the Seiko Astron above)? Can that fall prey to magnetism as well, despite the fact that its timekeeping is governed by a battery rather than a mechanical oscillator? The short answer is yes, because magnetism can affect the tiny step motors inside the movement that move the watch’s hands. But the effect is usually temporary, and the watch’s running should return to normal once the source of the magnetism is removed.) 

[toc-section heading="How to Demagnetize Your Watch"]

Of course, as with just about any other problem incurred by a watch owner — a scratched or shattered crystal, a date wheel that won’t advance, a battery replacement for a quartz watch — you can opt to let a professional handle it. If you have a trusted local watch repairer, he or she can take care of the issue with a minimum of fuss and probably at a minimal cost. But if you’re more apt to take the DIY approach — and that’s why you’re reading this, right? — demagnetizing a watch requires little more than the purchase of a small device and a simple set of instructions. 

The tool you’ll need is a watch demagnetizer, a small, simple device that generates an alternating magnetic field to remove the built-up magnetism in a mechanical watch movement. You can find these devices at online retailers like WalMart, Etsy, Temu, and eBay, generally priced around $15 - $20 or even a bit less. How it works is simple. First, you need to make sure that the watch you’re about to demagnetize is not currently running. If its movement is equipped with a hacking seconds function, pull out the crown so that the seconds hand stops. If it doesn’t have this functionality, you’ll have to let the power reserve run down naturally before performing the operation.

Once the watch is safely “asleep,” either place it, dial-side down, on the demagnetizer’s smooth pad or hold it in your hand just slightly above the pad. With your other hand, press the button with your index finger and hold it down. Then, still steadily holding the watch over the pad, slowly bring it up and away from the device while keeping the button held down. After about a foot (or about 30 centimeters) of elevation, you should be able to release the demagnetizer’s button and place the watch back down on a flat surface (not the demagnetizer itself, as you don’t want to subject it to magnetism all over again). The whole process should take about a minute or less. Afterward, of course, you’ll want to test the watch again with a compass or compass app to ensure that the demagnetization has been successful. And don’t forget to reset the time on it if necessary. 

[toc-section heading="How to Prevent Your Watch from Being Magnetized Again"]

As simple as we’ve now learned it is to demagnetize a watch, you’ll want to take a few easy steps that will help make it unnecessary in the future.  Store your watches a respectable distance away from wireless electronic devices like smartphones and Bluetooth speakers. Don’t place them in the proximity of magnets or wireless devices like chargers that emit magnetic fields. And of course, as a matter of course, it’s best to keep watches wound on a regular basis so you can keep tabs on how they are running. The main thing to keep in mind if you have a magnetized watch is not to panic. Magnetism won’t wreak any lasting damage on the watch or movement and, as we’ve seen, its effects can be reversed quickly and rather easily. Let’s just call it the horological law of attraction.