Everything You Need to Know about the Impact of Magnetism on Watches

When science brought more magnetic devices into people’s lives in the 1880s and 1890s, these fields started to have an effect on watches. As a result, watchmakers experimented with various hairspring materials to make that vulnerable component more reliable.

While I may not have a background in physics, I can certainly share my personal experiences with how magnetic fields impact watches – when they actually do, that is.

Additionally, we reached out to experienced watchmakers to gain valuable insights into their encounters with magnetism.

Magnets and watches don’t get along

That’s because of their effect on the hairspring, mostly. A hairspring made of ferromagnetic material will – when magnetized – have its coil tightened or even become stuck together, causing the watch to run fast. Depending on how strong the field was and how magnetically susceptible the hairspring material is, this could result in an increase in the daily rate from seconds to quarters.

Occasionally, the mainspring will also become magnetized – and the performance of the mainspring greatly impacts the movement. Some think a watch is magnetized when it actually has a set mainspring, which reduces its amplitude dramatically. This also causes a watch to run wildly fast.

Demagnetizing – standard procedure

Most, if not all, watch manufacturers demagnetize both the watch parts and the part trays as a standard procedure during a service performed by an authorized service center or on-site by the manufacturer.

Just in case, the watch is also demagnetized prior to being regulated. A sensible precaution. It’s better to be safe than sorry, even if the watch isn’t magnetized.

Of course, it’s not uncommon for manufacturers to demonize the threat of magnetizing your watch since innovations in resistance to this particular threat to watches are a major selling point. Take Nivachron, Silicium, Si14, and Parachrom, for example.

Can magnetism stop your watch?

Technically, it’s nearly impossible. It can make it run wildly fast or – in the case of quartz – go completely haywire. However…stop it? No, not really.

This would mean going way beyond the usual limits. Perhaps if you put a 1930s piece into an MRI machine. If you’re able to try this out in real life, please share your experience in the comments.

So, stop the watch – no. Make it completely useless until it’s demagnetized – absolutely.

Vintage

Tissot shouted “first!” in 1930, when they introduced the Antimagnetique. They weren’t the first company to make a watch with a hairspring alloy with a significantly reduced sensitivity to magnetic fields. However, they were the first to take it from a prototype or small batch level to mass production.

Claims of durability written on the cases and dials of untold thousands of pieces are to be taken with a grain of salt. Still, most watches are capable of far more than we give them credit for.

At my new job, I received a laptop that has a magnetic lock. Numerous items that pass through the office contain magnets, such as magnetic strips in foldover lid packaging. Magnetic fields are also generated by hi-tech equipment, but I’m not too close to it when it’s being tested. You can find stuff like that everywhere these days.

I wore a new addition to my watch collection the day I started work – an Omega CK 2537-4 with the cal.283. The cal.283 is a sweep second version of the cal.30T2 PC AM, 30T2 SC PC AM, only under new nomenclature introduced by the end of the 1940s. The movements featured an overcoil hairspring made from an alloy with enhanced antimagnetic properties, which placed them above the rest of the 30T2/2XX family and below the RG chronometers.

So, has the calibre 283 been affected? Nope. It runs just as before, with no noticeable change in accuracy.

The vintage watches I wore to work – most notably the Luftwaffe-issued Doxa and the Nitella Datomatic – remained completely unaffected. It should be noted that their movements are of significantly lower quality than the Omega cal.283.

The majority of watches identified as magnetized by watchmakers when they land on their workbench for a service or repair are vintage pieces. So, it’s best to be more cautious with vintage pieces.

You wouldn’t need to be concerned about watches such as the Omega Railmaster, Rolex Milgauss, IWC Ingenieur, or Patek Philippe Amagnetic, which have a soft metal Faraday cage. However, there are magnetic fields in daily life that could affect them.

Apparently, a Speedmaster went haywire when it came into contact with a construction material supermarket’s tape-escalator with magnetic locks for securing shopping carts. Speedmasters have movement covers, so I’d imagine that the Ingenieur watch, ref.666, would also be affected.

Over time, advancements in hairspring alloy composition have largely reduced the effect of magnetic fields on watches. However, keep in mind that a movement consists of much more parts that are subject to magnetism than just the hairspring. This obviously involves ferromagnetic materials. Even if the hairspring is made up entirely of silicon, which is an amagnetic metalloid, the bridges, pinions, wheel train, and mainspring…all of those things could still be affected.

It’s best to be careful with watches made before 1930 and with lower-grade movements. Even rudimentary resistance to magnetic fields was almost always a selling point in the 1940s, but I wouldn’t put too much faith in pin-lever wonders. In general, hairsprings are made of alloys, which are less prone to magnetism than most common metals containing only one element.

Bottom line, they won’t behave like iron filings, but you should take some extra precautions.

Modern

Using metals such as Glucydur or Nivarox, and now more advanced materials – Nivachron and others – few modern watches show any signs of being magnetized. The magnetic fields you encounter at home, in your car, or at the office aren’t strong enough to magnetize the parts of your watch.

Seiko is one brand – in terms of modern pieces – whose products seem more likely to show signs of magnetization. Many of them use a SPRON100 alloy composed of cobalt and nickel, such as the 4R3X-series and 7S26. Higher ranges – from ordinary Seiko 6R-series to Grand Seiko-exclusive movements use a SPRON510 alloy.

While Seiko’s movements are hard to wear down, they aren’t constantly advancing in material, as indicated in the fact that Seiko was singled out by the watchmakers we surveyed as a brand whose watches were particularly often exhibited with noticeable magnetic effects.

I’ve seen some claims that modern ETA 2824s and 2892s are affected by loudspeakers or iPad SmartCovers. However, having worn a watch with an Elabore-grade 2824 in close proximity to all these supposedly clear and present dangers, I must call baloney on that claim.

289X-family movements in executions from Standard to Top also seemed unmoved by laptop mag-locks, fridge doors, iPad mag covers, smartphones, car stereos… Never heard that of the Sellita clones of ETA movements either. Neither about movements from any other ebaucherie.

In all honesty, if any of these were magnetized, you’d need to find a culprit emitting a way stronger magnetic field than your home appliances and electronics. My experience is that Omega 30T2 PC AM and 283, both from the 1940s, are absolutely unaffected by the magnetic fields I encounter on a daily basis.

The same goes for the modern Seiko 7S26 and NH35 (unbranded 4R35). Nada, they just won’t start malfunctioning.

So why get an uber-antimagnetic watch?

Good question. Frankly, you don’t need one.

Most modern watches are more than capable of handling most magnetic fields you may encounter in daily life. If you work on radar installations, or with high-powered industrial electromagnets, such as at a scrap yard, or around an MRI machine at a hospital, you probably won’t wear a watch at all. Sure, it’s cool to know that your watch can withstand extremes.

I enjoy having the extra degree of safety of timekeeping in my Longines Spirit with its Silicium hairspring.

Do I need it? No, not really. The stereo, the fridge, and the mag-lock of my laptop did nothing, not even to my Seiko SNXS79 with its outdated cal.7S26.

All in all

Being careful never hurts. Being cautious and being paranoid, however, are completely different things.

If you want to, you can buy a degausser for the sake of demagnetizing your watches yourself. However, your watch is probably capable of more than you give it credit for.

Enjoy your watch and trust the engineering and science behind it. In the words of Bobby McFerrin, “don’t worry, be happy.”.

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Do you have some experience with a magnetized watch? Let me know in the comments below.