Is Your Watch Magnetized? Signs, Causes and Fixes

A watch that kept steady time for months and then, within a week, starts gaining several minutes a day has usually not broken. Very often it has spent an evening lying on a magnetic phone case or next to a laptop speaker. The good news is that magnetism is one of the cheapest and quickest watch problems to fix.

What a magnet does inside a mechanical watch

An automatic or hand-wound watch keeps time with a balance wheel that swings back and forth several times a second. Its rhythm is controlled by the hairspring, a coil of metal finer than a human hair. Traditional hairsprings are made from alloys that can pick up magnetism. When that happens, neighboring coils cling to each other. The spring behaves as if it were shorter and stiffer, the balance swings faster, and the watch gains time, sometimes a lot of it.

Other small steel parts can hold magnetism too, but the hairspring is the usual culprit. Some modern movements use silicon or special alloy hairsprings that shrug off everyday magnets, though these are mostly found in expensive watches. Be wary of the word “antimagnetic” on its own: the international standard for it tests at a fairly modest field, and a strong magnet held right against the case can still affect a watch that passed.

Quartz watches

Quartz is a different story. The hands on an analog quartz watch are driven by a tiny stepping motor that contains a magnet of its own. A strong field nearby can stall or upset that motor while the magnet is present. Take the magnet away and the watch normally carries on as before, with no lasting effect. Whatever time it lost while stalled stays lost, so reset it (How to Set the Time and Date covers the safe order). If you are not sure which kind you own, Quartz vs Automatic Movements explains the difference.

How to tell it is magnetism

A mechanical watch that drifts by some seconds a day is behaving normally. One that suddenly gains minutes is not. The pattern matters as much as the number:

Try to remember when the trouble started. If it lines up with a new phone case, a new bag or a new spot on the nightstand, you probably have your answer.

Where the magnets are

Small, strong neodymium magnets are now built into a surprising number of everyday things. The ones that catch watches most often:

• Phones and their accessories: magnetic cases, wallets, car mounts and wireless chargers.
• Tablets and laptops: magnetic covers and keyboards, the magnets that hold a laptop lid shut, and the speakers near the keyboard.
• Speakers and headphones: almost every speaker contains a magnet, and bigger speakers usually have bigger ones.
• Bags and clothing: magnetic clasps on handbags, wallets and jackets. Some watch boxes and rolls close with magnets too.
• In the kitchen: induction cooktops, magnetic knife strips and fridge magnets.

Distance is your friend. The field from a small magnet weakens very fast as you move away: doubling the distance cuts it to roughly an eighth. A watch left lying on a magnetic phone wallet for an evening is at real risk. One on the other side of the desk is not. Keep the watch at least 5 cm (2 in) from these sources; for everyday magnets that is usually enough.

The compass test

You need nothing more than a basic magnetic compass, the kind sold for hiking.

1. Set the compass flat on a table, away from phones, laptops and any metal furniture, and let the needle settle.
2. Take the watch off and hold it a few centimeters from the compass.
3. Move it slowly around the compass, and pass the case over it from different sides.
4. Watch the needle. If it swings toward the watch or follows it as you move, something inside is magnetized.

One caution: a compass needle is a magnet itself, so it may twitch toward plain steel held right against it. A small flicker at the last millimeter means little. A clear swing from a few centimeters away is the sign you are looking for.

Fixing it: demagnetizing

A watchmaker removes magnetism with a demagnetizer, a small device that produces an alternating magnetic field. The watch is held in the field and then drawn slowly away, which leaves the magnetized parts scrambled back to neutral. The case does not need to be opened, it takes seconds, and many watchmakers will do it while you wait, for a small charge.

Home demagnetizers are also sold, usually as small boxes with a push button, and they work on the same principle. Follow the instructions closely. The usual method is to hold the watch on the device, press the button, move the watch slowly away to arm’s length and only then release the button.

Afterward, wear the watch for a day or two and compare it with your phone. If it is back to its old rate, the job is done. If it is still well off, magnetism was not the whole story, and the watch needs regulating or a service.

Keeping it from happening again

• Do not rest the watch on top of a phone, tablet or laptop, and do not stack it on a wireless charger at night.
• Take the watch off before cooking on an induction cooktop. Heat and splashes are no good for it either.
• Give it its own pocket in a bag, away from magnetic clasps and from your phone.
• When you buy a watch box or travel roll, check whether it closes with a magnet, and if it does, where the magnet sits.
• Store the watch away from speakers and electronics. A drawer or box on the other side of the room is ideal; How to Store Jewelry has more on setting one up.

Keeping the case and bracelet clean helps you spot other problems early, too; How to Clean an Iced Out Watch shows how. If a watch you bought from us is running well off and the compass test comes up clean, email [email protected] with your order number and a note of how far it is out each day.