If you’re new to watchmaking, knowing how to demagnetize a watch, when to demagnetize a watch and understanding the effects of magnetism on your watch service is absolutely critical for performing a quality service.

That’s why one of the basic requirements before adjusting the regulation is that the movement must be 100% free of magnetism and not just 80 or 90% free.

Today, we’re going to dive into magnetism, hopefully clearing up some of the confusion associated with it.  I’m going to show you the one thing that might be handicapping your watch service more than anything else.

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The Effects of Magnetism On Your Watch Movement

The Signs of Magnetism in a Watch

Magnetism and its effect on a watch movement are not always going to be visually obvious to you.

You may have heard that if a movement is magnetized, the hairspring coils are going to stick together or stick to each other. That’s not always going to be the case, as you’re going to see in a few minutes.

How exactly does Magnetism affect the normal operation of a movement?

In extreme cases, if you don’t demagnetize a watch movement, it can cause the coils of the hairspring to stick together, effectively shortening the hairspring, which will cause faster rates.

What’s far more common is that a smaller amount of magnetism is present, which is affecting the rate to a lesser degree.

This situation will cause a lesser experienced watchmaker to completely overlook the real issue affecting the rate. This can lead to troubleshooting in all the wrong places.

Testing a Movement

I’m going to be using one of my test movements today, the ETA 2824.

If you’re not familiar with this concept of test movements, these are either new or at least well-running movements that you use to test different theories, ideas and concepts. Instead of using an older movement, you just use a test movement.

Testing the Effects of Magnetism in a Watch

I’m going to begin with the movement at a full line, and we’re going to start by demagnetizing this watch movement, and we’re also going to demagnetize the movement holder.

I want to establish a benchmark by first getting a reading on the timegrapher to see where the rate and the amplitude are.

As you can see, the rate is fluctuating between three to five seconds per day, and the amplitude is currently at 231 degrees.

ETA 2824 Benchmark before Magnetism
ETA 2824 Benchmark before Magnetism

Magnetizing the ETA 2824

To magnetize the movement, I’m just going to use a magnet in a floor sweep. It has a strong magnet inside. It will be more than adequate for the testing that we’re doing right now.

With the movement back on the timegrapher, we can clearly see the results that the magnetism is having on the movement.

Results of Magnetism of Rate and Amplitude
Results of Magnetism of Rate and Amplitude

The rate has increased to between 118 to 120 seconds per day, and you’ll also notice that the amplitude has dropped to 178, which is about 53 degrees less than from where we started from.

The Magnetism Myth

A myth that lurks out there on the internet is that if you don’t demagnetize a watch, it will show up on the timegrapher as a snowy screen. You can see we in the picture above, we have a very magnetized movement, but we also have very straight trace lines.

Snow on the screen has nothing directly to do with magnetism by itself, but if you have another fault, like the clearance between two parts, the magnetism could make that problem worse, which can create disturbances to the trace lines.

Does Magnetism Make the Hairspring Stick?

When we look at the effect of magnetism to this hairspring, you can clearly see that the hairspring coils are not sticking to each other.

Non Sticking Hairspring Coils
Non Sticking Hairspring Coils

When I stop the balance wheel from spinning and take a closer look at it, I don’t see any points along the hairspring which are stuck together.

Just to make sure we’re not missing anything here, I am going to remove the balance wheel to check the area under the balance cock where we can’t see it right now.

Hairspring From Underside
Hairspring From Underside

Looking at the hairspring from the underside, it should be obvious that there are no areas of the coils that are sticking together.

 Clearly, a movement can be highly magnetized, enough to drop the amplitude 50 plus degrees, as well as speed up the rate by 115 seconds per day, with no visible signs to the hairspring itself.

Why is Magnetism Affecting the Rate

If magnetism is not shortening the hairspring by the coils being stuck together, what’s going on that’s causing the amplitude to drop and the rate to increase?

Normally, when we see rates go up like this, it’s due to a shortened hairspring, it’s caused by oil contamination, or the coils not being concentric.

It can even be cases of extreme magnetism, all of which are going to cause the hairspring stick and become shorter.

The way I would describe what we’re seeing here is what I call magnetic friction.

Magnetic Friction

This is not friction like two parts rubbing together. It’s more of a resistance or an interference of the magnetic field between the steel parts as they move past one another.

Think about when you’re holding two magnets together.  That force that you feel as they’re trying to connect to each other is the force that the escapement has to overcome.

This is magnetic friction. The result of not demagnetizing a watch.

Magnetic Frictions Effect on the Hairspring

If the movement doesn’t have a non-magnetic hairspring, when the coils move in and out from each other, this magnetic friction makes it harder for the coils to expand and contract.

This extra strain to the hairspring lowers the balance wheel’s amplitude and increases the rate.

Magnetic Frictions Effect on the Pallet Fork

The pallet fork and the pallet bridge are also made from steel. When the pallet fork is trying to move away from the banking pin, there’s added resistance, almost as if the two parts are sticking to each other.

Magnetism's effect on the Pallet Fork
Magnetism’s effect on the Pallet Fork

This of course, lowers the impulse to the escapement, which lowers the amplitude, increasing the rate.

Magnetic Frictions Effect on the Balance Pivots

The balance jewel setting is steel. When the guard pin moves back and forth across it, more power is required to overcome this resistance. This slows the balance amplitude and increases the rate.

Magnetic Frictions Effect on the Safety Roller

If you’re working on a vintage movement, which has steel safety rollers, there’s resistance between the end of the pallet fork and the roller, which lowers the balance wheel amplitude, increasing the rate.

When you start adding all these things together, you’ll start seeing rate increases like what I just showed you on our test movement.

What about Magnetism Slowing down a Rate?

I can tell you in 40 years, I’ve never seen or heard a convincing reason how this can actually happen.

A movement with a very slow rate could have some magnetism in it, but the fault that is causing the rate to be slow is just more powerful than whatever the effect the magnetism is having to the movement.

Okay so let’s put the balance back onto the movement and look at a couple ways that we can detect magnetism.

Detecting Magnetism in a Watch Movement

There are several ways this can be done.

The first is when you’re using steel tweezers and a screw sticks to it. It’s obvious at this point that something is magnetized.

The Lepsi App

Lepsi App
Lepsi App

Another way is to use an app like Lepsi, which is what I’m going to test to see how accurate this app really is.

 Once you get it set up, all you do is you find the sensor on your phone. You hold the movement right over the sensor and if it detects magnetism, it’ll say magnetism detected right on the screen.

In this case you can clearly see the app is picking up the magnetism.

Test for Magnetism with a Compass

Now another way to detect magnetism is with a compass.

Using a Compass to Detect Magnetism
Using a Compass to Detect Magnetism

With our movement on the bench, we just move the compass over it and you can clearly see that the needle is reacting to the magnetism of the steel parts.

Checking Lepsi & Compass on Demagnetized Movement

Now I’m going to demagnetize the movement again and just for good measure I’ll demagnetize the movement holder as well.

I’m going to put the movement back on the Timegrapher and look at the readings again.

Lepsi Test 1
Lepsi Test 1

Now let’s check the app and the compass again.

We start the app test by holding down the arrow button. You hold the movement over the sensor and as you can see the app is not reacting to the presence of any magnetism.

Lepsi test of no Magnetism
Lepsi test of no Magnetism
Compass No Magnetism Test
Compass No Magnetism Test

When we do the test again with the compass, there almost appears to be signs that the compass is reacting to something.

But I can tell you that this movement is completely demagnetized.

What’s more Reliable, Lepsi or a Compass

I would say that of the two methods, the app appears to be way more reliable.

This is probably partly because the needle of the compass is magnetized slightly. I think it’s merely reacting to the steel parts instead of actual magnetism in the movement.

Clearly we can see the app works, but what about when the movement is magnetized to a lesser degree?

Testing Magnetism to a Lesser Degree

I’m going to magnetize the movement again, but this time I’m holding it a little further away from the magnet to see if we can introduce a smaller amount of magnetism.

With the movement back on the Timegrapher, we can see that the movement is showing the effects of a smaller amount of magnetism.

Reading of Magnetism to a Lesser Degree
Reading of Magnetism to a Lesser Degree

The current rate of 56 to 58 seconds per day is roughly about half of what it was before. Let’s see if the app picks this smaller amount of magnetism up.

Testing the Lepsi App for a smaller Amount of Magnetism

Well clearly it does.  I would say in general that the app is reliable at this point.

Lepsi App Picking up a Smaller Amount of Magnetism
Lepsi App Picking up a Smaller Amount of Magnetism

Testing Lepsi on Very Small Amounts of Magnetism

Can you rely on it to be able to pick up magnetism that might only affect the movement by 10 or 15 seconds per day?

Well, I had to know, so I messed around with waving the movement over the magnet at different distances until I got a magnetism effect of about plus 20 seconds a day.

I checked it again and the app picked it up. So, I would say if used correctly, the Lepsi app is very reliable for detecting magnetism.

 New Watchmakers Mistake on Demagnetizing a Watch

And here lies the problem that may be confusing a lot of new watchmakers.

If you’re under the assumption that the presence of magnetism in a movement is only there when you can see the coils sticking together, or that magnetism is always going to create obviously high rates, then you’re going to run into problems with your regulation.

When looking at a timegrapher, decreased amplitude and rate increases of 10 to 20 seconds per day, magnetism can easily be overlooked as being some other issue related to the 20 or so other things that could cause low amplitude and higher rates.

Magnetism Can Hide in small Rate and Amplitude Changes

Now there will be times where you may think you’ve done a great job because the timegrapher is showing low amplitude, but your horizontal rates are zero seconds per day.

 In reality, if there’s any magnetism present, the movement is actually running at a negative 20 to 30 seconds per day.

Now I don’t know how many times I’ve said this in my videos, but the second rule of adjusting and regulation is that the movement has to be 100% free of magnetism.

This is why demagnetizing the watch should be a standard part of your service work.

When to Demagnetize a Watch

When I do my standard service, I start by demagnetizing the movement before I even start working on it, you know, while I’m doing my preliminary inspections.

I demagnetize again before I clean the parts. I do this to prevent any metallic particles that may be left over in the cleaners in the rinse from being attracted to any parts that may be magnetized.

 Then demagnetize one last time after assembly before the movement runs through its 24-hour settling in period.

Now is that overkill? I don’t really think so.

How Important is it to Demagnetize before Service Inspections

When checking the current state of a movement before you start taking it apart, how can you be sure that any problems with how the escapement is running are not caused by magnetism?

How important is it to not have metal particles on your nice clean parts after they come out of the cleaner?

How important is it to know that no static electricity or magnetized tools have caused your freshly serviced movement to become magnetized?

Testing Demagnetizers

Now there’s tons of demagnetizers on the market and you can spend silly money on one if you really want to. What’s personally important to me in the demagnetizer is reliability and speed.

I don’t want there to be any doubt about whether a movement has any magnetism in it, and I certainly don’t want to have to check it every time with an app or a compass. But that’s just me.

Elma Demagnetizer

The Elma anti-mag unit that I use, I mean they run about 260 bucks or so and even though it may seem like a lot of money, for me and as much as I use it, it’s overall reliability and ease of use.

Elma AntiMag
Elma AntiMag

From my perspective, it’s worth the money.

I use it not only to demagnetize watch movements, but I use it to demagnetize all my tools as well. I understand a lot of people are either not in the position or have no desire to spend that much.

 Lets try the demagnetizer that everyone seems to recommend. That little blue box from China.

Blue Demagnetizer
Blue Demagnetizer

Testing Generic Blue Demagnetizer

So, we’re going to start off by establishing our benchmark. In this case, we are starting off at about four to seven seconds per day.

Then I’m going to magnetize the movement again and then we’re going to verify the magnetism is present on the timegrapher.

Testing Blue Demagnetizer
Testing Blue Demagnetizer
Blue Box Magnetized Movement
Blue Box Magnetized Movement

As you can clearly see on the timegrapher, magnetism has increased the rate. Now when using this style of demagnetizer, how you use it is key.

You simply lay the movement on the top; you press and hold the button down and you should feel the movement start vibrating a little bit.

And then you slowly draw the movement away until you get about two or three feet away from it. The further the better.

As you can see, the demagnetizer worked in this test.

Blue Demagnetizer Test Results
Blue Demagnetizer Test Results

So if you don’t have a demagnetizer and you need one, this $10 demagnetizer along with the Lepsi app is a pretty good way to ensure that your movement is 100% free of magnetism.

Frequently Asked Questions

Can I demagnetize a watch at home?

Yes, it is possible to demagnetize a watch at home using a few simple methods. Magnetization can cause your watch to run fast or even stop working altogether. Here are a few ways to demagnetize a watch at home.

You can use a demagnetizer tool: This is the most effective and easiest way to demagnetize a watch. You can purchase a demagnetizer tool online an eBay or Amazon Start by holding the watch close to the demagnetizer and press the button to activate it. Slowly move the watch away from the demagnetizer. The further the better.

Use the Lepsi app to check if magnetism is still present.

It’s important to note that if your watch is not working properly after attempting to demagnetize it, you should take it to a professional watchmaker for repair.

How do you remove magnetism from a watch?

To remove magnetism from a watch, you can use a demagnetizing tool.

Hold the watch close to the demagnetizer tool and press the button to activate it. Slowly move the watch away from the demagnetizer and THEN release the button on the demagnetizer. Test for magnetism with the Lepsi App. Repeat if needed

It’s important to note that when using a demagnetizer tool or a strong magnet, you should not touch the watch’s movement directly, as it could damage the delicate components. Additionally, you should avoid exposing your watch to magnetic sources such as speakers, computer monitors, and cell phones, as they can magnetize your watch. If your watch is not working properly after attempting to demagnetize it, you should take it to a professional watchmaker for repair.

How do you tell if your watch is magnetized

If your watch is magnetized, you may notice some of the following symptoms:

Inaccurate timekeeping: A magnetized watch may start running too fast, sometimes by several minutes or even hours per day.

Erratic movement: A magnetized watch may show erratic movement or stop working altogether.

Strange noises: A magnetized watch may make ticking noises that are louder or faster than usual.

Other electronic devices are affected: If other electronic devices, such as your cell phone or computer, are affected by the same magnetic field that your watch was exposed to, it’s likely that your watch is magnetized.

To confirm whether your watch is magnetized, you can take it to a watchmaker or jeweler who has a demagnetizer tool. The watchmaker can place your watch on the tool and determine whether it’s magnetized. Alternatively, you can use a compass to test your watch. Hold the compass close to your watch and see if the compass needle moves or is attracted to the watch. If it does, then your watch is likely magnetized.

You can also use the Lepsi app if you have an iphone. It is highly accurate

Can a phone magnetize a watch

Yes, a phone can magnetize a watch. Cell phones and other electronic devices such as speakers, computer monitors, and even some credit card readers have magnets inside them can emit electromagnetic fields that can magnetize a watch. When a watch is exposed to these magnetic fields, the steel parts inside the watch’s movement can become magnetized, causing the watch to run fast or even stop working altogether.

To avoid magnetizing your watch, it’s best to keep it away from electronic devices that emit strong magnetic fields. Store your watch in a different pocket or bag than your cell phone or other electronic devices. Additionally, you can take steps to demagnetize your watch periodically to ensure it’s running accurately.


By making demagnetizing a higher priority in your service procedures, you can easily eliminate one of the possible causes of lower amplitude and higher rates, allowing you to focus any needed troubleshooting on other issues without magnetism muddying the water.