Article by Todd Andersen of Pinball Renaissance

This is not the first Pinball News article concerning magnetized pinballs. The first, a very comprehensive and advanced report, can be found here. A second article mentions an alternate testing technique. This third article offers both a quick review and some very practical help.

This new article will again discuss how and why pinballs get magnetized. It will also show how to easily tell, without the use of special measuring equipment, if the pinballs in your game are magnetized. And lastly, it will cover two useful ways to demagnetize pinballs.


One of the characteristics of many metals is that they may become magnetized. No matter the method, this process is done at an atomic level; by orderly arranging the very molecules which make up the metal being magnetized.

Although many metals can get magnetized by several different methods, the metal pinballs in your pinball machine get magnetized by two methods. The first method is impact. The second is exposure to a magnetic field.

Impact: After one moderate blow with a hammer, the screwdriver shown below is lightly magnetized.

Striking a screwdriver with a hammer The screwdriver now picks up the paper clip

It is reasonable to assume that a heavy box of pinballs may have, at one time or another, been dropped. And accordingly, at least some of the balls in that box may have become magnetized.

Likewise, while two pinballs were being packaged and shipped, they may have been struck together and consequently may have been mutually magnetized. Having performed materials/packaging testing, I can tell you that impact testing in a major part of those associated testing requirements.

Exposure: On top of the impact-induced magnetism, after a half dozen pulses from a pinball coil, this same screwdriver is now even more magnetized. See both sets of pictures above and below.

The screwdriver is magnetized by a coil The screwdriver now holds the paperclip more solidly

There are perhaps a dozen electrical coils in the modern pinball machine. Some of those coils are electromagnets designed to manipulate the ball in play. Through exposure to the field produced by these magnets, a pinball may sometimes become magnetized.


After one ordered exposure to the alternating electrical field of the coil, the screwdriver is demagnetized.


Through observation during game play, I noticed, then verified, that the brand new pinballs I purchased were magnetized.

As the balls were new, I figured that any newer replacement pinballs might be magnetized as well, so I decided to demagnetize all of the original new balls. I also occurred to me that those with gilded or artfully decorated custom pinball might want to do the same - demagnetize versus replace.

From my experience, it is somewhat easy to intuitively be able to tell if more than one pinball is magnetized among a group of pinballs. However, if you only have one pinball in your game and strange things happen during gameplay, then that single ball might be magnetized.

What strange things you wonder? And, what hints can my intuition pick up on? There are several clues.

The easiest ways to know is if your pinballs are greatly magnetized are: when they constantly get stacked in the ball trough, continually have trouble kicking out into the shooter lane, or when they sit stationary in the ball trough.

The stacked ball, shown below, is one sign of a magnetized pinball.

A ball stuck in the trough kickout

If your trough is free of those pesky divots, and a freshly drained ball just hangs around, then that ball is probably magnetized.

A ball stuck in the trough

The hardest symptom to intrinsically determine correctly is the delayed drop. Even though the pinball in question may be somewhat - or even greatly - magnetized, this circumstance may still be hard to determine.

To do so, check for the following during game play. If a ball in play seems to momentarily freeze in place as it strikes another metal object or stays briefly captured after a game’s feature magnet gets turned off, then that ball may be magnetized.

As shown in the picture below, the lightly hit ball in play seems stuck to the captive ball - shown centre. Also, because the centre captive ball is magnetized, the associated careen shot is harder to complete as well.

Magnetized balls held together

When two pinballs stick together during game play, one or both of them are strongly magnetized. Although not the case in the following video link, this sticking may be observed during Mist Multiball in WMS's Bram Stoker’s Dracula pinball machine. You can test this scenario by placing suspect pinballs on a smooth, level surface and by getting one ball to cling to, or follow, another.

One ball sticks to another

A bottle cap or a paper clip may also be used to test if a metal object is weekly magnetized.  As you can see from the picture below, my custom Mini-Grip pocket knife momentarily was barely able to pick up a bottle cap. Therefore, the knife got magnetized. This happened after the knife was dropped to the floor just one time.

The knife picks up the bottle cap


Note: You might want to remove your watch or keep away from other delicate electronic devices (especially your pinball machine) as a precaution when degaussing.

We will show demagnetizing (degaussing) with the use of a monitor/television degaussing coil. If you don’t have access to this special coil, the motor coils in any large standard AC-powered vacuum cleaner will do the same job. But first, you must get the ball(s) out of your game. Consult your game’s manual or the pinball newsgroup for instructions on removing and replacing the pinballs in your machine.


Below are the instructions for using a degaussing coil to remove the residual magnetism from a colour picture tube.

Instructions for a degaussing coil


In general, use the following modified technique when employing either a degaussing tool or a vacuum cleaner’s motor to demagnetize your pinballs – one at a time.

  1. With the coil plugged into the appropriate AC source, centre the pinball you want to demagnetize about one foot (about a third of a meter) above the demagnetizer.
  2. Turn on the coil and move the pinball in small clockwise circles parallel to the demagnetizing source.
  3. Increase the size of the circles as you lower the pinball. Keeping your motion parallel to the degaussing tool.
  4. End by bringing the pinball very near the work surface and taking up almost the entire inner circumference of the coil. The inner part of the coil should almost touch the pinball for at least one entire revolution.
  5. Lastly, turn off the demagnetizing tool.

As most of us don’t readily have degaussing coils at our disposal, one solution is to bring your pinballs to a local television repair shop.


In the case of the vacuum cleaner, note that there is no need to remove the actual motor from the cleaner. The cleaner may be kept intact. Also, the larger the cleaner the better. One difference between using the dedicated coil and the vacuum cleaner motor is that the motor will not have an open center. So, in this case, you would demagnetize a pinball by circling it in front of the entire motor housing.


A great way to verify your success is by testing the pinball in question by trying to pick up a bottle cap or paper clip with it; just as you may have done to test it in the first place. This verification step may keep you from having to immediately remove the ball(s) from your game and encounter the frustration of properly demagnetizing it/them again.

One final note, don’t forget to check and/or demagnetize captive playfield balls too.

A captive ball from Pharaoh


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