How can a magnet be demagnetized?

When the magnetic poles of a metallic object are aligned in the same direction, magnetism is produced. We say that demagnetization occurs when there is a change or some kind of disorder in the magnetic poles. That can happen for several reasons, now we tell you about them, just as we tell you about the existence of tools that allow us to magnetize or demagnetize in a matter of seconds.

Materials are demagnetized when the magnetic molecules inside a substance are randomly assigned, causing disorder inside the previously aligned magnetic material.

Among the many ways we can see to demagnetize a magnet we propose the following because they are the most common.

You can heat a magnet to the Curie point. The process can be done with two copper wires that you have connected to a generator or a battery. You can also help yourself with a torch. At the Curie point the temperature reached causes the ferromagnetic properties to be lost until it cools down again. The energy we have applied to the magnetic poles will make the magnet point in different directions, so the poles will be deformed.

It is also possible to demagnetize a magnet by hitting the ends of the magnet with a hammer, which will alter the order of the magnet. To hit a magnet with an object in general, applying force, is a good mechanism to achieve this objective.

In the same way you can also use an alternating current field to alter the order of the magnetic poles. You can do this by connecting the magnet to an alternating current circuit by inserting it into a solenoid: a loop of coiled copper wire surrounding a metal core and connected to an electric current.

There are also simpler methods, such as rubbing two magnets together, which can also, in some cases, demagnetize. 

Demagnetization may be voluntary or involuntary

Possibly, heating a piece of magnetized metal with a flame will generate demagnetization, destroying the order of the molecules inside the magnet. When a magnet is heated, each molecule is smeared with energy. This forces it to change and move, removing each molecule from the order it had inside the magnet and stripping the metal piece of its magnetization or leaving it with very little. This method is possibly one of the most used and the one that provides the best results.

In the same way, when a magnet is hammered or forged, the vibrations we are attempting by the impact on the magnet, generates the randomization of the magnetic molecules within it, breaking the order of the magnet. The more brute force we apply to it, the better results we will obtain.

We can also use alternating current, since it is capable of producing a magnetic field that can be moved and reduced to demagnetize materials. When we use the electric current and create this field, we carry the magnetic molecules of the magnet in different directions than they had previously. During the process, when the alternating current is altered or reduced, not all the molecules inside the magnet return to their previous positions, which causes the randomization of the molecules and the reduction of the force of the magnet.

Today there are many simple and inexpensive tools that work for magnetizing and also for demagnetizing. They are used to magnetize or demagnetize tools such as screwdriver tips.  It is a process that only takes a few seconds and very simple, so it allows the work to be done in just a few seconds.