Resources Products

Do Magnets Lose Their Magnetism over Time?

Yes, magnets will weaken over time. They lose some of their magnetic field strength over time, but the surrounding environment is the main cause of this.

Ⅰ. How does a magnet lose its magnetism?

How to demagnetize a magnet? We have already mentioned various factors that can lead to demagnetization. The two biggest common factors are heat and effects from other magnetic fields.

1. Hot

If a wholesale magnet assembly is heated above the Curie point of a ferromagnetic material, it will lose its magnetism. Depending on how much you heat and break the magnet, it can recover.

If it doesn't heat above the Curie point, the magnet will recover when it comes back to room temperature, or you can re-magnetize it with another magnet.

2. Improper storage

The smco bar magnet for science classes has clear north and south pole markings if it is stored or stacked with the north pole. This causes them to lose their magnetism faster than normal, instead you want to store them as the north pole of one touches the south pole of the other. The magnets will attract each other in this direction and maintain each other's magnetic fields.

You can also store horseshoe magnets this way. Or you can put a small piece of iron called a "retainer" on the pole to keep it strong.

3. Age

When you look at a magnet on a table, it appears to be perfectly still, but in reality its atoms vibrate in random directions. Energy from normal temperature produces these vibrations.

After a few years, the vibrations caused by the temperature change finally randomize the magnetic orientation of its magnetic domains. Some magnetic materials remain magnetic longer than others. Scientists use properties such as coercivity and retention to measure how well a magnetic material retains its strength.

4. Influence

A very violent impact pushes the magnet's atoms, causing them to rearrange against each other. In the presence of a strong magnetic field consistent with the magnet, the atoms will rearrange in the same direction, increasing the strength of the magnet.

Without a strong magnetic field to guide the atoms, they would rearrange in random directions, weakening the magnet. Most permanent magnets can withstand multiple drops, but lose their strength with repeated hits with a hammer.

Ⅱ. The maintenance of magnets

With proper care and maintenance, magnets can last indefinitely. For information on how to care for your magnets, here are some tips:

1. Storage of magnets

Storing magnets with a retainer: A retainer is a small piece of iron that is usually temporarily added between the north and south poles of the magnet. It prevents the magnet from demagnetizing by changing the direction of the magnetic field.

Storing magnets in pairs: Store magnets in pairs to avoid contact between the north and south sides. Two poles of the same arrangement must never touch, as this will cause the magnetic field to repel and cause the magnet to weaken over time.

Dry places: Magnets stored in humid environments are prone to corrosion. Corrosion can affect the strength of the magnets, especially if they are rusted, which can cause air gaps. This would create an unsafe bond to the ferromagnetic material. Also, if the magnet gets wet, it can cause the laminate to blister. If you must use the magnet in a wet environment, be sure to use a magnet designed for water, and to dry and clean the magnet regularly.

Store in non-ferromagnetic spaces: When storing multiple magnets, store them in non-ferromagnetic containers. A good example is a tightened wooden crate or container. A container for storing the magnet will help the magnet avoid attracting any unwanted metal fragments.

2. Avoid magnet demagnetization

A number of factors can cause a magnet to weaken. Follow these simple tips to keep your magnets strong and useful:

Keep your customised magnetic assemblies away from heat. At the atomic level, placing a magnet in a high temperature area will bring the chemical and physical properties of the magnet to a level where it will no longer be the same. This will cause them to lose power.

Try to keep your magnets away from strong currents. Strong currents can interfere with the magnetic field, causing the magnet to demagnetize.

3. Protective magnet coating

In order to avoid corrosion damage, it is necessary to protect the surface of the permanent magnet material during use, such as electroplating with gold, nickel, zinc, and tin, and spraying epoxy resin on the surface.

Related Article


Please fill the form to let us know your need. Our sales will get in touch with you ASAP.

Related Products