Do you want to store large magnets safely and we don't know how?

Accidents occur frequently, especially when removing and storing large magnets. In many cases, plastic separators are used to store magnets, but even so, the magnets tend to fly and cling to each other, usually carrying some skin with them.

To manage, pack and store large magnets, appropriate methods must be used and, in particular, certain safety aspects must be taken into consideration.

In fact, certain reception or storage departments in some factories are not familiar with the strength of permanent magnets and this can cause injury or broken parts. All personnel who may come into contact with this alloy should be aware of the dangers of handling these magnets. The brittle nature of the alloy can lead to flying chips if the magnets are allowed to impact each other or on a solid surface.

In this sense, storing large magnets can become a great danger if the required precaution is not taken.

What are the methods for safely storing large magnets?

The main method for storing large magnets is with the use of wooden boxes. Many times, these products must be shipped, or simply packaged for safekeeping but must have this protection because it is considered a dangerous product (because of its size), due to the field density emanating from the sides of the package exceeds a specified value.

Therefore, for storing large magnets, as well as for their use and cleaning, they must be protected mainly from three types of factors, which favour demonetization and even destruction. These aspects are:

• Mechanical protection. They should not be hit, therefore, it is convenient to leave them "closing magnetic circuits", joined to iron pieces, inside a box with padded interior surfaces. Even if the blows are not strong enough to break them, they are very effective in reducing the magnetization of the magnet. This is most pronounced when the magnets are at a higher temperature (such as in industries where some magnets are washed with steam jets).

• Chemical protection. The magnets must not come into contact with a corrosive or humid atmosphere. Therefore, it is convenient to place them in hermetically sealed boxes, with particles of a desiccant (such as silica gel). Rare earth permanent magnets such as samarium and neodymium magnets (such as SmCo5, Sm2Co17 or Nd2Fe14B) oxidize easily only when in contact with oxygen in the air. Therefore, in general, its surface is metallized with nickel.

• Thermal protection. Magnets should be stored and used at the lowest possible temperature, as this accelerates their demagnetisation. Therefore, for a given application, a magnet should be chosen whose material has a critical temperature Tc of approximately 3 times the operating temperature. For example, magnets that are magnetically the best are the worst from a temperature point of view. In fact, Nd2Fe14B has Tc = 310 degrees Celsius and therefore it is not recommended to put it at temperatures well above 100 degrees Celsius.

If you want to know more about safely storing large magnets, IMA can advise you on the best magnetism solution for your project. If you have questions, you can contact us.

On the other hand, special care must be taken with metal shelves with little separation, because they can cause magnets to jump or move when accessed. Therefore, a recommended safety distance between devices and magnets should be maintained, and large magnets should not be stored near equipment with cathode ray tubes (CRTs) or magnetic storage media. Magnets that are not of the same alloy may need to be buffered from each other due to demagnetizing effects.

In short, to combat accumulated waste, magnets should be kept in closed, clean containers. The magnets must remain in the attraction condition with all spacers intact.

Why is that? I don't know. Because this will attract ferrous particles from the air and surrounding surfaces. These particles will accumulate and appear as small "hairs" on the surface of the magnet or packaging.

In this line, in addition to using protectors or wooden boxes, large magnets should be stored in an environment of low humidity and mild temperature.