Frequently Asked Questions

What are neodymium magnets?

Neodymium magnets are a rare earth magnet and represent the strongest permanent magnets currently available! They are composed of neodymium, iron and boron (NdFeB).

What are neodymium grades (N35, N40, N42, N45, N48, N50, N52)?

Neodymium Magnets are graded by their magnetic energy, the higher the grade, the higher the magnetic energy.

What does the magnets pull represent?

Pulling force is a measure of magnetic strength. This can quantifies how much weight (kg) the magnet can support when measured vertically from the magnet's pole when placed on an equal thickness of steel in comparison to the thickness of the magnet.

How are magnets magnetized (where are the north and south poles)?

The majority of magnets are magnetized across their thickness, for example a disc magnet such as a 20mm diameter x 2mm thick magnet would have the north pole on one circular face and the south on the other (opposite) face. In most cases the last measurement given is the length in which the magnet has been magnetized. This can be shown by a magnet such as an 50mm x 25mm x 10mm, the north is on one 50mm x 25mm face and the south is on the other, thus the magnet is magnetized across the 10mm thickness. It is also possible to have disc and cylinder magnets magnetized across the diameter so that the north is on one half of the curved face and the south on the opposite half, this is referred to as diametrically magnetized.

Why do some magnets say they are north or south?

Some magnets are designed to have a particular pole showing and the other covered (by adhesive for example), in this case the ‘showing’ face is then used to define the magnet. This arrangement is for use in particular applications, an example of this is adhesive magnets being used in the printing industry to hold folders closed, this application requires one magnet to have adhesive on the south and the other to have adhesive on the north so that the opposite (showing) face of the pair would be opposite poles and thus attract.

Do I need a North pole or a South pole when using a magnet on a steel surface?

If your application is using magnets on a steel surface, it does not matter which pole you use, neither is stronger or more efficient than the other. Magnetic poles only affect applications in which two magnets would be in close proximity and would then interfere with each other’s field depth.

Does temperature affect neodymium magnets?

Neodymium magnets are sensitive to heat, unless specified otherwise (i.e. High Temperature Magnets) the maximum operating temperature is 80°C. As a magnet is heated, for every degree C rise in temperature, the magnet will lose 0.11% of its magnetic strength. This loss is fully recovered on cooling unless the maximium operating temperature is exceeded causing any magnetism lost to be not recoverable upon cooling. For high temperature applications, samarium cobalt and high temperature neodymium magnets should be considered.

Why are neodymium magnets coated?

Neodymium magnets are coated in three layers, Nickel-Copper-Nickel to prevent oxidiation (rust) which would damage the magnets strength. Rusting can take place if the protective plating is damaged.

If I use two neodymium magnets together, does their strength double?

Using two magnets together would be the same as having one magnet of their combined size. For example, if you stacked two 10mm diameter x 2mm thick magnets on top of each other you would have effectively created a 10mm diameter x 4mm thick essentially doubling the magnets strength and pull. Once the length of the magnet exceeds the diameter of the magnet, the magnet is working at an optimum level and further additions to magnetic length will provide only small increases in performance.

Do magnets affect or damage electronic devices?

As a general rule, try to avoid close contact between magnets and electronic media. More common items to be damaged are CRT televisions, CRT computer monitors and magnetically stored media (such as hard drives & credit cards).

Should I be aware of any health or safety issues with neodymium magnets?

As a precaution, magnets should not be near pacemakers and similar medical devices. Magnets are sometimes used to relieve pain from conditions such as arthritis, back pain and carpal tunnel syndrome.