What are neodymium magnets?
Neodymium magnets are powerful permanent magnets made from an alloy of neodymium, iron and boron (NdFeB). They were developed independently in the United States and Japan in the early 1980s.
Neodymium magnets are widely used in electric motors, wind turbine generators and electronic devices. They are also popular for hobby projects such as magnetic knife holders and DIY fridge magnets.
A neodymium magnet may look like an ordinary piece of solid metal, but it is brittle. Sintered neodymium magnets are made by pressing powdered material into shape and heating it to bond the particles together. They are usually given a protective coating, such as nickel. Despite their metallic appearance, they can chip or crack if dropped or allowed to collide.
What kinds of magnets are there?
Magnets can be classified in several ways. When choosing permanent magnets, you will commonly encounter these four material types:
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Neodymium magnets (NdFeB)
Neodymium magnets provide high magnetic strength in a compact size. They are sometimes called super magnets or power magnets. Many have a shiny, silver-coloured nickel coating, but other coatings include copper, gold, PTFE (Teflon) and rubber. -
Ferrite magnets
Ferrite magnets are generally less powerful than neodymium magnets of a similar size, but they are inexpensive and resistant to corrosion. They can often withstand higher operating temperatures than standard neodymium magnets. They are typically grey-black in colour. -
Samarium cobalt magnets (SmCo)
SmCo magnets combine high magnetic strength with good temperature stability and corrosion resistance. They are useful where heat or environmental conditions make neodymium magnets unsuitable. However, they are brittle, and their suitability depends on the grade and application. -
Alnico magnets (AlNiCo)
Alnico magnets contain aluminium, nickel and cobalt. They offer good temperature stability and can operate at high temperatures, depending on the grade. However, they are more susceptible to demagnetisation than neodymium magnets and should not be considered impact-resistant.
What should I know before buying magnets?
Even a small neodymium magnet can exert a surprisingly strong force. Before choosing one, consider how it will be mounted, the direction of the load, the operating temperature and any exposure to moisture.
- Handle magnets carefully. Neodymium magnets can chip or shatter if dropped or allowed to collide. If you need a magnet with a protective steel housing, consider pot magnets.
- Check the operating temperature. Temperature limits vary between products. Exceeding the specified maximum operating temperature can cause permanent loss of magnetic strength. Contact us about custom magnets if you need a magnet for higher temperatures.
- Choose suitable protection against moisture. Neodymium magnets can corrode if moisture reaches the magnetic material. A coating or enclosure can improve protection, but rubber or PTFE alone does not establish that a product is waterproof. Check the product's suitability for your environment. Alternatively, consider ferrite magnets if lower magnetic strength is acceptable.
- Keep strong magnets away from children. These magnets are not toys. Broken magnets can have sharp edges, and swallowed magnets can cause serious internal injuries.
- Understand the stated holding force. The holding force shown in kilograms describes the force needed to pull a magnet away from a test surface under specified conditions. Actual performance depends on the magnet's size, shape and magnetic grade, as well as the surface material, thickness, condition and direction of the load. A magnet generally carries less weight on a vertical surface than its direct pull rating suggests. The stated holding force is not a safe working load.
- Compare more than size when assessing price. Price depends on factors such as dimensions, magnetic grade, coating, manufacturing requirements and order quantity. Very small magnets can cost more than their size suggests because they still need to be manufactured, inspected, counted and packaged.
- Check availability and delivery times. Standard products are not necessarily in stock at all times. Check the product page or contact us to confirm availability and expected delivery.
- Ask about custom options. If you cannot find the magnet you need, it may be possible to manufacture it. Read more about custom magnets.
Need help?
If you are unsure which neodymium magnets to choose, contact us at info@brisingi.com. We can help you choose a magnet for your application. You can also visit our FAQ for answers to common questions about neodymium magnets.