Magnet materials: Pros and Cons

Neodymium magnets, Samarium Cobalt magnets, AlNiCo magnets and Ceramic magnets are all types of magnets.  They are composed of materials which, once given a magnetic charge, will retain their magnetism for years.

Not all permanent magnets are the same.  Many magnets can be used for many things.  How to select the right material for my application?

Each magnetic material has unique features resulting in specific advantages and disadvantages for a given application.  So, which one to choose from?

Let's talk about each their pros and cons

1) Neodymium magnets (NdFeB)

Neodymium is the strongest magnet available (roughly 10 times higher than ceramic magnets). It is also less expensive that Samarium Cobalt material due to its composition (an alloy made of neodymium (Nd), iron (Fe) and boron (B)).

Pros: Strongest material with medium cost

However, it doesn't have the high heat resistance or corrosion resistance of Samarium Cobalt, which could exclude it from use in certain applications.  Neodymium magnets are also very brittle and will crack under stress.

Cons: Maximum operating temperature (grade N42) is 80°C/176°F and very brittle.

Other features:

• strongest magnet alloy at up to 55MGOe
• Grades available from 33 to 55MGOe
• Operating temperature up to 230°C/446°F
• We have a large variety of neodymium magnets in stock

2) Samarium Cobalt (SmCo)

Samarium Cobalt alloy has high strength, a good corrosion resistance and high operating temperature needed in many applications.

Pros: High operating temperature, high strength for his weight

However, since it contains cobalt, it is more expansive than other materials.  You may want to consider using this alloy for applications where performance requirements outweigh cost. 

Cons : High cost

Other features:

• Often used in high temperature applications needing high magnetic performance and where stability over a wide range of temperatures is required
• Grades from 16 to 32 MGOe
• Operating temperature up to 350°C/662°F

3) AlNiCo

Aluminum-Nickel-Cobalt (AlNiCo) alloy uses less cobalt than Samarium Cobalt, making it more affordable.  The best option for high heat applications.

Pros: Low cost alloy with highest operating temperature

Since the AlNico alloy is not as strong as the other magnet materials, it will require a larger size magnet in order to obtain suitable performance.

Cons: Low strength

Other features:

• Ideal for corrosive and high heat applications up to 500°C/930°F
• Available in cast and sintered grades (Alnico 2, 5, 5-7, 8)
• Often used for sensors

4) Hard ferrite (ceramic)

Hard ferrite magnet, commonly called ceramic magnet, are the first generation of permanent magnets.  They provide low-cost solutions with high corrosion resistance.

Pros: Low cost, Corrosion resistant

Since these magnets are extremely brittle, machining requires diamond tooling and limits the final product to simple shapes.

Cons: Very brittle

Other features:

• Medium magnetic strength
• Relatively high operating temperatures up to 175°C/350°F
• Available in grade 5 & 8

How to select the right material for my application?

If you need a strong permanent magnet and you are not limited with the maximum operating temperature your best option would be our neodymium magnets.  We have a large selection of shapes in stock available for next business day delivery.

In the case you would need a magnet with a higher operating temperature such as the Samarium Cobalt or AlNiCo magnets please contact our magnet specialists and they will provide you with more informations.

As for hard ferrite or ceramic magnets, we carry a few of them in stock.  If you cannot find the hard ferrite magnet you are looking for, contact us and we will see how we could help you with your requirement.

Still not convinced?

You may find practical advise with other related articles :

• How to choose the right magnet?
• Neodymium magnets: How are they made?
• How does a permanent magnet work?
• What are neodymium magnets?