Rare earth magnets are magnets made from alloys of rare earth elements, including neodymium iron boron or samarium cobalt. They are currently the strongest type of permanent magnets, producing significantly stronger magnetic fields than other types of magnets like ceramic or alnico magnets. This quality has led to them replacing alnico and ferrite magnets in many applications, including head actuators for computer hard disks, magnetic resonance imaging (MRI) systems, loudspeakers and headphones, motors, and more.
At Adams Magnetic Products, we’ve engineered and manufactured magnetic products for over 70 years. This extensive experience provides us with the knowledge and skills needed to deliver magnet solutions for nearly any customer application. Below, we highlight the rare earth magnet products we offer and outline some of their typical applications.
Types of Rare Earth Magnets From Adams Magnetic Products
Among commercial magnet materials, the rare earth magnets made from neodymium iron boron are the most powerful in the marketplace. Available in both sintered and bonded forms, this class of rare earth material possesses the highest Br, high BHmax (approximately 10–53 MGOe), and relatively high Hc. Other key characteristics include:
- Highest power-to-weight ratio
- High resistance to demagnetization
- Low machinability (no conventional drilling, turning, milling)
- Suitability for magnetization in any direction (given the proper alignment) and multiple pole magnetization ( provided the proper magnetizing fixture is available)
In many cases, neodymium magnets are a less brittle and more economical alternative to samarium cobalt magnets. However, they are only suitable for certain applications because of their sensitivity to high temperatures and susceptibility to oxidation.
We offer the following types of neodymium magnets:
Rare Earth Magnets Stock Selection
Adams offers a wide selection of Rare Earth magnet products. Click on your desired product type for stock product specifications.
Neodymium Disc Magnets
View a small sampling of our stock Neodymium disc magnets in several grades.
Neodymium Block Magnets
Adams offers Neodymium magnets in square and rectangular blocks.
Neodymium Ring Magnets
We stock NdFe ring magnets, magnetized through the thickness.
Samarium Cobalt Disc Magnets
View our stock SmCo disc magnets, in grades 18-26.
Samarium Cobalt Blocks
Our SmCo block magnets offer good thermal stability!
View our stock Neodymium magnets with adhesive, great for closures.
Samarium Cobalt Magnets
Like neodymium iron boron, samarium cobalt is a rare earth material available in both sintered and bonded forms. The two materials share many attributes, including High Br, high Hc, relatively high BHmax (approximately 18–33 MGOe), high resistance to demagnetization, low machinability, and suitability for multiple pole magnetization given the proper magnetizing fixture is available. However, compared to neodymium iron boron, samarium cobalt offers greater corrosion resistance and thermal stability, making it better suited for applications involving corrosive chemicals or extreme temperatures.
We offer the following types of samarium cobalt magnets:
Demagnetization Curves for Our Rare Earth Magnet Products
Many factors influence how a rare earth magnet will perform within a magnetic circuit, such as its permeance coefficient and operating environment. Permanent magnets that are fully magnetized have magnetic domains that are aligned in a specific way. Certain conditions can cause some domains to fall out of alignment, triggering the magnet to lose some or all of its magnetic field. The two primary ways a permanent magnet can be demagnetized are by:
- Heating. All magnetic materials have a temperature limit known as the Curie Temperature. At this point, the thermal agitations within the material apply more force than the resistance to movement provided by the magnetic domains. When the bulk of the material reaches this temperature, it shows virtually no net magnetization.
- Applying a demagnetizing field. A magnet can be partially demagnetized by applying a reverse magnetic field on it. This effect can be studied by looking at its demagnetization curve, which provides information about the magnetic characteristics, including how strong its magnetic field is and how resistant it is to demagnetization.
Click to view the demagnetization curves for our rare earth magnet products.
Applications of Rare Earth Magnets
At Adams Magnetic Products, we offer a broad selection of rare earth magnets, including nickel-plated neodymium disc, block, ring magnets, samarium cobalt block, ring, and disc magnets. These products are available in various diameters, thicknesses, and grades to suit different magnet applications.
One of the markets that regularly rely on our magnet products is the military and defense industry. We have the knowledge, understanding, and systems in place to fully comply with the Arms Export Control Act (AECA) and International Traffic in Arms Regulations (ITAR), making us the ideal supplier for magnets and magnetic products for the defense and military industries. As an ITAR registered supplier, customers can rest assured their data, and confidential information is safe with us. We are also their source for Defense Federal Acquisition Regulations Supplement (DFARS) compliant material, helping them obtain the right materials for their DoD needs.
Besides military and defense applications, our magnets are also used for the following:
- Cordless tools
- Displays and signs
- Electrical power steering systems
- Loudspeakers and headphones
- Magnetic bearings and couplings
- Magnetic guitar pickups
- Magnetic resonance imaging (MRI) systems
- Microwave devices
- Motors and generators
- Package closures
- Spectroscopy dipoles
If the application requires the magnet to be glued in or on the assembly, several factors must be considered to ensure the effective performance of the magnet, the adhesive, and the resulting bond. These include the chemical and physical properties of the magnets and the surfaces to which they are affixed. Detailed coverage of all these factors, along with some adhesives to try, is covered in our white paper, Gluing Magnets.
Rare Earth Magnets From Adams Magnetic Products
Our technical experts are ready to answer your questions and address your magnetic needs. Whether it’s selecting a magnet to fit an application, choosing the most cost-effective material, or reviewing options from what is available in the market, we are here to help with:
- Application and Design Engineering Assistance
- Testing/Analysis of Magnetic Materials
- Magnetic Circuit Analysis/FEA
- Value Analysis/Value Engineering Support
- Inventory Management Programs
By partnering with us for your magnet needs, you benefit from our:
- Commitment to value. We define value as having the right products available at the right time and delivering them as promised, defect-free, at competitive prices. We are committed to delivering outstanding value to customers at every opportunity.
- Commitment to quality. We maintain ISO 9001:2015 certification, reinforcing our strong operational processes and commitment to continuous improvement. We have a standard of zero defects in everything we do.
For more information on rare earth magnets, check out our rare earth resource library or use our magnetic field calculator. To get started on choosing a magnet product for your application, request a quote.