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What are the differences between the different magnet formulations you sell?
Posted on Oct. 9, 2012
NdFeB (Neodymium-Iron-Boron) -- The most powerful 'rare-earth' permanent magnet composition known to mankind, and our specialty. This formulation is relatively modern, and first became commercially available in 1984. NdFeB magnets have the highest B, Br, and BHmax of any magnet formula, and also have very high Hc (see below for definitions). They are however very brittle, hard to machine, and sensitive to corrosion and high temperatures. Useful in the home, workshop, pickup truck, laboratory, wind turbine, starship and more. We carry both new and surplus stock in many sizes and shapes.In almost all magnet applications, NdFeB are the best choice for incredible strength and coercivity at a reasonable price! In power generation applications, NdFeB magnets can be expected to give 4-5 times the power output of ceramic magnets.
Ferrite (Ceramic) -- Also known as 'hard ceramic' magnets, this material is made from Strontium or Barium Ferrite. It was developed in the 1960s as a low-cost and more powerful alternative to AlNiCo and steel magnets. Less expensive than NdFeB magnets, but still very powerful and resistant to demagnetization. Useful everywhere. We carry both new and surplus in multiple shapes and sizes. Ferrite magnets are lower in power (B, Br, BHmax) compared to other formulations, and are very brittle. However, they have very high Hc and good Tc (see below), and are quite corrosion-resistant. A very cost-effective choice.
AlNiCo (Aluminum-Nickel-Cobalt) for medium strength and excellent machinability. Developed in the 1940s and still in use today. They perform much better than plain steel, but are much weaker in strength (lower B, Br and BHmax) and must be carefully stored since they are prone to demagnetization. Contact with a NdFeB magnet can easily reverse or destroy the field of an AlNiCo magnet.
SmCo (Samarium Cobalt)-- for high power and resistance to high temperatures and corrosion. Developed in the 1970s, these were the first so-called 'rare earth' magnets. They are almost as powerful as NdFeB magnets, and far more powerful than all the others (high B and Br). They are the most expensive magnet formulation, and usually only used where resistance to high temperatures (high Tc) and corrosion are needed. Also very brittle and hard to machine.
Bonded (flexible)-- magnets are a rubberized formulation often seen on refrigerators and magnetic signs. Though they may be manufactured from any magnet formulation when powerdered and mixed with rubberizer, the result is always less powerful than a traditional sintered magnet of any formula. Used only where unusal and difficult shapes are needed.
Ferrite (Ceramic) -- Also known as 'hard ceramic' magnets, this material is made from Strontium or Barium Ferrite. It was developed in the 1960s as a low-cost and more powerful alternative to AlNiCo and steel magnets. Less expensive than NdFeB magnets, but still very powerful and resistant to demagnetization. Useful everywhere. We carry both new and surplus in multiple shapes and sizes. Ferrite magnets are lower in power (B, Br, BHmax) compared to other formulations, and are very brittle. However, they have very high Hc and good Tc (see below), and are quite corrosion-resistant. A very cost-effective choice.
AlNiCo (Aluminum-Nickel-Cobalt) for medium strength and excellent machinability. Developed in the 1940s and still in use today. They perform much better than plain steel, but are much weaker in strength (lower B, Br and BHmax) and must be carefully stored since they are prone to demagnetization. Contact with a NdFeB magnet can easily reverse or destroy the field of an AlNiCo magnet.
SmCo (Samarium Cobalt)-- for high power and resistance to high temperatures and corrosion. Developed in the 1970s, these were the first so-called 'rare earth' magnets. They are almost as powerful as NdFeB magnets, and far more powerful than all the others (high B and Br). They are the most expensive magnet formulation, and usually only used where resistance to high temperatures (high Tc) and corrosion are needed. Also very brittle and hard to machine.
Bonded (flexible)-- magnets are a rubberized formulation often seen on refrigerators and magnetic signs. Though they may be manufactured from any magnet formulation when powerdered and mixed with rubberizer, the result is always less powerful than a traditional sintered magnet of any formula. Used only where unusal and difficult shapes are needed.