China permanent magnet manufacturer:

NdFeB magnets VS SmCo magnet

Rare earth permanent magnets are classified into samarium cobalt magnets and neodymium iron boron magnets according to their materials. So what is the difference between samarium cobalt magnet and neodymium iron boron magnet?

Main raw materials

SmCo magnet

Samarium cobalt magnet is a kind of magnetic material made of samarium, cobalt and other metal rare earth materials through mixing ratio, melting into alloy, crushing, pressing, and sintering.

NdFeB magnet

The main raw materials of neodymium iron boron magnets are metal neodymium, pure iron, and boron. The three main raw materials are sintered and pressed.

Comparison of Samarium Cobalt Magnet (2:17) and NdFeB Magnet

Different ingredients

Neodymium iron boron magnet:

  • Rare earth metal neodymium 29%-32.5%
  • Metal element iron 63.95-68.65%
  • Non-metal element boron 1.1-1.2%
  • Add a small amount of dysprosium 0.6-1.2% niobium 0.3-0.5% aluminum 0.3-0.5% copper 0.05-0.15% and other elements.

Samarium Cobalt Magnet 2:17:

  • Samarium rare earth metal Sm: 23-28%
  • Rare earth metal cobalt Co: 48-52%
  • Metal element iron Fe: 14-17%
  • Metal element copper Cu: 5-7%
  • Add a small amount of zirconium Zr: 2-3

Processing characteristics

Both materials are very brittle, relatively speaking, NdFeB is easier to machine.

Maximum magnetic energy product

The maximum energy product of a samarium cobalt magnet is 32M, while the maximum energy product of NdFeB is 52M.
NdFeB magnets are the strongest in the industry. NdFeB magnets are called “magnet kings”, which means that the magnetic force of NdFeB magnets is much higher than that of samarium cobalt magnets.

Temperature resistance characteristics

The temperature resistance of neodymium iron boron magnets is not very ideal, and it is only suitable for working in a working environment of 230 ℃.
The temperature resistance of samarium cobalt magnets is better than that of neodymium iron boron magnets, and it can work at a high temperature of 230°C to 350°C. NdFeB material with a maximum temperature of 220 degrees can reach 220 degrees with a material above 28AH, and samarium cobalt high temperature magnets can reach a maximum of 350 degrees but require Sm2Co17 materials.
The temperature coefficient of the remanence of NdFeB is relatively large. The higher the temperature rise, the lower the remanence. The temperature coefficient of the remanence of SmCo is very low. At the same temperature, the demagnetization of SmCo is much less than that of NdFeB. In addition, NdFeB must be electroplated, otherwise it is easily oxidized and corroded and weathered. Samarium cobalt generally does not need to be electroplated, but if it is used in a harsh environment, it will last longer after electroplating and be more beautiful.


Neodymium iron boron rare earth elements neodymium and boron account for a small proportion, so the price is relatively cheap; samarium cobalt magnets have more rare earth elements samarium and cobalt, about 70% are samarium and cobalt, so the price is relatively expensive.


Samarium cobalt magnets usually do not require surface treatment, and NdFeB magnets are easily oxidized and require surface electroplating treatment.

Source: China NdFeB Magnet Manufacturer –



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