SmCo magnets (Samarium Cobalt) are also part of the rare-earth magnet family. The Samarium Cobalt compound was discovered in 1966 by Dr. Karl J. Strnat. SmCo magnets were once the most powerful permanent magnets available, before being surpassed by NdFeB magnets.

Samarium Cobalt is produced from powdered metal, which is compacted in a magnetic field and subsequently sintered. During the sintering process, the compacted powder is subjected to heat treatment, allowing the material to achieve its full density and magnetic orientation.

SmCo magnets also provide a very strong magnetic field and offer excellent resistance to demagnetization. Unlike Neodymium magnets, they are also highly resistant to corrosion. SmCo magnets can operate at higher temperatures of up to 300°C and are widely used in applications where higher operating temperatures and greater resistance to corrosion and oxidation are crucial. The temperature coefficient of remanence is usually less than ±0.05%.

Two common compositions of SmCo magnets are SmCo₅ and Sm₂Co₁₇. They can be produced in sintered or bonded form. In general, SmCo magnets are more expensive than NdFeB magnets, while NdFeB magnets provide a higher magnetic strength.