SmCo5 magnet is composed of SmCo alloy with Sm Co ratio of 1:5. According to weight, Sm accounts for 36% of the total. This SmCo alloy usually contains 36% Sm and a small amount of Co. This series of SmCo magnets can provide a maximum magnetic energy product of 25 MGOe and a reversible temperature coefficient of - 0.05% / ℃. In addition, this series is easier to calibrate to a specific magnetic field than Sm2Co17 series. The Sm2Co17 magnet consists of SmCo alloy with a SmCo ratio of 2:17. It also contains other elements, such as iron, copper, zirconium and hafnium in a small amount. The magnetic energy product of this property is higher, up to 32 MGOe, and the reversible temperature coefficient is - 0.03% / ℃.

The specific proportion is Sm: 23-28%; Rare earth metal Cobalt: 48-52%; Metallic element Fe: 14-17%; Metal element Cu: 5-7%; A small amount of Zr: 2-3% was added.