Samarium cobalt magnets are the second-generation rare earth permanent magnet materials, divided into two series: SmCo5 (1:5 type) and Sm2Co17 (2:17 type).
They feature high energy product (14-32 MGOe), excellent temperature stability (Curie temperature 750-800°C, maximum operating temperature 250-350°C), and corrosion resistance without surface coating. With low mechanical strength and high brittleness, they require specialized processing. Despite high cost due to scarce raw materials, their performance exceeds neodymium iron boron in high-temperature and harsh environments, widely used in aerospace, high-temperature motors, sensors, and microwave devices.
The 2024 XB/T 507-2024 standard further regulates low temperature coefficient and ultra-high temperature (500°C) grades, promoting applications in precision instruments and extreme environments.
SmCo Mangnet Grade
| Composite | Type | Grade | Residual Induction/BR (Gauss) | Coercive Force/Hc (Oe) | Intrinsic Coercive Force/Hci (Koe) | Max.Energy Product/Bhmax (MGOe) | Maximum Operating Temp (°C/°F) | Curie Temp (°C/°F) |
| Sm1Co5 | N | 16 | 8100 | 7800 | 15 | 16 | 127/260 | 482/899 |
| Sm1Co5 | N | 18 | 8500 | 8300 | 15 | 18 | 143/289 | 482/899 |
| Sm1Co5 | N | 20 | 9000 | 8500 | 15 | 20 | 167/332 | 482/899 |
| Sm1Co5 | N | 22 | 9200 | 8900 | 15 | 22 | 175/347 | 482/899 |
| Sm1Co5 | N | 24 | 9600 | 9200 | 15 | 24 | 190/374 | 482/899 |
| Sm1Co5 | NS | 16S | 7900 | 7700 | 23 | 17 | 135/275 | 482/899 |
| Sm1Co5 | NS | 18S | 8400 | 8100 | 23 | 19 | 151/303 | 482/899 |
| Sm1Co5 | NS | 20S | 8900 | 8600 | 23 | 21 | 167/332 | 482/899 |
| Sm1Co5 | NS | 22S | 9200 | 8900 | 23 | 23 | 183/361 | 482/899 |
| Sm1Co5 | NS | 24S | 9600 | 9300 | 23 | 25 | 199/390 | 482/899 |
| Sm1Co5 | NX | 10X | 6200 | 6100 | 23 | 11 | 88/190 | 572/1061 |
| Sm2Co17 | NL | 24L | 9500 | 6800 | 8-12 | 24 | 191/375 | 482/899 |
| Sm2Co17 | NL | 26L | 10200 | 6800 | 8-12 | 26 | 207/404 | 482/899 |
| Sm2Co17 | NL | 28L | 10500 | 6800 | 8-12 | 28 | 220/428 | 482/899 |
| Sm2Co17 | NL | 30L | 10800 | 6800 | 8-12 | 30 | 240/464 | 482/899 |
| Sm2Co17 | NL | 32L | 11000 | 6800 | 8-12 | 32 | 255/491 | 482/899 |
| Sm2Co17 | NM | 26M | 10200 | 8500 | 12-18 | 26 | 207/404 | 572/1061 |
| Sm2Co17 | NM | 28M | 10500 | 8500 | 12-18 | 28 | 220/428 | 572/1061 |
| Sm2Co17 | NM | 30M | 10800 | 8500 | 12-18 | 30 | 240/464 | 572/1061 |
| Sm2Co17 | NM | 32M | 11000 | 8500 | 12-18 | 32 | 255/491 | 572/1061 |
| Sm2Co17 | N | 24 | 9500 | 8700 | 18 | 24 | 191/375 | 572/1061 |
| Sm2Co17 | N | 26 | 10200 | 9400 | 18 | 26 | 207/404 | 572/1061 |
| Sm2Co17 | N | 28 | 10500 | 9700 | 18 | 28 | 220/428 | 572/1061 |
| Sm2Co17 | N | 30 | 10800 | 9900 | 18 | 30 | 240/464 | 572/1061 |
| Sm2Co17 | N | 32 | 11000 | 10200 | 18 | 32 | 255/491 | 572/1061 |
| Sm2Co17 | NH | 24H | 9500 | 8700 | 25 | 24 | 191/375 | 662/1223 |
| Sm2Co17 | NH | 26H | 10200 | 9400 | 25 | 26 | 207/404 | 662/1223 |
| Sm2Co17 | NH | 28H | 10500 | 9700 | 25 | 28 | 220/428 | 662/1223 |
| Sm2Co17 | NH | 30H | 10800 | 9900 | 25 | 30 | 240/464 | 662/1223 |
| Sm2Co17 | NH | 32H | 11000 | 10200 | 25 | 32 | 255/491 | 662/1223 |
| Sm2Co17 | NX | 22X | 9400 | 8400 | 15-20 | 22 | 175/347 | 572/1061 |
