Samarium Cobalt (SmCo) Magnets
SmCo₅ & Sm₂Co₁₇ · 300°C High-Temperature Grades
The go-to magnet when NdFeB can't handle the heat. Operating temperatures up to 300°C with minimal flux loss. No coating required — inherently corrosion resistant. Trusted by aerospace, defense, and medical device manufacturers worldwide.
What Are SmCo Magnets?
Samarium Cobalt (SmCo) is a rare earth permanent magnet material with the best temperature stability and corrosion resistance of any commercial magnet. Two families exist: SmCo₅ (1:5 type, developed 1970s) and Sm₂Co₁₇ (2:17 type, higher energy product). Both offer exceptional performance in harsh environments where NdFeB fails.
Simplicity & Reliability
Single-phase SmCo₅ with moderate energy product (16-22 MGOe) but the highest coercivity. Easier to magnetize and more predictable in extreme environments. Preferred for precision instruments.
Higher Energy Output
Multi-phase Sm₂Co₁₇ with precipitation-hardened cellular structure. Higher energy product (22-30 MGOe) than 1:5 type. Dominant choice for motors, generators, and high-power applications.
Set It and Forget It
Reversible temperature coefficient of remanence: -0.03%/°C (vs -0.12%/°C for NdFeB). That means SmCo loses only 3% of its flux going from 20°C to 120°C — NdFeB loses ~12%. Critical for precision sensors and instruments.
SmCo Property Comparison
SmCo₅ vs Sm₂Co₁₇ properties. Measured at 20°C per IEC and MMPA standards.
| Property | SmCo₅ (18) | SmCo₅ (22) | Sm₂Co₁₇ (26) | Sm₂Co₁₇ (30) | Unit |
|---|---|---|---|---|---|
| Remanence (Br) | 8.5-9.0 | 9.0-10.0 | 10.5-11.0 | 11.0-11.5 | kGs |
| Coercivity (Hcb) | 7.5-8.5 | 8.0-9.0 | 9.5-10.0 | 10.0-10.5 | kOe |
| Intrinsic Coercivity (Hci) | ≥15 | ≥15 | ≥18 | ≥20 | kOe |
| Max Energy Product (BH)max | 17-20 | 20-23 | 25-28 | 28-30 | MGOe |
| Max Operating Temp | 250 | 250 | 300 | 300 | °C |
| Density | 8.2 | 8.2 | 8.4 | 8.4 | g/cm³ |
| Curie Temperature | 700 | 720 | 820 | 820 | °C |
| Temp Coeff. (Br) | -0.045 | -0.045 | -0.030 | -0.030 | %/°C |
SmCo Magnets Grades And Properties
Comprehensive grade list with typical magnetic properties. Click PDF to download the demagnetization curve and full specification sheet for each grade.
| Name | Download | Grade | Br mT (kGs) |
Hcb kA/m (kOe) |
Hcj kA/m (kOe) |
(BH)max kJ/m³ (MGOe) |
αBr %/°C |
βHcj %/°C |
|---|---|---|---|---|---|---|---|---|
| Sm2Co17 63/199 | S10H | 580-710 (5.8-7.1) | ≥422 (≥5.3) | ≥1990 (≥25) | 63-95 (8-12) | 0.03 | 0.2 | |
| Sm2Co17 79/199 | S12H | 650-760 (6.5-7.6) | ≥478 (≥6.0) | ≥1990 (≥25) | 79-111 (10-14) | 0.03 | 0.2 | |
| Sm2Co17 95/199 | S14H | 710-830 (7.1-8.3) | ≥525 (≥6.6) | ≥1990 (≥25) | 95-127 (12-16) | 0.03 | 0.2 | |
| Sm2Co17 119/199 | S16H | 790-860 (7.9-8.6) | ≥589 (≥7.4) | ≥1990 (≥25) | 119-143 (15-18) | 0.03 | 0.2 | |
| Sm2Co17 135/199 | S18H | 830-890 (8.3-8.9) | ≥605 (≥7.6) | ≥1990 (≥25) | 135-159 (17-20) | 0.03 | 0.2 | |
| Sm2Co17 151/199 | S20H | 870-930 (8.7-9.3) | ≥653 (≥8.2) | ≥1990 (≥25) | 151-175 (19-22) | 0.03 | 0.2 | |
| Sm2Co17 159/199 | S22H | 910-980 (9.1-9.8) | ≥693 (≥8.7) | ≥1990 (≥25) | 159-183 (20-23) | 0.03 | 0.2 | |
| Sm2Co17 175/199 | S24H | 960-1030 (9.6-10.3) | ≥724 (≥9.1) | ≥1990 (≥25) | 175-199 (22-25) | 0.03 | 0.2 | |
| Sm2Co17 191/199 | S26H | 1010-1060 (10.1-10.6) | ≥733 (≥9.2) | ≥1990 (≥25) | 191-215 (24-27) | 0.03 | 0.2 | |
| Sm2Co17 207/199 | S28H | 1040-1090 (10.4-10.9) | ≥749 (≥9.4) | ≥1990 (≥25) | 207-231 (26-29) | 0.03 | 0.2 | |
| Sm2Co17 222/199 | S30H | 1080-1110 (10.8-11.1) | ≥773 (≥9.7) | ≥1990 (≥25) | 222-247 (28-31) | 0.035 | 0.2 | |
| Sm2Co17 239/199 | S32H | 1120-1160 (11.2-11.6) | ≥812 (≥10.2) | ≥1990 (≥25) | 239-263 (30-33) | 0.038 | 0.2 | |
| Sm2Co17 247/199 | S34H | 1150-1180 (11.5-11.8) | ≥835 (≥10.5) | ≥1990 (≥25) | 247-270 (31-34) | 0.04 | 0.25 | |
| Sm2Co17 255/199 | S35H | 1170-1200 (11.7-12.0) | ≥860 (≥10.8) | ≥1990 (≥25) | 255-278 (32-35) | 0.04 | 0.25 | |
| Sm2Co17 63/159 | S10 | 580-710 (5.8-7.1) | ≥422 (≥5.3) | ≥1592 (≥20) | 63-95 (8-12) | 0.03 | 0.2 | |
| Sm2Co17 79/159 | S12 | 650-760 (6.5-7.6) | ≥478 (≥6.0) | ≥1592 (≥20) | 79-111 (10-14) | 0.03 | 0.2 | |
| Sm2Co17 95/159 | S14 | 710-830 (7.1-8.3) | ≥525 (≥6.6) | ≥1592 (≥20) | 95-127 (12-16) | 0.03 | 0.2 | |
| Sm2Co17 119/159 | S16 | 790-860 (7.9-8.6) | ≥589 (≥7.4) | ≥1592 (≥20) | 119-143 (15-18) | 0.03 | 0.2 | |
| Sm2Co17 135/159 | S18 | 830-890 (8.3-8.9) | ≥605 (≥7.6) | ≥1592 (≥20) | 135-159 (17-20) | 0.03 | 0.2 | |
| Sm2Co17 151/159 | S20 | 870-930 (8.7-9.3) | ≥653 (≥8.2) | ≥1592 (≥20) | 151-175 (19-22) | 0.03 | 0.2 | |
| Sm2Co17 159/159 | S22 | 910-980 (9.1-9.8) | ≥693 (≥8.7) | ≥1592 (≥20) | 159-183 (20-23) | 0.03 | 0.2 | |
| Sm2Co17 175/159 | S24 | 960-1030 (9.6-10.3) | ≥724 (≥9.1) | ≥1592 (≥20) | 175-199 (22-25) | 0.03 | 0.2 | |
| Sm2Co17 191/159 | S26 | 1010-1060 (10.1-10.6) | ≥733 (≥9.2) | ≥1592 (≥20) | 191-215 (24-27) | 0.03 | 0.2 | |
| Sm2Co17 207/159 | S28 | 1040-1090 (10.4-10.9) | ≥749 (≥9.4) | ≥1592 (≥20) | 207-231 (26-29) | 0.03 | 0.2 | |
| Sm2Co17 222/159 | S30 | 1080-1110 (10.8-11.1) | ≥773 (≥9.7) | ≥1592 (≥20) | 222-247 (28-31) | 0.035 | 0.2 | |
| Sm2Co17 231/159 | S32 | 1100-1130 (11.2-11.5) | ≥804 (≥10.2) | ≥1592 (≥20) | 231-255 (29-32) | 0.038 | 0.2 | |
| Sm2Co17 239/159 | S33 | 1120-1160 (11.2-11.6) | ≥812 (≥10.2) | ≥1592 (≥20) | 239-263 (30-33) | 0.038 | 0.2 | |
| Sm2Co17 247/159 | S34 | 1150-1180 (11.5-11.8) | ≥835 (≥10.5) | ≥1592 (≥20) | 247-270 (31-34) | 0.04 | 0.25 | |
| Sm2Co17 255/159 | S35 | 1170-1200 (11.7-12.0) | ≥860 (≥10.8) | ≥1592 (≥20) | 255-278 (32-35) | 0.04 | 0.25 | |
| Sm2Co17 175/80 | S24M | 960-1030 (9.6-10.3) | 597-756 (7.5-9.5) | 796-1273 (10-16) | 175-199 (22-25) | 0.03 | 0.2 | |
| Sm2Co17 191/80 | S26M | 1010-1060 (10.1-10.6) | 597-820 (7.5-10.3) | 796-1273 (10-16) | 191-215 (24-27) | 0.03 | 0.2 | |
| Sm2Co17 207/80 | S28M | 1040-1090 (10.4-10.9) | 621-836 (7.8-10.5) | 796-1273 (10-16) | 207-231 (26-29) | 0.03 | 0.2 | |
| Sm2Co17 222/80 | S30M | 1080-1110 (10.8-11.1) | 621-836 (7.8-10.5) | 796-1273 (10-16) | 222-247 (28-31) | 0.035 | 0.2 | |
| Sm2Co17 239/80 | S32M | 1110-1150 (11.1-11.5) | 717-844 (9.0-10.6) | 796-1273 (10-16) | 239-263 (30-33) | 0.038 | 0.2 | |
| Sm2Co17 175/44 | S24L | 960-1030 (9.6-10.3) | 438-716 (5.5-9) | 478-796 (6-10) | 175-199 (22-25) | 0.03 | 0.2 | |
| Sm2Co17 191/44 | S26L | 1010-1060 (10.1-10.6) | 438-716 (5.5-9) | 478-796 (6-10) | 191-215 (24-27) | 0.03 | 0.2 | |
| Sm2Co17 207/44 | S28L | 1040-1090 (10.4-10.9) | 438-716 (5.5-9) | 478-796 (6-10) | 207-231 (26-29) | 0.03 | 0.2 | |
| Sm2Co17 222/44 | S30L | 1080-1120 (10.8-11.2) | 438-757 (5.5-9.5) | 478-796 (6-10) | 222-247 (28-31) | 0.035 | 0.2 | |
| Sm2Co17 231/44 | S32L | 1110-1150 (11.1-11.5) | 438-757 (5.5-9.5) | 478-796 (6-10) | 231-255 (29-32) | 0.038 | 0.2 | |
| Sm2Co17 151/199 | HTS20H | 870-930 (8.7-9.3) | ≥653 (≥8.2) | ≥1990 (≥25) | 151-175 (19-22) | 0.05 | 0.2 | |
| Sm2Co17 159/199 | HTS22H | 910-980 (9.1-9.8) | ≥693 (≥8.7) | ≥1990 (≥25) | 159-183 (20-23) | 0.05 | 0.2 | |
| Sm2Co17 175/199 | HTS24H | 960-1030 (9.6-10.3) | ≥724 (≥9.1) | ≥1990 (≥25) | 175-199 (22-25) | 0.05 | 0.2 | |
| Sm2Co17 103/159 | LTS14 | 730-800 (7.3-8.0) | ≥565 (≥7.1) | ≥1592 (≥20) | 103-127 (13-16) | 0.005 (20°C-100°C)0.01 (20°C-200°C) | 0.3 | |
| Sm2Co17 119/159 | LTS16 | 790-860 (7.9-8.6) | ≥613 (≥7.7) | ≥1592 (≥20) | 119-143 (15-18) | 0.01 (20°C-100°C) 0.015 (20°C-200°C) | 0.3 | |
| Sm2Co17 135/159 | LTS18 | 830-890 (8.3-8.9) | ≥645 (≥8.1) | ≥1592 (≥20) | 135-159 (17-20) | 0.015 (20°C-100°C) 0.02 (20°C-200°C) | 0.3 | |
| Sm2Co17 151/159 | LTS20 | 870-930 (8.7-9.3) | ≥653 (≥8.2) | ≥1592 (≥20) | 151-175 (19-22) | 0.02 (20°C-100°C) 0.025 (20°C-200°C) | 0.3 | |
| Sm2Co17 16/159 | QS4 | 300-500 (3.0-5.0) | ≥175 (≥2.2) | ≥1592 (≥20) | 16-48 (2-6) | 0.03 | 0.2 | |
| Sm2Co17 32/159 | QS6 | 500-700 (5.0-7.0) | ≥287 (≥3.6) | ≥1592 (≥20) | 32-96 (4-12) | 0.03 | 0.2 | |
| RECo5 119/199 | PS16H | 790-860 (7.9-8.6) | ≥605 (≥7.6) | ≥1990 (≥25) | 119-143 (15-18) | 0.05 | 0.3 | |
| RECo5 135/199 | PS18H | 840-910 (8.4-9.1) | ≥645 (≥8.1) | ≥1990 (≥25) | 135-159 (17-20) | 0.05 | 0.3 | |
| RECo5 151/199 | PS20H | 870-930 (8.7-9.3) | ≥653 (≥8.2) | ≥1990 (≥25) | 151-175 (19-22) | 0.05 | 0.3 | |
| RECo5 159/199 | PS22H | 910-980 (9.1-9.8) | ≥693 (≥8.7) | ≥1990 (≥25) | 159-183 (20-23) | 0.05 | 0.3 | |
| RECo5 175/199 | PS24H | 950-1010 (9.5-10.1) | ≥717 (≥9.0) | ≥1990 (≥25) | 175-199 (22-25) | 0.05 | 0.3 | |
| RECo5 111/159 | PS14 | 710-830 (7.1-8.3) | ≥541 (≥6.8) | ≥1592 (≥20) | 95-127 (12-16) | 0.05 | 0.3 | |
| RECo5 119/159 | PS16 | 790-860 (7.9-8.6) | ≥605 (≥7.6) | ≥1592 (≥20) | 119-143 (15-18) | 0.05 | 0.3 | |
| RECo5 135/159 | PS18 | 840-910 (8.4-9.1) | ≥645 (≥8.1) | ≥1592 (≥20) | 135-159 (17-20) | 0.05 | 0.3 | |
| RECo5 151/159 | PS20 | 870-930 (8.7-9.3) | ≥653 (≥8.2) | ≥1592 (≥20) | 151-175 (19-22) | 0.05 | 0.3 | |
| RECo5 159/159 | PS22 | 910-980 (9.1-9.8) | ≥693 (≥8.7) | ≥1592 (≥20) | 159-183 (20-23) | 0.05 | 0.3 | |
| RECo5 175/159 | PS24 | 950-1010 (9.5-10.1) | ≥717 (≥9.0) | ≥1592 (≥20) | 175-199 (22-25) | 0.05 | 0.3 |
Common Shapes of Samarium Cobalt Magnets
Samarium Cobalt Arc Magnets
Samarium Cobalt Block Magnets
Samarium Cobalt Disc Magnets
Samarium Cobalt Ring Magnets
Samarium Cobalt Magnet Assemblies
Samarium Cobalt magnet assemblies combine Samarium Cobalt magnets with shafts, housings, sleeves, carriers, or other functional parts to create integrated magnetic components for specific applications. For projects that require better dimensional consistency, reduced assembly complexity, or closer coordination between magnetic performance and mechanical structure, this route can be more practical than sourcing raw magnets alone.
SmCo Magnet Assemblies
Magnetization Directions of Samarium Cobalt Magnets
Samarium Cobalt magnets require a stronger external magnetic field for saturation than Neodymium magnets, especially high-coercivity Sm2Co17 magnets. For this reason, they are typically magnetized by fast impulse magnetization before being used in their final applications. Magnetizing Samarium Cobalt magnets also requires magnetizing equipment with sufficient capacity to generate the necessary field strength.
Samarium Cobalt magnets have a preferred magnetization direction, and different pole configurations can be achieved as long as they do not conflict with the preset orientation direction. In practical applications, however, the design and capability of the magnetizing fixture often become the key factors that limit the achievable multipole magnetization pattern.
Axial Magnetization
Diametrical Magnetization
Radial Magnetization
Diametrical Multipole Magnetization
Applications of Samarium Cobalt Magnets
Samarium Cobalt magnets are widely used in demanding applications that require high magnetic performance, excellent temperature stability, and long-term reliability. They are especially suitable for products and systems operating in harsh environments where corrosion resistance and stable magnetic output are critical.
Medical Devices
Aerospace Systems
Industrial Automation
Automotive Sensors
Energy & Power
Scientific Instruments
How to Choose the Right Samarium Cobalt Magnet
Choosing the right Samarium Cobalt magnet depends on several factors, including the required magnetic output, operating temperature, magnet shape, dimensional requirements, and magnetization direction. In many cases, magnetic performance, temperature capability, and corrosion resistance should be considered together during the selection process.
It is also important to determine whether SmCo5 or Sm2Co17 is more suitable for the application. SmCo5 magnets are generally easier to machine, while Sm2Co17 magnets are often selected when higher magnetic performance and more demanding high-temperature performance are required. Mechanical limitations, assembly conditions, and cost considerations may also affect the final choice.
If you need help selecting the right grade, material system, shape, or magnetization direction, feel free to contact us for technical support and product recommendations.
Export Control Support for Samarium Cobalt Magnets
For projects involving export-controlled Samarium Cobalt magnets from China, planning the right supply path early can save time and reduce uncertainty. We aim to help customers move projects forward more smoothly by reviewing the application scenario, clarifying documentation needs, and discussing workable supply options at an early stage.
We have already been following these changes closely and continue to update related progress on our website as policies, licensing practices, and supply-chain conditions evolve. For some projects, supplying a finished magnetic assembly rather than raw magnet material may be a more practical option, especially when a clearer end-use presentation is important.
If you are sourcing Samarium Cobalt magnets from China, contact us early to discuss your application, documentation path, and whether a finished magnetic assembly may be the better solution for your project.
SmCo Resources & Specifications
SmCo Product Catalog
Complete SmCo₅ and Sm₂Co₁₇ specifications, shapes, and ordering information.
Specify Your High-Temperature Magnet Application
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