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Samarium cobalt (SmCo) is a permanent-magnet family commonly considered when an application needs magnetic performance at elevated temperature. SmCo₅ and Sm₂Co₁₇ grades differ in remanence, coercivity and temperature behavior.
There is no single operating-temperature limit for all SmCo magnets. Share the maximum continuous and peak temperatures, working point, dimensions and required field so the proposed grade can be checked against its datasheet and assembly conditions. See Arnold Magnetic Technologies’ grade-specific reference for an example of how maximum operating temperatures vary by grade.
SmCo₅ is a samarium-cobalt magnet family with an approximate 1:5 samarium-to-cobalt composition. Specific commercial grades may use other additions, so composition and magnetic properties should be checked against the proposed grade datasheet.
The table below is a reference for comparing grades, not a blanket operating limit for a finished part. Temperature suitability depends on grade, magnet geometry, magnetic working point and the assembly. SmCo is brittle; thin walls, holes and sharp edges need a drawing review for machining and handling. For a quote, include dimensions and tolerances, magnetization direction, required field, continuous and peak temperature, environment, quantity and inspection criteria.
| Grade | Remanence/Br. | Coercivity Force/HcB. | Intrinsic Coercivity/HcJ. | Maximun Energy/(BH)max | Curie Temperature | Max. Operating Temperature | Temperature Coefficient of Br α(Br) | Temperature Coefficient of Hcj β(Hcj) | ||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| T | KGs | KA/m | KOe | KA/m | KOe | KJ/m3 | MGOe | ℃ | ℃ | ％/℃ | ％/℃ | |
| YX-16s | 0.79-0.84 | 7.9-8.4 | 620-660 | 7.8-8.3 | ≥1830 | ≥23 | 118-135 | 15-17 | 750 | 250 | -0.035 | -0.28 |
| YX-18s | 0.84-0.89 | 8.4-8.9 | 660-700 | 8.3-8.8 | ≥1830 | ≥23 | 135-151 | 17-19 | 750 | 250 | -0.04 | -0.28 |
| YX-20s | 0.89-0.93 | 8.9-9.3 | 684-732 | 8.6-9.2 | ≥1830 | ≥23 | 150-167 | 19-21 | 750 | 250 | -0.045 | -0.28 |
| YX-22s | 0.92-0.96 | 9.2-9.6 | 710-756 | 8.9-9.5 | ≥1830 | ≥23 | 167-183 | 21-23 | 750 | 250 | -0.045 | -0.28 |
| YX-24s | 0.96-1.00 | 9.6-10.0 | 740-788 | 9.3-9.9 | ≥1830 | ≥23 | 183-199 | 23-25 | 750 | 250 | -0.045 | -0.28 |
| LTC (YX-10) (SmGd)Co5 | 0.62-0.66 | 6.2-6.6 | 485-517 | 6.1-6.5 | ≥1830 | ≥23 | 75-88 | 9.5-11 | 750 | 300 | Temp. Range 20-100℃ 100-200℃ 200-300℃ | α(Br) +0.0156+0.0087 +0.0007 |
| The temperature coefficients of remanence Br and intrinsic coercivity Hcj are measured at 20°C to 150°C, only for reference. | ||||||||||||
| Theoretical calculation formula (T1 = room temperature (usually 20℃), T2=high temperature): | ||||||||||||
| Br@T2=Br@T1-[(T2-T1)*α(Br)*Br@T1] | ||||||||||||
| Hcj@T2=Hcj@T1-[(T2-T1)*β(Hcj)*Hcj@T1] | ||||||||||||
| Taking YX-20s，Br=0.9T, Hcj=1830KA/m as an example, the theoretical value at 150℃ is calculated as follows: | ||||||||||||
| Br@150℃=0.9-[(150-20)*0.045%*0.9]=0.8473T | ||||||||||||
| Hcj@150℃=1830-[(150-20)*0.28%*1830]=1163.88KA/m | ||||||||||||
| Sm₁Co₅ | Unit | SmCo5 Magnet |
|---|---|---|
| Density (D) | G/Cm3 | 8.3 |
| Curie Temperature (Tc) | K | 1000 |
| Vickers Hardness (Hv) | MPa | 450-500 |
| Compressive Strength (δc) | MPa | 1000 |
| Resistivity (ρ) | Ω.Cm | 5～6×10⁻⁵ |
| Bending Strength (δb) | Mpa | 150-180 |
| Tensile Strength (δt) | Mpa | 40 |
| Coeff. of Thermal Expansion (α) | (10⁻⁶/℃) | ∥ 6 |
Sm₂Co₁₇ is a samarium-cobalt magnet family. Grade formulations commonly include iron, copper and zirconium, but composition and magnetic properties vary by grade. The grade table below is a comparison reference; its values do not guarantee the performance or temperature limit of every finished part.
Check the proposed grade datasheet at the actual magnetic working point and continuous and peak temperatures. SmCo is brittle, so thin walls, holes, sharp corners and handling requirements should be reviewed against the drawing. Specify dimensions, tolerances, magnetization direction, required field, temperature profile, environment, quantity and inspection method when requesting a quote.
| Grade | Remanence/Br | Coercivity Force/HcB | Intrinsic Coercivity/HcJ | (BH)max Maximun Energy | Curie Temperature | Max. Operating Temperature | Temperature Coefficient of Br α(Br) | Temperature Coefficient of Hcj β(Hcj) | ||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| T | KGs | KA/m | KOe | KA/m | KOe | KJ/m3 | MGOe | ℃ | ℃ | ％/℃ | ％/℃ | |
| YXG-24H | 0.95-1.02 | 9.5-10.2 | 692-764 | 8.7-9.6 | ≥1990 | ≥25 | 175-191 | 22-24 | 800 | 350 | -0.035 | -0.2 |
| YXG-26H | 1.02-1.05 | 10.2-10.5 | 748-796 | 9.4-10.0 | ≥1990 | ≥25 | 191-207 | 24-26 | 800 | 350 | -0.035 | -0.2 |
| YXG-28H | 1.03-1.08 | 10.3-10.8 | 756-812 | 9.5-10.2 | ≥1990 | ≥25 | 207-223 | 26-28 | 800 | 350 | -0.035 | -0.2 |
| YXG-30H | 1.08-1.10 | 10.8-11.0 | 788-835 | 9.9-10.5 | ≥1990 | ≥25 | 223-239 | 28-30 | 800 | 350 | -0.035 | -0.2 |
| YXG-32H | 1.10-1.13 | 11.0-11.3 | 812-860 | 10.2-10.8 | ≥1990 | ≥25 | 231-255 | 29-32 | 800 | 350 | -0.035 | -0.2 |
| YXG-33H | 1.12-1.16 | 11.2-11.6 | 845-890 | 10.6-11.2 | ≥1990 | ≥25 | 239-263 | 30-33 | 800 | 350 | -0.035 | -0.2 |
| YXG-22 | 0.93-0.97 | 9.3-9.7 | 676-740 | 8.5-9.3 | ≥1433 | ≥18 | 160-183 | 20-23 | 800 | 300 | -0.035 | -0.2 |
| YXG-24 | 0.95-1.02 | 9.5-10.2 | 692-764 | 8.7-9.6 | ≥1433 | ≥18 | 175-191 | 22-24 | 800 | 300 | -0.035 | -0.2 |
| YXG-26 | 1.02-1.05 | 10.2-10.5 | 748-796 | 9.4-10.0 | ≥1433 | ≥18 | 191-207 | 24-26 | 800 | 300 | -0.035 | -0.2 |
| YXG-28 | 1.03-1.08 | 10.3-10.8 | 756-812 | 9.5-10.2 | ≥1433 | ≥18 | 207-223 | 26-28 | 800 | 300 | -0.035 | -0.2 |
| YXG-30 | 1.08-1.10 | 10.8-11.0 | 788-835 | 9.9-10.5 | ≥1433 | ≥18 | 223-239 | 28-30 | 800 | 300 | -0.035 | -0.2 |
| YXG-32 | 1.10-1.13 | 11.0-11.3 | 812-860 | 10.2-10.8 | ≥1433 | ≥18 | 231-255 | 29-32 | 800 | 300 | -0.035 | -0.2 |
| YXG-33 | 1.12-1.16 | 11.2-11.6 | 845-890 | 10.6-11.2 | ≥1433 | ≥18 | 239-263 | 30-33 | 800 | 300 | -0.035 | -0.2 |
| YXG-35 | 1.16-1.2 | 11.6-12.0 | 868-908 | 10.9-11.4 | ≥1433 | ≥18 | 255-278 | 32-35 | 800 | 300 | -0.035 | -0.25 |
| YXG-26M | 1.02-1.05 | 10.2-10.5 | 676-780 | 8.5-9.8 | 955-1433 | 45278 | 199-215 | 25-27 | 800 | 300 | -0.035 | -0.2 |
| YXG-28M | 1.03-1.08 | 10.3-10.8 | 676-796 | 8.5-10.0 | 955-1433 | 45278 | 207-220 | 26-28 | 800 | 300 | -0.035 | -0.2 |
| YXG-30M | 1.08-1.10 | 10.8-11.0 | 676-835 | 8.5-10.5 | 955-1433 | 45278 | 220-240 | 28-30 | 800 | 300 | -0.035 | -0.2 |
| YXG-32M | 1.10-1.13 | 11.0-11.3 | 676-852 | 8.5-10.7 | 955-1433 | 45278 | 230-255 | 29-32 | 800 | 300 | -0.035 | -0.2 |
| YXG-24L | 0.95-1.02 | 9.5-10.2 | 541-716 | 6.8-9.0 | 636-955 | 45150 | 183-199 | 23-25 | 800 | 250 | -0.035 | -0.2 |
| YXG-26L | 1.02-1.05 | 10.2-10.5 | 541-748 | 6.8-9.4 | 636-955 | 45150 | 199-215 | 25-27 | 800 | 250 | -0.035 | -0.2 |
| YXG-28L | 1.03-1.08 | 10.3-10.8 | 541-764 | 6.8-9.6 | 636-955 | 45150 | 207-220 | 26-28 | 800 | 250 | -0.035 | -0.2 |
| YXG-30L | 1.08-1.15 | 10.8-11.5 | 541-796 | 6.8-10.0 | 636-955 | 45150 | 220-240 | 28-30 | 800 | 250 | -0.035 | -0.2 |
| YXG-32L | 1.10-1.15 | 11.0-11.5 | 541-812 | 6.8-10.2 | 636-955 | 45150 | 230-255 | 29-32 | 800 | 250 | -0.035 | -0.2 |
| LTC(YXG-18) | 0.84-0.89 | 8.4-8.9 | 629-668 | 7.9-8.4 | ≥1433 | ≥18 | 135-151 | 17-19 | 840 | 300 | -0.001 | -0.25 |
| LTC(YXG-20) | 0.89-0.94 | 8.9-9.4 | 660-708 | 8.3-8.9 | ≥1433 | ≥18 | 151-167 | 19-21 | 840 | 300 | -0.007 | -0.25 |
| LTC(YXG-22) | 0.94-0.98 | 9.4-9.8 | 692-740 | 8.7-9.3 | ≥1433 | ≥18 | 167-183 | 21-23 | 840 | 300 | -0.01 | -0.25 |
| HT400(YXG-26) | 0.99-1.04 | 9.9-10.4 | 740-812 | 9.3-10.2 | ≥1830 | ≥23 | 191-215 | 24-27 | 850 | 400 | -0.035 | -0.12 |
| HT450(YXG-24) | 0.96-0.99 | 9.6-9.9 | 724-772 | 9.1-9.7 | ≥1830 | ≥23 | 175-199 | 22-25 | 850 | 450 | -0.035 | -0.12 |
| HT500(YXG-22) | 0.93-0.97 | 9.3-9.7 | 708-756 | 8.9-9.5 | ≥1830 | ≥23 | 160-183 | 20-23 | 850 | 500 | -0.035 | -0.12 |
| The temperature coefficients of remanence Br and intrinsic coercivity Hcj are measured at 20°C to 150°C, only for reference. | ||||||||||||
| Theoretical calculation formula (T1 = room temperature (usually 20℃), T2=high temperature): | ||||||||||||
| Br@T2=Br@T1-[(T2-T1)*α(Br)*Br@T1] | ||||||||||||
| Hcj@T2=Hcj@T1-[(T2-T1)*β(Hcj)*Hcj@T1] | ||||||||||||
| Taking YXG-28H, Br=1.03T, Hcj=1990KA/m as an example, the theoretical value at 150℃ is calculated as follows: | ||||||||||||
| Br@150℃=1.03-[(150-20)*0.035%*1.03]=0.9831T | ||||||||||||
| Hcj@150℃=1990-[(150-20)*0.2%*1990]=1472KA/m | ||||||||||||
| Sm₂Co₁₇ Magnet | Unit | Result |
|---|---|---|
| Density (D) | G/Cm3 | 8.4 |
| Curie Temperature (Tc) | K | 1100 |
| Vickers Hardness (Hv) | MPa | 550-600 |
| Compressive Strength (δc) | MPa | 800 |
| Resistivity (ρ) | Ω.Cm | 8～9× 10⁻⁵ |
| Bending Strength (δb) | Mpa | 130-150 |
| Tensile Strength (δt) | Mpa | 35 |
| Coeff. of Thermal Expansion (α) | ( 10⁻⁶/℃) | ∥ 8 |
| ⊥11 |
SmCo grades can offer useful magnetic stability at elevated temperature, but service limits and corrosion behavior depend on the selected grade, finish and operating environment. A published material table is a starting point for review, not a guaranteed limit for every shape or assembly.
For a custom SmCo quote, provide the drawing, SmCo₅ or Sm₂Co₁₇ preference if known, required field at the working gap, continuous and peak temperature, environment, magnetization direction, quantity and inspection criteria. Magnetstek can review the applicable grade and supply scope for that inquiry.
Browse listed SmCo disc products; current grade, stock status and delivery are confirmed with the quote.
The range of SmCo magnet grade ranged from 16 MGOe to 32 MGOe. The various grades can support industrial and commercial applications with operational temperature resistance, magnetic performance, and budget balance.
There are two types of SmCo magnets with different samarium and cobalt atomic ratios: Sm₁Co₅ and Sm₂Co₁₇.
The magnetization direction sets the orientation of the field and should be marked on the finished-part drawing. It affects the field available at the working position. Include the operating gap and any field or pull-force test method when requesting a quote.
Common magnetization directions for rare earth magnets include:
Discs & Cylinders
Disc and cylinder magnets can be specified with axial or diametric magnetization, subject to geometry and tooling review.
Rings&Tubes
Rings and tubes like discs and cylinders can be axially or diametrically magnetized.
Blocks&Cubes
Block magnets are characterized by their three dimensions: length, width, and thickness. We are occasionally asked if we can provide magnetized block magnets through their length or width. The answer is yes; some long “bar” magnets are magnetized in their longest dimension.
Arc Segments
Arc segments have usually been magnetized in pairs, SN-NS. So that they can be assembled to one ring on a rotor, there are two other possible magnetization directions.
Special Magnetization
For spherical magnets, show the intended pole axis in the assembly. For mounting assemblies, show which face needs the working field and any required pole pattern. Magnetization feasibility is confirmed against the specific geometry and fixture.
Multi-Pole Magnetization
Multi-pole magnetization places alternating poles around or across a part. State the pole count, pitch, layout and required field at the working position. Feasibility depends on the material, dimensions and magnetizing fixture.
Radial Magnetization
A ring shape alone does not specify radial magnetization. Show the required field direction, whether the useful field is inside or outside the ring, and any pole pattern on the drawing. The geometry and tooling should be reviewed before quotation.
For a custom SmCo part, mark the required magnetization direction and pole faces on the drawing. Axial, diametric and multipole arrangements serve different magnetic circuits; the best choice depends on the field needed at the working gap, the mating components and the assembly geometry. Include any required field or polarity test so the proposed direction can be checked before quotation.
Whether an SmCo part needs a coating depends on the grade, operating environment, cleanliness requirement and mating components. Resistance to ordinary atmospheric corrosion does not establish suitability for acids, salt exposure, sterilization or bodily contact.
If a coating or encapsulation is required, specify its material, thickness, coverage, dimensional allowance and inspection test on the drawing. Medical or aerospace use requires application-specific material and device validation; a coating name alone does not establish approval. Magnetstek can review coating availability and the applicable supply scope with the drawing and acceptance requirements.
While strong rare earth magnets, such as NdFeB and SmCo magnets, are widely used for various applications due to their strong magnetic properties, it is essential to be aware of safety considerations when handling these magnets.
Here are some essential safety guidelines:
Rare earth magnets, such as neodymium and samarium cobalt magnets, are powerful, and if they come together suddenly, they can cause injuries. Be cautious of fingers or other body parts getting caught between attracting magnets.
With large magnets, severe injuries can be caused.
Rare earth magnets are not toys. Children should not be allowed to handle strong magnets. Choking small magnets or playing with large magnets are equally dangerous to children. If multiple magnets are swallowed, they can attach through intestine walls. This can cause a severe health risk, requiring immediate, emergency surgery if correctly diagnosed.
The strong magnetic fields near a neodymium or samarium cobalt magnet can affect pacemakers, ICDs, and other implanted medical devices. Therefore, you must take care to avoid inadvertently deactivating such devices.
Some people may have a nickel allergy, where an allergic reaction can cause redness and a skin rash. These people should avoid prolonged contact with nickel-coated magnets.
Strong magnets can interfere with electronic devices like credit cards, magnetic I.D. cards, VCRs, cassette tapes, floppy disks, and hard drives. Keep strong magnets away from these devices to prevent potential damage.
Magnetic fields can influence compasses or magnetometers used in air transport. They can also affect the internal compasses of smartphones and GPS devices. IATA (International Air Transport Association) and US Federal rules and regulations cover shipping magnets by air and ground delivery.
Rare earth magnets are made of hard and brittle material. They are not as durable as steel, even if they look like steel. Magnets can chip, peel, crack, or shatter if they are slammed together. Eye protection should be worn when handling magnets.
Rare earth magnets can not easily be re-machined.
Rare earth magnets, especially Neodymium magnets, can become demagnetized at high temperatures. You should know the magnet grade and the maximum operating temperature. A magnet should be stored and used below the maximum temperature.
Though most magnets are coated and protected, they are still not waterproof. In humid environments or even water, neodymium magnets can rust or corrode and lose magnetic strength.
*The icons used on this page are derivative works based on icons by Freepik from www.flaticon.com, licensed by CC BY 3.0.
Handling SmCo magnets carefully is essential, as they are brittle and break easily. Additionally, precautions should be taken to avoid situations where the magnets could pose a danger, such as swallowing, as they can be hazardous if ingested.
Always keep away from pacemakers and children.
SmCo magnets find wide-ranging applications in various industries, including aerospace, defense, transportation, and communication, specifically:
Share your drawing, magnetic requirements and operating conditions. Magnetstek reviews grade, coating, magnetization and inspection options for each custom part.
