Aerospace & Defense
SmCo 2:17 S24H–S30H
Reliable flux at 300°C+ in actuators, TWTs
Samarium Cobalt Magnets
Samarium cobalt magnets for temperature-sensitive magnetic circuits. Compare 1:5 and 2:17 materials, shapes and complete grade data.
SmCo 1:5 vs 2:17
The two SmCo series offer different balances of cost, performance, and processability:
- ✓SmCo 1:5 (SmCo₅) — higher coercivity, easier to magnetize to saturation, better for small/complex parts
- ✓SmCo 2:17 (Sm₂Co₁₇) — higher energy product, better temperature coefficient, more cost-efficient
- ✓Our recommendation — most applications today use 2:17 for its better performance-cost balance; 1:5 remains preferred for very small parts and fine-grain requirements
Working with SmCo
SmCo is brittle — design and handle accordingly:
- ✓Machining — grinding and specialist cutting are used for this brittle material; review holes and mounting features before choosing a manufacturing route
- ✓Chamfers — specify edge chamfers to prevent chipping during handling and assembly
- ✓Assembly — use non-magnetic tooling and careful press-fits; SmCo chips easily under point loads
- ✓Testing — we verify flux and BH-curve on every production lot per your sampling plan
Product Range
SmCo Magnets — Product Gallery
Product forms, uses and selection considerations. Final specifications are agreed for each project.
Custom SmCo Shapes
Geometry and grade selected for thermal stability.
Arc Segments
Curved segments for motors and magnetic couplings.
Small Precision Parts
Small-format parts with drawing-defined inspection requirements.
Connect Temperature to the Magnetic Circuit
Review the 1:5 and 2:17 grade families against the operating temperature and magnetic circuit; the material name alone does not define the service limit.
The block, ring and arc forms illustrate geometry choices. Specify edge breaks, machining tolerances and handling constraints for this brittle material.
Review SmCo grade families- Continuous/peak temperature and thermal cycling
- Magnetic acceptance at the defined gap and temperature
- Edge quality, handling and assembly loading
Thermal Stability, Defined by the Design
Review operating temperature, opposing field and geometry together when selecting a SmCo grade.
SELECTION GUIDEApplication selection notesExplore applications and requirements
Why SmCo?
SmCo is selected where thermal stability and resistance to demagnetization are central to the design. Compare the 1:5 and 2:17 families, then review the operating point and mechanical requirements for your component.
- ✓Superior temperature stability — reversible temperature coefficient of -0.03%/°C (2:17) vs NdFeB's -0.12%/°C
- ✓Corrosion-resistant material — coating may be unnecessary in suitable environments; aggressive media, cleanliness and particle-shedding requirements can still call for surface protection
- ✓High coercivity — excellent resistance to demagnetization from external fields and recoil
- ✓Linear demag curve — predictable behavior at elevated temperatures, simplifying circuit design
Applications
Automotive Sensors
SmCo 2:17 S22H
Stable output across -40°C to 180°C engine bay
Oil & Gas Downhole
SmCo 2:17 HTS24
High temp + corrosive fluids
Microwave Tubes
SmCo 1:5 S22H
Stable field for traveling wave tubes
Medical Devices
SmCo 2:17 S26H
Material and coating suitability must be reviewed against the device, contact conditions and project documentation.
Application examples are selection references. Validate temperature, magnetic circuit, corrosion protection and acceptance conditions for the actual assembly.
Aerospace & defense project enquiries Supplier documentation
Grades & Technical Data
Use this single reference for grade properties, application notes and available datasheets. Confirm the selected specification with engineering before ordering.
Application Selection Notes
| Grade | Series | Temp. reference* | Typical application |
|---|---|---|---|
| S22H | 2:17 | 300°C | General high-temp |
| S26H | 2:17 | 300°C | High performance |
| S30H | 2:17 | 300°C | Premium grade |
| HTS22H | 2:17 | 350°C | Extreme temperature |
| S24H (1:5) | 1:5 | 250°C | High coercivity, fine grain |
*Temperature values are selection references, not part-specific limits. Confirm the grade, magnetic circuit and test conditions before specifying.
Family Property Reference
| 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 |
Complete Grade Directory
All published grades are available below. Filter by series or grade name, then select up to four entries to compare. Final selection requires review of the complete operating conditions.
Scroll to view more columns.
| 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 |
Engineering Guide
Magnet Grade & Temperature Selection
Compare SmCo with NdFeB, ferrite and AlNiCo using operating temperature, magnetic load line, corrosion and cost.
Read the selection guideFrequently Asked Questions
Why is SmCo more expensive than NdFeB?
Samarium is rarer than neodymium, and SmCo requires more cobalt — both driving raw material cost. However, SmCo needs no coating (saving finishing cost) and offers superior temperature stability. For applications above 150–200°C, SmCo's total cost of ownership is often lower than high-temp NdFeB grades that use expensive dysprosium additions.
Can SmCo work without coating?
Yes — SmCo has intrinsic corrosion resistance far superior to NdFeB. Uncoated use depends on the medium, temperature and required surface condition; service life must be evaluated for the application. In extreme salt-spray or acidic environments, we can apply Ni-Cu-Ni or epoxy for additional protection.
What temperature does SmCo actually handle?
Standard 2:17 grades are rated to 300°C; our HT (high-temperature) series reaches 350°C. Above 350°C, oxidation of the samarium accelerates and long-term stability requires careful evaluation. We test at your actual operating temperature during DFM review.
Is SmCo brittle?
Yes — SmCo is significantly more brittle than NdFeB and will chip or crack under impact or point loading. We recommend chamfered edges, protective packaging, and careful assembly procedures. Our DFM review includes handling recommendations specific to your geometry.
Available Geometries
We produce SmCo in standard and custom geometries — 1:5 and 2:17 series, matched to your magnetic circuit:
- ✓Discs & cylinders — axially or diametrically magnetized
- ✓Blocks & rectangles — as-sintered or ground on all faces
- ✓Rings — radial or axial, ID/OD ground for concentricity
- ✓Arcs & segments — motor poles, skewed on request
- ✓Custom shapes — machined to your drawing
Machining & Dimensional Tolerances
SmCo is brittle and requires controlled machining. Quote tolerances from the geometry, edge-quality requirements and inspection method:
| Process | Typical Tolerance | Notes |
|---|---|---|
| As-sintered | ±0.1 mm | Most economical; non-critical faces |
| Ground | ±0.05 mm | Standard for mating dimensions |
| Precision ground | ±0.02 mm | Press-fit diameters andlocating faces |
| Parallelism / perpendicularity | Per drawing | Confirmed during DFM review |
Test & Quality Documentation
What ships with your parts — scoped per project during quotation.
Magnetic Properties
Certificate of Analysis with measured Br / Hcb / Hcj / (BH)max against the specified grade of your SmCo parts, from our demagnetization-curve test equipment.
Dimensional Inspection
Dimensional reports by gauge or CMM as agreed in the inspection plan; critical dimensions identified together during DFM review.
Compliance & Project Docs
RoHS / REACH declarations on request, and FAI / PPAP documentation per project requirements.
Inspection Plan Agreement
Specify critical characteristics, sampling and acceptance criteria so the requested records match your part and application.
Plan the quality reviewProcess reference images are separated from the product gallery. They illustrate equipment and handling topics; they do not establish ownership of a facility, a customer delivery, or project-specific inspection results.
Factory Tour
Inside SmCo Magnets Manufacturing
SmCo5 and Sm2Co17 follow a specialist high-temperature powder-metallurgy route with composition control, vacuum processing and magnetic verification.
4 process viewsProduct-specific manufacturing
1 inspection viewRelevant quality equipment
1 packing viewProduct-appropriate protection
End-to-end process visibilityManufacturing · inspection · packing documented in one focused route
Manufacturing processInspection & testingPacking & dispatch
Grade-Specific Proportioning
Samarium, cobalt and alloy additions are weighed to the specified formulation.
Vacuum Alloy Melting
Controlled melting protects chemistry and limits contamination before powder preparation.
Fine Powder Preparation
Crushing and airflow milling control particle size before magnetic-field pressing.
Scaled Vacuum Sintering Hall
Rows of controlled-atmosphere vacuum furnaces support stable high-temperature sintering for SmCo production.
Hysteresis & Magnetic Curve Analysis
A vibrating-sample magnetometer characterizes coercivity, remanence and temperature-sensitive magnetic behavior.
Lot-Controlled SmCo Packing
Small brittle parts, inspection records and lot identification are secured together for shipment.
Manufacturing, inspection and packing photographs for this product family.Equipment route varies by material and geometryRemote video inspection available before shipment
Have a Drawing or Specification?
Send it to our team for engineering review and quotation — grade recommendation included.