Aerospace actuators and sensors
Thermal stability, demagnetization margin and program qualification.
SmCo Magnets — Stability at Extreme Temperatures
Samarium cobalt maintains its magnetic properties where NdFeB surrenders: up to 350°C, in corrosive environments, and under long-term demagnetizing stress. SmCo 1:5 and 2:17 series for aerospace, automotive, and industrial applications.
For Procurement
MOQ, lead time, packaging and commercial terms — go straight to a quotation.
Request a Quote →For Engineering
Grades, drawings, process data and design support for your DFM review.
Grade Datasheets & Technical Data →For Quality / SQE
Certificates, inspection planning, traceability and PPAP / FAI support per project.
Certificates & Documentation →Magnetic Performance at a Glance
Product Range
SmCo Magnets — Product Gallery
Representative product forms for reference. Final geometry, material and finish are agreed for each project.
Why SmCo?
When your application runs hot, corrosive, or demands decades of stable flux output, SmCo is worth the premium over NdFeB.
- ✓Superior temperature stability — reversible temperature coefficient of -0.03%/°C (2:17) vs NdFeB's -0.12%/°C
- ✓No coating required — intrinsic corrosion resistance eliminates coating failure as a reliability risk
- ✓High coercivity — excellent resistance to demagnetization from external fields and recoil
- ✓Linear demag curve — predictable behavior at elevated temperatures, simplifying circuit design
Applications
| Application | Typical Spec | Why This Material |
|---|---|---|
| Aerospace & Defense | SmCo 2:17 S24H–S30H | Reliable flux at 300°C+ in actuators, TWTs |
| 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 | Biocompatible, no coating to degrade |
Standard SmCo Grades
12 grade datasheets in our download library.
| Grade | Series | Max Energy Product | Br (kGs) | iHc (kOe) | Max Temp | Best For |
|---|---|---|---|---|---|---|
| S22H | 2:17 | 20–24 MGOe | 10.2–10.8 | ≥25 | 300°C | General high-temp |
| S26H | 2:17 | 24–28 MGOe | 11.0–11.5 | ≥25 | 300°C | High performance |
| S30H | 2:17 | 28–32 MGOe | 11.8–12.4 | ≥25 | 300°C | Premium grade |
| HTS22H | 2:17 | 20–24 MGOe | 10.2–10.8 | ≥25 | 350°C | Extreme temperature |
| S24H (1:5) | 1:5 | 20–26 MGOe | 10.2–10.8 | ≥30 | 250°C | High coercivity, fine grain |
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 — only grinding; no drilling, tapping, or turning — design net-shape or add machinable features
- ✓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
Complete Technical Data
Full reference tables for Samarium Cobalt (SmCo) Magnets — migrated from our production specification library. Click any row's PDF to download the grade datasheet.
Data table 1
| 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 |
Data table 2
| 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 |
Application Engineering
Where SmCo magnets Fit
Typical component uses and the requirements to discuss before quotation. Suitability depends on your design and validation criteria.
High-temperature automotive systems
Hot operating conditions, corrosion exposure and retention method.
Precision medical equipment
Field consistency, geometry and device-specific requirements.
Scientific instrumentation
Field stability, temperature range and measurement conditions.
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 guide →Frequently 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. For most environments, uncoated SmCo performs reliably for decades. 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 grinds cleanly — tighter tolerances cost less than on NdFeB in many cases:
| 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.
Production & Supply Planning
SmCo Magnets: A Defined Route to Repeat Orders
Agree the process, acceptance criteria and shipment plan before production starts. The quotation identifies the producing site and the controls required for your part.
Confirm the manufacturing route
Confirm SmCo5 or Sm2Co17 grade, geometry, thermal duty and the forming, sintering and machining route.
Approve the inspection plan
Agree magnetic performance, dimensions, thermal requirements and brittle-edge acceptance criteria.
Qualify before repeat supply
Define sample approval, drawing revision and lot identification. Agree how material, process or site changes will be reviewed before implementation.
Plan releases and delivery
Confirm order quantities, capacity allocation, packaging and shipping terms against your forecast. Delivery dates and any buffer-stock arrangement belong in the agreed supply plan.
Have a Drawing or Specification?
Send it to our team for engineering review and quotation — grade recommendation included.