Cost-efficient hard ferrite magnets for high-volume motors, speakers, separators and industrial applications, produced in rings, blocks, discs and dedicated arc segments.
Cost-efficient hard ferrite magnets for high-volume motors, speakers, separators and industrial applications, produced in rings, blocks, discs and dedicated arc segments.
Hard ferrite is a ceramic permanent magnet based primarily on strontium or barium ferrite. Its lower energy density is offset by very low material cost, intrinsic corrosion resistance and high electrical resistivity.
Economical route for discs, blocks and other simple geometries. Can be isotropic or field-oriented depending on the grade/process.
Slurry pressing in a magnetic field improves particle alignment and magnetic performance; often used for higher-performance anisotropic parts.
Dedicated segment production is used for DC motors, appliance motors and other radial-gap applications.
The ceramic oxide structure is intrinsically corrosion resistant; coatings are usually cosmetic or application-specific rather than mandatory.
| Application | Typical Spec | Why this material |
|---|---|---|
| DC / appliance motors | Y30 / Y30BH | Low cost and robust high-volume performance |
| Loudspeakers | Y25 / Y30 | Large magnet volume at economical cost |
| Magnetic separators | Y40 anisotropic | Higher ferrite energy for large field structures |
| Automotive sensing / small motors | Y30BH | Temperature-stable and corrosion-resistant |
| Consumer / crafts | Y10T isotropic | Low-cost geometry with flexible magnetization direction |
| Type | Orientation | Relative performance | Magnetization flexibility | Best fit |
|---|---|---|---|---|
| Isotropic | No preferred particle orientation | Lower | Can be magnetized in multiple directions | Cost-critical, multipole, consumer applications |
| Anisotropic | Particles aligned during pressing | Higher | Preferred direction fixed by manufacturing | Motors, speakers, separators |
| Wet-pressed anisotropic | Field-oriented slurry pressing | Highest mainstream ferrite performance | Preferred direction fixed | Higher-performance motor segments / rings |
Use the table as a selection reference. Final acceptance limits follow the approved drawing/specification and agreed test method.
| Grade | Br mT (kGs) | Hcb kA/m (kOe) | Hcj kA/m (kOe) | (BH)max kJ/m³ (MGOe) |
|---|---|---|---|---|
| Y8T | 200-235 (2.0-2.35) | 125-160 (1.57-2.01) | 210-280 (2.64-3.52) | 6.5-9.5 (0.8-1.2) |
| Y10T | 200-235 (2.0-2.35) | 128-160 (1.61-2.01) | 210-280 (2.64-3.52) | 6.4-9.6 (0.8-1.2) |
| Y20 | 320-380 (3.2-3.8) | 135-190 (1.70-2.39) | 140-195 (1.76-2.45) | 18.0-22.0 (2.3-2.8) |
| Y22H | 310-360 (3.1-3.6) | 220-250 (2.76-3.14) | 280-320 (3.52-4.02) | 20.0-24.0 (2.5-3.0) |
| Y23 | 320-370 (3.2-3.7) | 170-190 (2.14-2.39) | 190-230 (2.39-2.89) | 20.0-25.5 (2.5-3.2) |
| Y25 | 360-400 (3.6-4.0) | 135-170 (1.70-2.14) | 140-200 (1.76-2.51) | 22.5-28.0 (2.8-3.5) |
| Y26H | 360-390 (3.6-3.9) | 220-250 (2.76-3.14) | 225-255 (2.83-3.20) | 23.0-28.0 (2.9-3.5) |
| Y26H-1 | 360-390 (3.6-3.9) | 200-250 (2.51-3.14) | 225-255 (2.83-3.20) | 23.0-28.0 (2.9-3.5) |
| Y26H-2 | 360-380 (3.6-3.8) | 263-288 (3.30-3.62) | 318-350 (4.00-4.40) | 24.0-28.0 (3.0-3.5) |
| Y27H | 370-400 (3.7-4.0) | 205-250 (2.58-3.14) | 210-255 (2.64-3.20) | 25.0-29.0 (3.1-3.6) |
| Y28 | 370-400 (3.7-4.0) | 175-210 (2.20-2.64) | 180-220 (2.26-2.76) | 26.0-30.0 (3.3-3.8) |
| Y28H-1 | 380-400 (3.8-4.0) | 240-260 (3.02-3.27) | 250-280 (3.14-3.52) | 27.0-30.0 (3.4-3.8) |
| Y28H-2 | 360-380 (3.6-3.8) | 271-295 (3.41-3.71) | 382-405 (4.80-5.09) | 26.0-30.0 (3.3-3.8) |
| Y30 | 370-400 (3.7-4.0) | 175-210 (2.20-2.64) | 180-220 (2.26-2.76) | 26.0-30.0 (3.3-3.8) |
| Y30BH | 380-390 (3.8-3.9) | 223-235 (2.80-2.95) | 231-245 (2.90-3.08) | 27.0-30.0 (3.4-3.8) |
| Y30H-1 | 380-400 (3.8-4.0) | 230-275 (2.89-3.46) | 235-290 (2.95-3.64) | 27.0-32.0 (3.4-4.0) |
| Y30H-2 | 395-415 (3.95-4.15) | 275-300 (3.46-3.77) | 310-335 (3.90-4.21) | 27.0-32.5 (3.4-4.1) |
| Y32 | 400-420 (4.0-4.2) | 160-190 (2.01-2.39) | 165-195 (2.07-2.45) | 30.0-33.5 (3.8-4.2) |
| Y32H-1 | 400-420 (4.0-4.2) | 190-230 (2.39-2.89) | 230-250 (2.89-3.14) | 31.5-35.0 (4.0-4.4) |
| Y40 | 440-460 (4.4-4.6) | 290-330 (3.64-4.15) | 280-330 (3.52-4.15) | ~38-42 (~4.8-5.3) |
Pressed without field alignment. Lower magnetic performance but allows magnetization in different directions and supports very cost-sensitive applications.
Powder is oriented during pressing, increasing magnetic performance while fixing the preferred magnetization direction.
For motors and speakers, anisotropic grades are typical. Isotropic grades remain useful where cost and flexible magnetization patterns dominate.
Ferrite is a ceramic oxide and normally does not require a corrosion coating.
| Characteristic | Symbol / Unit | Reference Value |
|---|---|---|
| Density | g/cc | 4.9–5.1 |
| Vickers hardness | Hv | 400–700 |
| Compression strength | N/mm² | 680–720 |
| Specific heat capacity | J/kg·°C | 795–855 |
| Electrical resistivity | μΩ·cm | ~1 × 10¹⁰ |
| Curie temperature | °C | ~450 |
| Rev. temp. coeff. Br | %/°C | ~−0.2 |
| Rev. temp. coeff. Hci | %/°C | ~+0.27 |
Motor / speaker rings; ID/OD and faces can be ground.
Dedicated arc-ferrite production for motors.
Industrial holding and separator structures.
Sensors, consumer and holding applications.
Ferrite is hard and brittle; precision features are produced by grinding rather than conventional machining.
As-sintered dimensions are economical; critical ground dimensions can reach around ±0.05 mm, with tighter lapped features project-dependent.
Approx. 100 employees. Main focus: ferrite rings, cylinders/discs and blocks.
Approx. 80+ employees. Main focus: ferrite arc / segment magnets.
Diamond grinding for critical dimensions; magnetic and dimensional inspection to the agreed sampling/control plan.
Workshop, press, kiln, grinding and inspection photos are reserved as real-photo slots for later replacement.
CoA / magnetic-property results can include Br, Hcb, Hcj and (BH)max according to the agreed inspection plan.
Gauge, optical inspection or CMM/3D optical measurement can be used according to geometry and critical dimensions.
Before shipment, we can provide a real-time inspection video showing the product, equipment, measurement process and actual displayed data for remote customer verification.
FAI / PPAP / RoHS / REACH / traceability documents are available according to project and customer requirements.
All technical PDFs in this library are hosted locally on empiremagnets.com and use the current Ningbo Empire document identity and revision format.
Ferrite is a strong choice when magnet volume is available, cost is a major driver, intrinsic corrosion resistance is useful and very high energy density is not required.
Ferrite is a hard ceramic. Functional dimensions are normally created by diamond grinding rather than drilling, tapping or conventional milling.
Arc geometry follows the rotor/stator air gap and ferrite delivers economical magnetic volume for high-volume DC and appliance motor designs.
Yes. The orientation route is selected according to performance target, magnetization pattern and cost.
