Injection Molded NdFeB Magnets
Contact Us Now
Injection molded NdFeB magnets combine neodymium magnetic powder with PA6, PA12, PPS or another engineering thermoplastic. The compound is injected into a precision mold to produce complex magnetic geometries, thin-wall rings, gears and components with integrated shafts, hubs or carriers.
The process provides excellent shape freedom, mechanical toughness, electrical resistivity and high-volume repeatability. Vanguard supports BNI material selection, mold and insert design, multi-pole magnetization, prototype validation and magnetic subassembly production.
Request Engineering Review
Magnetic output, operating temperature, moisture exposure and mechanical load determine powder loading and whether PA6, PA12 or PPS is appropriate.
Gate location, flow path, weld lines, shrinkage, draft and demolding direction affect dimensions, strength and magnetic uniformity.
Shaft and hub geometry should provide reliable mechanical interlock while controlling runout, flash and stress around the insert.
Pole count, phase angle, pole pitch, reference mark and waveform acceptance criteria must be established before fixture release.
The following table retains the six BNI grades and values used on the original website page. Final performance depends on powder type, resin system, powder loading, molding conditions, part geometry and magnetization fixture.
| Grade | Remanence Br | Coercivity Hcb | Intrinsic Coercivity Hcj | Max. Energy Product | Max. Working Temp. | Typical Binder | ||||
|---|---|---|---|---|---|---|---|---|---|---|
| mT | kG | kA/m | kOe | kA/m | kOe | kJ/m³ | MGOe | |||
| BNI-2 | 250–330 | 2.5–3.3 | 160–240 | 2.0–3.0 | 400–600 | 5.0–7.5 | 12–20 | 1.5–2.5 | 120–150 °C | PA / PPS |
| BNI-3 | 330–420 | 3.3–4.2 | 200–280 | 2.5–3.5 | 440–640 | 5.5–8.0 | 20–28 | 2.5–3.5 | 120–150 °C | PA / PPS |
| BNI-4 | 420–500 | 4.2–5.0 | 240–320 | 3.0–4.0 | 480–680 | 6.0–8.5 | 28–36 | 3.5–4.5 | 120–150 °C | PA / PPS |
| BNI-5 | 500–580 | 5.0–5.8 | 280–360 | 3.5–4.5 | 520–720 | 6.5–9.0 | 36–44 | 4.5–5.5 | 120–150 °C | PA / PPS |
| BNI-6 | 560–640 | 5.6–6.4 | 320–400 | 4.0–5.0 | 560–760 | 7.0–9.5 | 44–52 | 5.5–6.5 | 120–150 °C | PA / PPS |
| BNI-7 | 620–700 | 6.2–7.0 | 360–440 | 4.5–5.5 | 600–800 | 7.5–10.0 | 52–60 | 6.5–7.5 | 120–150 °C | PA / PPS |
| Parameter | Unit | Typical Value |
|---|---|---|
| Density | g/cm3 | 4.5–5.6 depending on powder loading |
| Binder System | – | PA6 / PA12 / PPS / custom engineering plastic |
| Electrical Resistivity | Ω·cm | High, suitable for low eddy-current loss |
| Working Temperature | °C | Typically 120–150 °C, resin dependent |
| Corrosion Resistance | – | Good due to polymer binder; coating available for harsh environments |
| Process Advantage | – | Complex shape, insert molding and high-volume repeatability |
Injection molding supports complex profiles, thin-wall rings, integrated gears, shaft inserts, plastic carriers and parts with locating features. Mold design must consider flow, shrinkage, insert retention and magnetization-fixture access.
| Item | Capability | Notes |
|---|---|---|
| Outer Diameter / Length | 2–150 mm typical | Larger sizes reviewed by mold and injection capacity |
| Wall Thickness | Thin-wall and complex parts available | Confirmed by flow, strength and powder loading |
| Standard Tolerance | ±0.05 mm to ±0.15 mm | Depends on resin, size, mold and critical dimensions |
| Integrated Features | Gear, hub, shaft insert, slot, keyway, marker, carrier | Designed for assembly and magnetization inspection |
Integrated magnetic rotors for compact BLDC motors, coolant pumps, fan motors and fluid-handling systems.
Multi-pole rings and wheels for angle, speed and position measurement with controlled waveform output.
HVAC actuators, valve drives and auxiliary mechanisms requiring complex geometry and repeatable volume production.
Small motors, gears, office equipment and smart mechanisms benefiting from insert molding and fewer assembly steps.
Powder loading, pellet conditioning, melt flow, mold temperature, injection pressure and shrinkage are controlled by batch.
Surface flux, pole count, pole angle, phase position, magnetic waveform and batch consistency can be verified.
OD, ID, thickness, runout, insert position, gear profile, flatness and functional interfaces are checked to drawing.
Material, dimensional and magnetic reports, RoHS/REACH documents and PPAP-style records are available on request.
Injection molding uses a thermoplastic binder and provides greater shape freedom, insert molding and high-volume integration. Compression molding generally reaches higher magnetic output but offers less complex geometry.
PA12 offers low moisture absorption and dimensional stability, PA6 can provide strength and process economy, while PPS is considered for higher temperature and chemical resistance. Final selection depends on the complete operating environment.
Yes. Multi-pole rings are widely used in encoders, sensors and small motor rotors. Pole count, phase and waveform should be defined before fixture development.
Yes. Insert and functional integration are major advantages, subject to flow, retention, runout, shrinkage and tooling feasibility.
Please provide a drawing or 3D model, target magnetic output, resin or temperature requirement, dimensions and tolerances, insert details, pole pattern, sample quantity and annual volume.
Send the drawing, magnetic target, binder or temperature requirement, insert details and pole pattern. Our team can review material, mold, magnetization and inspection requirements before quotation.
Contact Us
