Neodymium Magnets for Robotics

It depends on the robot. Drones and sensor feedback magnets typically use high-Br N52M; AGV/AMR wheel-hub motors use N48H; industrial robotic arms use N45SH; humanoid and cobot joint actuators use GBD N45UH–N48UH for high coercivity at continuous temperature; and surgical-robot tools running hot use N42EH. Operating temperature and duty cycle — not just torque — drive the choice. Mainrich engineers will match the grade to your specific actuator before tooling.

Yes — provided the grade is selected for the joint's steady-state temperature with margin above the knee point, not just its peak torque. The failure mode in continuous-duty joints is thermal heat-soak, not transient load. Mainrich specifies GBD N45UH or N48UH (knee point ~150°C) for cobot joints, and validates flux loss below the design threshold across the duty cycle. Cobot fleets running on these grades have reported zero demagnetization failures over two years of continuous supply.

It is grade-dependent: N52M up to ~100°C, N45SH to 150°C, N45UH / N48UH to 180°C, and N42EH to 200°C. The number that actually governs your design is the knee-point temperature — the point on the demagnetization curve where irreversible loss begins — not the nominal Tmax. We size every robotics magnet so the knee point sits comfortably above the joint's worst-case continuous temperature. Demagnetization curves at operating temperature are available per grade on request.

For high-speed BLDC motors (drones) and high-frequency PMSM joint drives, yes — inverter switching induces eddy currents in the magnet body, generating heat and loss. Block-laminated segmentation with epoxy insulation layers ≤ 30 μm (typically 4–12 slices per pole) cuts rotor magnet losses by 40–70% and reduces rotor heating. For low-speed, low-frequency joints, monolithic arc magnets are perfectly adequate. Send us your operating frequency and rotor geometry and we'll advise.

Mainrich operates under MIIT-licensed supply agreements for Dy and Tb and has been export-license-ready since the 2025 rare-earth control framework came into force. For every order we prepare country-of-origin certificates, conflict-mineral declarations, and export license documentation within 5 business days. Our Grain Boundary Diffusion process also materially reduces heavy rare-earth intensity in SH / UH / EH grades, lowering exposure to future control shocks. For programs sensitive to supply risk, we can stage safety stock against a signed 12-month forecast.

Minimum order quantity starts at 10 pieces per specification — suitable for prototype and engineering-validation phases. Sample lead time is 10–15 business days; mass production is 30–45 business days depending on grade and volume. We recommend ordering samples first to validate dimensions, magnetization, and thermal behavior before committing to full production tooling. Monthly capacity for robotics grades exceeds 5 million pieces.

Yes. Surgical and medical-robot magnets typically require biocompatible coatings — Parylene C or medical-grade epoxy — that withstand sterilization cycles (autoclave, EtO, or gamma) and meet biocompatibility requirements where there is patient-contact risk. Mainrich supplies these coatings together with full material traceability and ISO 13485-aligned documentation for the medical-device supply chain. Specify your sterilization method and contact classification and we'll recommend the coating system. For EU-market chemical compliance, refer to ECHA REACH guidance.

They differ in coercivity, knee-point temperature, and heavy-rare-earth content. N42SH (Hcj ≥ 1592 kA/m, 150°C) suits moderate-duty joints and AGV motors. N45UH and N48UH (Hcj ≥ 1990 kA/m, 180°C) are the high-demand joint grades for humanoid and cobot actuators, where continuous heat and peak-torque demag fields are highest. Between them, N48UH offers slightly higher Br (≈13.9 vs 13.5 kGs) for more torque density. All three use GBD to keep Dy/Tb — and cost — down.

Yes. Humanoid joint actuators are a flagship application for Mainrich. We supply segmented GBD N45UH–N48UH arc magnets engineered for the compact, high-torque-density frameless joint modules these platforms use, with low-cogging segmentation for smooth gait and manipulation. We work under NDA to your motor designer's rotor geometry, pole count, and thermal envelope, and ramp from prototype to serial on dedicated high-temp lines. Send your actuator spec for a DFM proposal.

Sensor magnets optimize for field-angle accuracy and stability, not raw force. They are usually diametrically magnetized rings or discs where the magnetization-axis tolerance and dimensional precision determine how accurately a Hall or magnetoresistive sensor reads position or torque. Thermal stability of the field angle matters more than peak energy product. Motor magnets, by contrast, optimize Br for torque and Hcj for demag resistance. Mainrich holds the tight magnetization-axis and dimensional tolerances that encoder and F/T-sensor accuracy depends on.