EV & Automotive Magnets

Radial Magnets supports automotive OEM, Tier 1 and Tier 2 programs with stocked and custom permanent magnets for traction motors, BLDC/PMSM rotors, Hall/TMR sensors, actuators, pumps and retention systems. Procurement and engineering teams can source production quantities with dimensional and magnetic inspection, traceability, compliance documentation and PPAP support.

Start with the requirement you already have: Search stocked magnets, submit a drawing through the Magnet RFQ Builder, or send several part numbers and annual volumes through the Bulk Magnet RFQ.

Traction-Motor and BLDC/PMSM Rotor Magnets

Permanent-magnet automotive motors may use surface-mounted arc segments or blocks, interior permanent magnets, multipole rings, radially magnetized rings or other rotor-specific geometries. The correct magnet is selected around the air-gap field, torque target, rotor architecture, continuous and fault temperature, opposing stator field, mechanical retention and demagnetization margin—not simply the highest N-grade.

For the engineering side of rotor selection, see Magnets for Electric Motors: Rotor Design & Selection Guide and How Magnets Work in Electric Motors.

Common Automotive Magnet Applications

• EV traction-motor rotor assemblies
• BLDC and PMSM motors for HVAC, pumps and actuators
• Wheel-speed and ABS sensors
• Electric power-steering position sensors
• Transmission and shaft-speed sensing
• Throttle-position and pedal sensors
• Door, seat, latch and closure systems
• Thermal-management pumps and compact auxiliary motors
• Rotary encoders and motor-position feedback

High-Coercivity Neodymium Grades for Automotive Duty

Under-hood, transmission and motor environments can expose magnets to elevated temperature and opposing magnetic fields. In those conditions, intrinsic coercivity (HcJ) and the magnet’s operating point can matter more than room-temperature surface field alone.

Standard and higher-coercivity NdFeB families such as M, H, SH, UH, EH and AH may be evaluated depending on the actual geometry and duty cycle. A published maximum operating temperature should not be treated as a universal safe limit for every rotor or sensor geometry.

Compare Br, HcJ, BHmax and published temperature limits in the Neodymium Magnet Grade Chart. For preliminary engineering screening, use the Temperature Derating Calculator and Demagnetization & Permeance Coefficient Calculator.

Rotor Geometry, Magnetization and Mechanical Retention

Automotive motor magnets should be specified as part of the complete rotor system. Important drawing requirements can include:

• Arc, block, segment or ring geometry and dimensional tolerances
• SPM or IPM rotor architecture
• Axial, radial, diametric or multipole magnetization
• Pole count, indexing and pole-to-pole consistency
• Rotor air gap and tolerance stack
• Adhesive bond-line or sleeve allowance
• High-speed centrifugal retention requirements
• Coating and corrosion-protection system
• Magnetic inspection location and acceptance range

For unusual field patterns or one-sided air-gap concentration, review Halbach Arrays Explained. For field verification at a defined working distance, use the Magnet Field Distance Calculator.

Automotive Sensor Magnets

Hall-effect, TMR, AMR and other magnetic sensors are used throughout automotive systems for position, speed, angle and proximity feedback. For these parts, the critical requirement is usually magnetic field magnitude and direction at the sensor location across the full air-gap and tolerance range, not catalog pull force.

See Sensor Magnets for Hall, TMR, AMR & Rotary Position Sensing and browse stocked Sensor Magnets for prototype and production options.

PPAP & Supplier Qualification Support

Automotive programs may require PPAP submissions, dimensional reports, magnetic-performance data, material declarations, lot traceability and formal change control. Radial Magnets can support PPAP Levels 1–5 and customer-specific qualification requirements where defined by the program.

• Certificate of Conformance and material certification
• Dimensional inspection and magnetic inspection records
• Lot traceability and production identification
• RoHS, REACH, PFAS and other requested material-compliance documentation
• Customer-specific PPAP documentation and approval packages
• Packaging, labeling and change-control requirements

Review our Quality & Compliance capabilities and Compliance Document Center during supplier qualification.

What to Include on an Automotive Magnet RFQ

• Drawing and part number
• Magnet material, grade and coercivity class
• Dimensions and tolerances
• Magnetization direction, pole count and indexing
• Continuous, peak and fault temperature
• Required field, force or torque at the working condition
• Coating or environmental requirement
• Magnetic and dimensional inspection criteria
• Prototype quantity and annual production volume
• PPAP level, traceability and compliance-document requirements

Source an Automotive Magnet Program

Prototype or existing size: Search Inventory. Custom drawing or new design: Build an RFQ. Multiple parts, annual quantities or BOM: Submit a Bulk RFQ. PPAP or regulatory paperwork: Review Compliance Documents.