When To Use Multi‑pole Ring Magnet Instead of Arc Segment Magnet for BLDC Motor

When designing BLDC brushless motors, engineers often choose between multi‑pole hollow ring magnets and segmented arc‑segment magnets. Understanding their differences helps you pick the right magnet for your project.

Multi‑pole radial ring neodymium magnet is one‑piece hollow cylindrical magnet with alternating N‑S poles around its circumference. It removes assembly gaps caused by gluing multiple arc tiles together, delivering smoother magnetic flux, lower cogging torque and quieter motor operation. It is widely adopted for micro‑precision BLDC, hollow‑cup motors, robot joints and small servo motors, where stable low‑speed performance matters most. Bonded neodymium multi‑pole rings are popular for compact small‑size motors.

However,  multi‑pole ring magnets haves high mold and manufacturing costs, especially for large dimensions. For medium‑to‑high‑power BLDC motors, EV drive motors and fans, arc‑segment  magnets remain the dominant solution. Arc‑segment magnets provide flexible grade options including M, SH, UH high‑temperature grades at competitive costs.

As a professional neodymium magnet manufacturer, we supply both multi‑pole ring magnets and arc‑segment magnets. Share your motor parameters, and we can offer free technical review and competitive quotation for your BLDC motor projects.