NdFeB ring and tube magnets are used in loudspeakers, rotary encoders, sensors, holding fixtures and filter applications. Rings are available as axially magnetized cylinders with central holes, or as radially magnetized multipole rings for encoder feedback.
We manufacture rings from small ID 1.5 mm components up to 150 mm outer diameter. Radial multi-pole magnetization (up to 24 poles) is produced with precise pole transitions for sensor and encoder applications.
Key Specifications
| Specification | Value |
|---|---|
| Grades | N30–N48 typical for rings |
| OD range | 3 mm – 150 mm |
| ID range | From 1.5 mm |
| Magnetization | Axial, radial, multi-pole up to 24 poles |
| Tolerance | ±0.05 mm on OD/ID, ±0.1 mm on length |
| Coatings | Ni, Zn, epoxy |
All magnets are produced to order. Please provide grade, dimension (or drawing), magnetization direction, coating and quantity for quotation. Email sales@polemagnet.com or use the inquiry form — we reply within 24 hours.
FAQ
NdFeB Ring & Tube Magnets — FAQ
Can you make radial multipole rings for encoders?
Yes, we produce radially magnetized rings with 2–24 poles. Pole accuracy and transition width are controlled and can be verified with a Gauss probe at the pole surface.
What tolerance can you hold on thin-walled rings?
For thin wall rings we recommend ±0.05 mm on OD and ID. Wall thickness below 1 mm is possible but limited by the sintering process; please consult our engineers with your drawing.
Do you provide free samples for testing?
Yes, sample orders are welcome. Send your drawing or specification together with the intended application so our engineers can recommend the correct grade, magnetization direction and coating before we prepare samples.
Can the factory produce to my drawing with special tolerances?
Yes. We machine, grind and inspect to customer drawing tolerances. For sintered NdFeB the standard machining tolerance is ±0.05 mm and can be tightened to ±0.02 mm with diamond grinding where the geometry allows.
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Need Custom Magnets for Your Project?
Send your drawing, grade, magnetization direction and quantity. Our engineers will reply with a quotation within 24 hours.