01 · Overview
About Ring Magnets
An axially magnetized ring has opposite poles on its flat faces. A diametrically magnetized ring has a pole pair across its diameter. The easy-axis orientation is established during manufacture; the finished field depends on the magnetization and surrounding magnetic circuit.
02 · Drawing review
Drawing review and documented scope
- OD, ID and axial length reviewed together
- Axial or diametric orientation and magnetization specified on the drawing
- Grade, coating and finished tolerances confirmed per part
03 · Typical Use Cases
Where Ring magnets go to work
Voice coil motors (VCM)
Loudspeaker drivers
Magnetic couplings (torque transmission through non-contact interface)
Holding magnets and fixtures
Hall-effect sensor pair magnets
Small electric motor assemblies
04 · Dimensions & Tolerances
Drawing dimensions and tolerances
| Parameter | Specification |
|---|---|
| Typical dimensions | OD, ID and axial length specified on the drawing |
| Tolerances | Dimensions, concentricity and perpendicularity agreed per feature |
Tighter spec?
Send your drawing with the critical surfaces called out. We will confirm the dimensions, production route and inspection requirements for your part.
05 · Grade references
Grade references for Ring
N38
80°C classN38 reference: 36–39 MGOe at 20°C, with a nominal 80°C temperature class.
Reference; drawing review required
N42
80°C classN42 reference: 40–43 MGOe at 20°C, with a nominal 80°C temperature class.
Reference; drawing review required
N45
80°C classN45 reference: 43–46 MGOe at 20°C, with a nominal 80°C temperature class.
Reference; drawing review required
N42H
120°C classN42H reference: 40–43 MGOe at 20°C, with a nominal 120°C temperature class.
Reference; drawing review required
N45H
120°C classN45H reference: 43–46 MGOe at 20°C, with a nominal 120°C temperature class.
Reference; drawing review required
06 · Related Applications
Related Applications
Industrial Automation
NdFeB magnets for stepper motors, servo drives, linear actuators, magnetic couplings, and factory automation equipment across European and North American manufacturing.
Medical Devices
NdFeB design considerations for medical equipment mechanisms, sensors and permanent-magnet MRI systems.
Frequently Asked Questions
What is the difference between axial and diametric magnetization on a ring magnet?
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Axial magnetization places opposite poles on the flat faces. Diametric magnetization places the pole pair across the diameter. Select the orientation during part design and assess the resulting field in the assembled circuit.
What is the smallest ring magnet you can produce?
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Minimum dimensions depend on wall thickness, axial length, grade and process route. Send the complete drawing for a size and tolerance review; the radial multipole ring window is a separate construction.
Next step
Request a Quote for Ring Magnets
Share dimensions, quantity, grade target and operating conditions. We respond within 1 business day. The production route and acceptance requirements are confirmed during drawing review.