A true radial magnet is typically a ring magnet whose magnetization direction points radially inward or outward around the full circumference. In a simple two-pole radial ring, magnetic flux is directed between the inner and outer circumferences rather than through the flat faces.
Ring shape and radial magnetization are not the same thing. Most conventional stock ring magnets are axially magnetized, with north and south poles on the two flat faces. If you need standard neodymium or ferrite rings by outer diameter, inner diameter and thickness, browse our Ring Magnets. If your drawing specifically calls for radial, diametric or multipole magnetization, continue below or submit it through the Magnet RFQ Builder.
Ring Magnet Shape vs. Magnetization Direction
| Ring type | Where the poles are | Typical sourcing path |
|---|---|---|
| Axially magnetized ring | Opposite flat faces | Common stock configuration; browse Ring Magnets |
| Diametrically magnetized ring | Opposite sides across one diameter | Often custom; common in rotary sensing and encoders |
| True radial ring | Inner vs. outer circumference in a simple two-pole design | Specialized and commonly custom |
| Multipole ring | Alternating poles around a face or circumference | Usually application-specific/custom |
How True Radial Magnetization Works
In a true radial ring, the local direction of magnetization changes continuously as you move around the circumference. Each point is magnetized along a radius of the ring rather than along one fixed global axis.
For a basic two-pole design, magnetic flux is directed between the inner diameter and outer diameter. More complex radial multipole patterns can also be engineered when the application requires multiple alternating poles around the ring.
True Radial vs. Diametric Magnetization
| Feature | True Radial Ring | Diametrically Magnetized Ring |
|---|---|---|
| Magnetization direction | Changes continuously around the circumference along radial directions | One straight direction across the diameter |
| Pole arrangement | Inner/outer circumference for a simple two-pole radial ring | Opposite sides of the curved surface |
| Typical use | Motor rotors, generators, couplings, bearings | Rotary sensors, encoders, shaft-position sensing |
| Manufacturing | Specialized and commonly custom | More conventional custom magnetization |
For a full comparison, see Diametrically Magnetized vs. Radially Magnetized Magnets. For sensor-specific selection, see How Sensor Magnets Work.
True Radial vs. Standard Axial Ring Magnets
A conventional axial ring is magnetized through its thickness, so one flat annular face is north and the opposite flat face is south. The center hole changes the geometry of the magnetic circuit, but it does not make the magnet radially magnetized.
This distinction is important on drawings and RFQs. If the requirement is simply a ring-shaped magnet with a bore for a shaft, fastener, clearance feature or assembly, an axial stock ring may be appropriate. Search the Ring Magnets catalog by OD, ID, thickness, grade and pull-force range before specifying a custom magnetization pattern.
True Radial vs. Segmented Arc Magnets
A rotor assembled from arc segments can be designed to approximate a radial magnetic field, but a segmented assembly is not automatically a true radial ring. Individual arc segments are often magnetized along straight directions, while a one-piece true radial ring has a continuously changing local magnetization direction.
Segmented designs can still be excellent engineering solutions. The choice between a one-piece radial ring and a segmented rotor depends on pole count, torque, air gap, magnet material, assembly method, cost and available manufacturing processes.
Where Are True Radial Magnets Used?
- Permanent-magnet motors: radial rings can create the field geometry required around a rotor or stator air gap.
- Generators: specialized radial magnetization can support compact rotary magnetic circuits.
- Magnetic couplings: annular field patterns can transfer torque without direct mechanical contact.
- Magnetic bearings: radial field geometry may be used in specialized non-contact bearing systems, often with another stabilizing or constraining element because passive permanent magnets alone cannot provide stable equilibrium in every axis.
- Custom rotary assemblies: where a one-piece ring simplifies assembly or improves field consistency.
For permanent-magnet bearing architectures, stabilization methods, working-gap effects and Halbach-array approaches, see the Magnets for Magnetic Levitation & Bearings Design Guide. For general motor-magnet principles, read How Magnets Work in Electric Motors.
What Materials Can Be Used?
True radial magnetization can be produced in suitable permanent-magnet materials, but the practical material choice depends on geometry, field requirement, operating temperature, corrosion exposure and manufacturing method. Neodymium is often attractive where high energy density is required, while ferrite, SmCo or other materials may be appropriate in different magnetic circuits.
Use our Magnet Material Comparison to compare NdFeB, SmCo, ferrite and Alnico, and the Neodymium Magnet Grade & Property Chart when selecting an NdFeB grade.
Why True Radial Magnets Are Usually Custom
True radial rings generally require specialized magnetizing fixtures, tooling and process control. Geometry, pole count, grade, magnetic orientation and dimensional tolerances all affect manufacturability. For that reason, they are much more commonly specified as engineered custom parts than as general-purpose stock magnets.
When requesting a quote, provide the ring OD, ID and thickness; material and grade; coating; magnetization direction and pole count; operating temperature; dimensional tolerances; target field or torque requirement; annual quantity; and any inspection or PPAP requirements.
Need a Stock Ring or a True Radial Ring?
For conventional axial rings, start with the Ring Magnets catalog. For a true radial, diametric or multipole ring, use the Magnet RFQ Builder to submit your drawing and magnetic requirements. Production programs can also review our Quality & Compliance capabilities for inspection, traceability and PPAP support.
