What Is the Difference Between Axial and Radial Ring Magnets?

2026-09-18

1. What Is the Physical Difference Between Axial and Radial Magnetization?

The magnetization direction refers to the orientation of the magnetic poles relative to the geometry of the ring. In an axial Ring Magnet, the poles are on the flat faces of the ring. If you place the ring on a table, the top face is one pole (north or south), and the bottom face is the opposite pole. The magnetic field lines run vertically through the thickness of the ring. In a radial Ring Magnet, the poles are on the inner and outer curved surfaces. The magnetic field lines run horizontally from the inner diameter to the outer diameter (or vice versa).

The table below summarizes the geometric difference.

Property	Axial Ring Magnet	Radial Ring Magnet
Pole location	Flat top and bottom faces	Inner and outer curved surfaces
Field direction	Parallel to the axis of the ring	Perpendicular to the axis (radial)
Typical assembly	Magnet sits flat on a surface	Magnet is pressed onto a shaft or into a housing
Number of poles	Usually 2 (one north, one south)	Usually 2, but can be multi-pole
Common material	Neodymium, ferrite, SmCo	Neodymium, ferrite, bonded NdFeB

Xiamen Zhaobao Magnet Co., Ltd. manufactures both axial and radial Ring Magnet units in a range of materials and sizes. Our factory uses precision machining and magnetizing fixtures to ensure that the magnetization direction is accurate to within 2 degrees of the specified orientation.

2. How Does the Magnetic Field Distribution Differ Between the Two Types?

The magnetic field distribution determines how the magnet interacts with the surrounding components. In an axial Ring Magnet, the field is concentrated at the center of the flat faces and spreads outward as it leaves the magnet. The field is strongest near the poles and weakens rapidly with distance. In a radial Ring Magnet, the field is concentrated on the outer surface and extends outward in a pattern that is more uniform around the circumference. This makes the radial configuration better suited for applications where the magnet must interact with a cylindrical component, such as a stator or a shaft. The table below compares the field characteristics of the two configurations.

Field characteristic	Axial Ring Magnet	Radial Ring Magnet
Peak surface field (N42, 20mm OD x 10mm ID x 5mm)	3,200 Gauss	2,800 Gauss
Field uniformity around circumference	Moderate	High
Field extension distance	Short (drops quickly)	Longer (extends radially)
Best for interaction with	Flat sensors, axial coils	Cylindrical stators, shafts

The peak surface field is typically higher for an axial magnet of the same dimensions because the pole area is larger. However, the radial magnet provides a more uniform field around the circumference, which is important for motor applications where cogging torque must be minimized. In our factory, we measure the surface field at multiple points on every Ring Magnet to verify the uniformity.

3. What Are the Typical Applications for Each Type?

The choice between axial and radial magnetization is determined by the application. Axial Ring Magnets are used in applications where the magnet is mounted flat against a surface. Examples include magnetic couplings, magnetic bearings, and some types of sensors. Radial Ring Magnets are used in applications where the magnet is mounted on a shaft or inside a cylindrical housing. Examples include brushless DC motors, stepper motors, and magnetic encoders. The table below lists the typical applications and the recommended magnetization direction.

Application	Recommended magnetization	Reason
Brushless DC motor (outer rotor)	Radial	Field must interact with stator coils around the circumference
Brushless DC motor (inner rotor)	Radial	Field must interact with stator coils on the shaft
Magnetic coupling	Axial	Magnets face each other across a gap
Magnetic encoder	Radial or axial	Depends on sensor orientation
Loudspeaker	Radial	Field must interact with voice coil in the gap
Magnetic bearing	Axial	Magnets repel or attract along the axis

Xiamen Zhaobao Magnet Co., Ltd. supplies Ring Magnet units to motor manufacturers, sensor companies, and research institutions. Our factory can produce both axial and radial magnets in neodymium, ferrite, and samarium cobalt. We also offer custom magnetization patterns, including multi-pole radial magnetization for high-resolution encoders.

4. What Should You Consider When Specifying a Ring Magnet?

When specifying a Ring Magnet, there are five parameters that must be defined. The first is the material grade. Neodymium provides the highest field strength, but it is more expensive and has a lower maximum operating temperature than samarium cobalt. Ferrite is the lowest cost option, but it provides the lowest field strength. The second is the dimensions: outer diameter, inner diameter, and thickness. The third is the magnetization direction: axial or radial. The fourth is the tolerance on the dimensions and the magnetization angle. The fifth is the coating. Neodymium magnets require a protective coating (nickel, zinc, or epoxy) to prevent corrosion. The table below summarizes the key specifications for our standard Ring Magnet products.

Specification	Standard range	Customization available
Material	Neodymium (N35 – N52), Ferrite (Y30 – Y35), SmCo (SmCo24 – SmCo28)	Yes
Outer diameter	5 mm – 200 mm	Yes
Inner diameter	2 mm – 180 mm	Yes
Thickness	1 mm – 50 mm	Yes
Magnetization direction	Axial or radial	Yes (multi-pole available)
Magnetization angle tolerance	±2 degrees	Yes (±1 degree for precision)
Coating	NiCuNi, Zn, Epoxy, Parylene	Yes

Design tip: If you are unsure which magnetization direction is best for your application, consider the assembly method. If the magnet will be pressed onto a shaft, radial magnetization is usually the correct choice. If the magnet will be glued flat to a surface, axial magnetization is usually the correct choice. Our engineering team can review your design and provide a recommendation.

Frequently Asked Questions About Axial and Radial Ring Magnets

Question 1: Can a ring magnet be magnetized in both axial and radial directions simultaneously?

Answer: No, a Ring Magnet cannot be magnetized in both axial and radial directions simultaneously in a standard configuration. The magnetization direction is determined by the orientation of the magnetizing fixture and the material's magnetic anisotropy. However, it is possible to create a multi-pole magnet with alternating axial and radial poles in a single ring. This is done by using a specialized magnetizing fixture with multiple coils. These multi-pole magnets are used in some high-resolution encoders and special motor designs. In our factory, we can produce multi-pole magnets with up to 24 poles, but the magnetization direction is typically uniform (all radial or all axial) with alternating polarity.

Question 2: Which magnetization direction provides a stronger magnetic field?

Answer: For the same dimensions and material grade, an axial Ring Magnet typically provides a slightly higher peak surface field than a radial Ring Magnet. This is because the pole area on the flat faces is larger than the pole area on the curved surfaces. However, the radial magnet provides a more uniform field around the circumference, which is more important for motor applications. The difference in peak field is typically 10 to 15 percent. If your application requires the highest possible field strength at a specific point, axial magnetization may be better. If your application requires a uniform field around a shaft, radial magnetization is better. In our factory, we can simulate both configurations using finite element analysis to help you choose.

Question 3: How does the inner diameter affect the performance of a radial ring magnet?

Answer: The inner diameter of a radial Ring Magnet affects the field strength and the uniformity. A smaller inner diameter means a thinner wall thickness, which reduces the field strength. A larger inner diameter means a thicker wall, which increases the field strength but also increases the cost. There is an optimal ratio of wall thickness to outer diameter that maximizes the field strength per unit volume. For most motor applications, the wall thickness should be between 15 and 25 percent of the outer diameter. In our factory, we can advise on the optimal dimensions for your specific application. We also offer simulation services to predict the performance before manufacturing.

Summary for Motor Design Engineers

The difference between axial and radial Ring Magnet is the direction of the magnetic field relative to the ring geometry. Axial magnets have poles on the flat faces and are used in flat mounting applications. Radial magnets have poles on the curved surfaces and are used in shaft-mounted applications. The choice depends on the application, the assembly method, and the required field distribution. Xiamen Zhaobao Magnet Co., Ltd. has been manufacturing Ring Magnet units for over 15 years and supplies to customers in more than 30 countries.

Xiamen Zhaobao Magnet Co., Ltd. manufactures axial and radial Ring Magnet units in neodymium, ferrite, and samarium cobalt. We provide full magnetic simulation and custom magnetization services.

Need help selecting the right ring magnet for your design? Contact Xiamen Zhaobao Magnet Co., Ltd. for a free consultation. We will review your application and recommend the optimal magnetization direction and material.

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