Ring magnet, also known as donut magnet, annular magnet, magnetic ring, round ring magnet, or toroidal magnet, is a donut-shaped permanent magnet widely used in motors, sensors, couplings, and loudspeakers.
A ring magnet is a donut-shaped permanent magnet with a hole in the center, typically made from neodymium, ferrite, or samarium cobalt. Its unique shape makes it easy to mount on shafts, rods, or screws, and it can be magnetized axially or diametrically. Ring magnets are widely used in electric motors, generators, sensors, loudspeakers, magnetic couplings, and medical devices. They provide strong, stable magnetic fields and are valued for combining high strength with practical assembly options, making them versatile in both industrial and everyday applications.

what is ring magnet

Ring magnet information: Ring magnets are flat, circular, and have a hole in the center. They are widely used and compact, but their magnetic force is slightly weaker than that of disc magnets. Ring magnet is a hot selling magnet in the market. People can buy many different shapes, sizes, and magnetic materials (like neodymium, ferrite, samarium) from the store. As a neodymium magnet factory, we offer ring neodymium magnets of N, H, M, SH grades with different coatings.

What is Small Ring Magnets

Small ring magnets are simply miniature versions of standard ring magnets, designed with a donut-like shape (a circular magnet with a hole in the center), but in smaller dimensions—usually just a few millimeters to a couple of centimeters in outer diameter.

uses of Ring Magnet

Ring magnets, with their unique shape, have various applications due to their strong and focused magnetic field. Here are some common uses:

1. Motors and Generators: Often used in electric motors and generators to create rotational motion.
2. Magnetic Bearings: Help reduce friction in high-speed machinery, used in applications like flywheels and magnetic levitation trains.
3. Magnetic Couplings: Allow for contactless transmission of power in pumps and mixers.
4. Sensor Applications: Used in sensors for position detection and encoders in automotive and industrial equipment.
5. Magnetic Stirring: Common in laboratory equipment like magnetic stirrers.
6. Magnetic Separators: Used to remove ferrous particles from non-ferrous materials in industries such as mining and recycling.
7. Repair and Restoration: Employed in certain types of repairs for precision instruments, tools, or electronics.
8. Speaker Components: In speakers and headphones, ring magnets help produce sound by interacting with the voice coil.
9. Medical Devices: Used in MRI machines and other medical diagnostic equipment.

Osenc can provide a variety of different ring magnets for sale, and we can also customize them according to your needs.

ring magnets magnetic field

Axial Magnetization

In axial magnetization, the north and south poles are located on the two flat circular faces of the ring magnet. The magnetic field lines extend from one face, curve outward, and return to the opposite face, creating a concentrated field along the central axis. This directional strength makes axially magnetized ring magnets especially effective in motors, sensors, and speakers, where a stable and powerful axial magnetic field is required for efficient performance.

Diametrical Magnetization

In diametrical magnetization, the poles are positioned on opposite curved sides of the ring rather than the flat faces. The magnetic field runs across the diameter, producing a sideways or rotational magnetic effect. This type of field distribution is less common than axial magnetization but very useful in specialized applications. Diametrically magnetized ring magnets are often used in rotary encoders, magnetic couplings, and other systems where lateral magnetic detection or contactless torque transfer is required.

Field Strength Distribution

The magnetic field of a ring magnet is not uniform; it is strongest near the inner edge of the hole and along the outer rim. This unique distribution allows the magnet to maintain powerful localized fields while still being easy to mount onto shafts or rods. By adjusting the thickness and diameter of the ring, engineers can focus or spread the magnetic flux, making it adaptable for sensors, couplings, and precision instruments where field control is essential.

Ring Magnets With A Hole

Ring magnets, needless to explain, have a circular shape and a hollow center. About the hollow center, there are 2 shapes in the market:

Normal Hole

A ring shaped magnet is a disc magnet with a concentric hole drilled through the center. The normal hole ring magnet can use for many different applications and their size can be bigger, like OD 250mm and ID 200mm. Most normal hole small ring magnets are used for headphones, and big ring magnets use for speakers and climbing robots (A Comparative Study of Adhesion Mechanism for Wall Climbing Robots: Ring Magnet vs. Block Magnets, Jaise Jose).

Countersunk

A countersunk magnet is a ring magnet with one side appearing as a standard ring; meanwhile, the other side featuring an angled countersink which allows a screw head to fit inside. The angle usually being (but not always) 90 degrees.

Most countersunk magnets have a small hole, because the countersunk will fill in with a screw. And most countersunk neodymium magnets are used for fishing magnets. The biggest fishing magnet can hold almost 1-ton goods.

Powerful Ring Magnets

If you want to buy a powerful ring magnet, there are two options:

• First, you can increase the size of the ring. This will increase its strength, but it will also make it heavier and more cumbersome.
• Second, you can use high-performance materials like neodymium or SmCo. These magnets are lighter and stronger than regular magnets but they cost more money and they are less resistant to corrosion.

If you want to get higher power, like 1.6T (16,000Guass), you should use the Halbach array.

That is not a real ring magnet. It is a magnet assembly. The following Halbach array is what we produced for MPG (Max-Planck–Gesellschaft).

The most popular ring magnet is the neodymium ring. They can bring supreme strength to the application because they are made of rare earth neodymium magnetic material.

Most of the time, neodymium ring magnets are used in applications such as stereo systems, loudspeakers, motors, and sensors used in automotive and other high-tech, high-value applications, and in technology such as generators. Ring magnets are also utilized in new tech developments, such as robotics and hot new consumer electronics.

The advantages of ring magnets?

Ring magnets have several advantages over other types of magnets.

Firstly, their unique shape provides a more uniform magnetic field across their circular surface, making them ideal for applications that require a consistent magnetic field.

Secondly, their compact size and shape make them easy to handle and integrate into various systems. Ring magnets also have a higher magnetic pull force compared to other magnets of similar size, which makes them ideal for applications that require a strong magnetic field.

Additionally, they can be magnetized in various orientations, which adds to their versatility. Finally, ring magnets are widely available in different sizes, shapes, and magnetic strengths, making them suitable for a broad range of applications.

Where to buy ring magnets

1. Local Store

You can search for magnet stores near your company. You can test magnets in the store to see if they are what you need.

2. Amazon

As we know, Amazon has the best service. But sometimes, you can not make sure the grade is now really what you want.

3. Oline Store

• Titan Magnetics
• Buy Magnets
• Magnet Shop
• Super Magnete
• kj Magnetics
• RS-components

4. Manufacturer

If you need some special ring magnets (like high grade, epoxy coating, very big or very small), you should buy it from the magnet manufacturer directly. Like the neodymium magnet, there are five factors, dimension, coating, grade, and magnetized direction.  You are hard to buy N52 neodymium magnet from the stock. Placing an order to the factory is the best solution.

Osenc is neodymium ring magnets factory from China. We supply different types and sizes of neodymium ring magnets for sale. We can custom according to your needs.

Related:

small ring magnets

grades of magnets

FAQ

what are the practical uses for disc, ring, and block magnets?

Magnet Shape	Field Characteristics	Main Uses	Typical Industries
Disc Magnet	Flat, poles on circular faces, broad surface contact	Electronics, sensors, closures, magnetic therapy, toys	Consumer electronics, medical devices, educational tools
Ring Magnet	Hole in the center, can be axially or diametrically magnetized, good for rotation	Motors, generators, speakers, magnetic couplings, sensors	Automotive, renewable energy, audio equipment, industrial machinery
Block Magnet	Large flat surfaces, stable and strong field	Clamping, lifting, magnetic chucks, door catches	Construction, machining, heavy industry, tools