If you’re a manufacturer, engineer, or hobbyist working with ring magnets, chances are you’ve faced the same question I hear in my inbox at least a dozen times a week: How do I make my ring magnets stronger? Over the 12 years I’ve been in the ring magnet supply business, I’ve talked to folks building electric motors, MRI machine components, hard drive actuators, and even DIY art installations that rely on consistent, strong magnetic force. A lot of them come in with a misconception: that the only way to boost strength is to swap in a bigger, more expensive magnet. But that’s rarely the case. Strength in ring magnets is a combination of material, design, and manufacturing choices—and as a supplier who’s worked with clients to tweak every step of the process, I’ve seen how small changes can add up to big results without breaking the bank. Ring Magnets
Let’s start with the basics, because you can’t adjust what you don’t understand. A ring magnet’s strength isn’t just a single number; it’s the magnetic flux density (measured in gauss or tesla) at the magnet’s surface, plus how effectively that flux does work in your application. For example, if you’re using a ring magnet to hold a door closed, your priority is surface flux. If you’re using it in a motor, you need the flux to transfer smoothly between the magnet and the stator or rotor, so the magnetic circuit’s efficiency matters more than raw flux alone. That distinction is key, because the fixes for boosting strength will depend on what you’re actually using the magnet for.
First, the material. This is the foundation. Not all ring magnets are created equal, and swapping for a higher-grade material is often the fastest, most impactful way to get stronger force. Let’s break down common options: Ferrite (ceramic) ring magnets are the most affordable, but their maximum energy product (BHmax, a standard measure of magnetic material strength) is around 3.5 MGOe. Neodymium, the rare-earth magnet most people know, has a BHmax ranging from 28 MGOe up to 50 MGOe for high-grade versions. Samarium-cobalt is another rare-earth option, with BHmax between 16 and 32 MGOe, and it’s more heat-resistant than neodymium—so if your application runs hot, that’s a consideration. I worked with a pump manufacturer two years ago who was using ferrite rings in their impellers; when we swapped them for a 35 MGOe neodymium ring, they saw a 40% increase in holding force without changing the physical size of the magnet. That’s a win for them, because they didn’t have to retool their mold or adjust the pump’s casing. The only caveat here: higher-grade materials are more expensive, so you’ll need to balance cost against your required performance. For some of our long-term clients, we’ll help them phase in higher-grade materials gradually, so they don’t have to absorb a huge price jump all at once.
But material alone isn’t enough. The shape and dimensions of the ring itself make a huge difference. Ring magnets have three key dimensions: outer diameter (OD), inner diameter (ID), and axial thickness (the height of the ring, from one flat face to the other). A common mistake I see is clients assuming a bigger OD will mean a stronger magnet, but that’s not always true. Let’s talk about flux concentration. For a ring magnet, the strongest magnetic field is at the inner edge of the ID, right around the hole. If you have a ring with a large ID and thin wall, most of the material is far from the center, so the flux dissipates before it reaches the area where you’re using it. For example, if you need flux at the center of the ring (say, to attract a shaft passing through), a thicker wall with a smaller ID will concentrate more flux there. We had a robotics client who was using a 50mm OD, 25mm ID, 5mm thick neodymium ring in a gripper; their grip force was too weak, so we adjusted the ID to 15mm and increased the wall thickness to 17.5mm, keeping the OD the same. The grip force jumped by 25% because we moved more of the magnetic material closer to the center where the force was needed.
Axial thickness is another big one. Thicker ring magnets can hold more magnetic material and have a higher volume, which translates to more flux. But it’s not a linear relationship—doubling the thickness doesn’t double the strength, because the inner part of the magnet (the part farthest from the faces) contributes less to the surface flux. Still, for applications where you have space to add axial thickness, it’s a low-cost way to boost strength. A customer who makes magnetic separators for recycling told me they originally used 10mm thick rings; when we switched to 15mm thick rings, their separator’s ability to pull out small ferrous fragments increased by 18%, and they didn’t have to change the ring’s OD or ID to fit their existing equipment. One thing to watch with axial thickness: if you’re using the ring in a rotating application (like a motor), too much thickness can increase inertia, which reduces efficiency. It’s a trade-off, but one we can help you navigate based on your specific use case.
Pole configuration is another design choice that’s often overlooked. Most standard ring magnets are “one pole”—they have a north pole on one flat face and south on the other, or a north pole along the outer edge and south along the inner edge. But multi-pole ring magnets, where you have alternating north and south poles around the ring’s circumference, can be much stronger for applications like motors, sensors, or magnetic couplings. For example, a 4-pole ring magnet will have twice the number of flux transfer points between the magnet and a mating component, so the overall force is higher than a single-pole ring of the same size. I worked with a drone manufacturer last year who was having trouble with their motor’s torque output; switching from a 2-pole to a 8-pole neodymium ring (same OD, ID, and thickness) increased their motor’s torque by 30%, which let them reduce the battery size and extend flight time by 12 minutes. The key here is that multi-pole magnets require more precise magnetization during manufacturing, so as a supplier, we work closely with clients to design the pole count that matches their application—no over-engineering, just the right number of poles to get the strength they need.
Then there’s magnetization process, which is a manufacturing step that can make or break a ring magnet’s strength. If the magnet isn’t fully magnetized during production, it won’t reach its maximum possible flux. Many suppliers use standard magnetization equipment, but we invest in high-strength pulsed magnets that saturate the ring evenly, from the outer edge to the inner hole. We test every batch of ring magnets we ship to confirm their residual flux (Br) and coercivity (Hc), which are the two key magnetic properties that determine strength. A common issue I see with cheaper suppliers is that they under-magnetize to save on power costs, which means their magnets are only 80-90% of their rated strength. When a client switches to our magnets after getting disappointing results elsewhere, the increase in strength is often just from full magnetization, not even a change in material or size. We also offer custom magnetization directions: some applications require radial magnetization (where the poles run along the radius of the ring, not the flat face) or circumferential magnetization, which can boost flux in specific areas. For example, a magnetic coupler using a radially magnetized ring will have a much higher torque capacity than an axially magnetized ring of the same size.
Wait, let’s talk about a common myth I hear all the time: “Can I magnetize a ring magnet further after it’s been manufactured?” The short answer is no. Once a magnet is sintered (for neodymium or ferrite) or bonded, it’s already been magnetized to its maximum capacity during production. Trying to re-magnetize it later won’t increase its strength, and it can even damage the magnet, especially if it’s a brittle rare-earth magnet. That’s why getting the magnetization right during manufacturing is non-negotiable.
Now, what if you’re working with an existing design and can’t change the size or material? There are a few external tweaks you can make to boost the effective strength of your ring magnet. The first is adding a magnetic back iron (also called a flux return) to the magnet. Back iron is a soft magnetic material (usually steel) that sits on the non-working face of the ring, and it guides the magnetic flux back into the circuit instead of letting it dissipate into the air. For example, if you have a ring magnet holding a sign on a wall, adding a steel plate behind the magnet will double or triple the holding force, because the flux that would have escaped into the wall is instead concentrated back through the magnet. We often supply back iron plates alongside ring magnets for our clients, and we’ve seen holding force increase by up to 150% in some cases. Another external tweak is spacing: the closer the ring magnet is to the component it’s attracting, the stronger the force. Even a 1mm gap can reduce force by 20-30%, so making sure the magnet is flush against the mating part (no paint, grease, or debris in between) is a simple fix.
I should also mention degradation, because a lot of clients come to me with a magnet that’s “lost strength” over time, and they assume they need a new one. The main causes of magnetic degradation are heat, corrosion, and demagnetizing fields. Ferrite magnets start to lose strength at temperatures above 250°F, while neodymium demagnetizes around 175°F (higher grades can go up to 200°F). If your application runs hot, a samarium-cobalt magnet will hold its strength longer, or we can add a nickel-copper-nickel coating to neodymium magnets to improve heat resistance. Corrosion is another big one: uncoated neodymium magnets rust easily, and rust creates gaps between the magnet and mating parts that reduce force. All the ring magnets we supply are coated with nickel or epoxy unless specified otherwise, which prevents corrosion and keeps strength consistent over time.
Let’s wrap this up with a real example to tie it all together. Last year, a client who made automatic door latches came to me with a problem: their current ferrite ring magnets were only providing 12 pounds of holding force, which was too weak to prevent the door from rattling in high wind. They didn’t want to change the size of the magnet (it fit perfectly in their latch housing), and they were on a tight budget. We walked through the steps: first, we suggested switching from their 3.5 MGOe ferrite to a 28 MGOe neodymium ring, which was only $0.50 more per unit. Then, we recommended adding a 1mm steel back iron plate, which cost an extra $0.10. Finally, we made sure to magnetize the rings fully during production, which we confirmed with Gauss meters before shipping. The result? The holding force jumped to 32 pounds—more than double their original requirement—without changing the magnet’s physical dimensions. It was a small investment that solved their problem, and that’s the kind of solution I love to help clients find.
If you’re looking to increase the strength of your ring magnets, you don’t have to overcomplicate things. Start by assessing your application’s specific needs: do you need surface flux, or flux in a magnetic circuit? Then, evaluate your material, design, and manufacturing choices to find the lowest-cost, most effective fix. If you’re unsure where to start, I’m here to help. We work with manufacturers of all sizes, from small startups to large industrial companies, to design and supply custom ring magnets that meet their strength requirements without unnecessary costs. Whether you need to tweak an existing design or create something new from scratch, we can provide tested, reliable magnets that deliver consistent performance. Reach out to our team to discuss your project, share your requirements, and get a quote tailored to your needs.
Cube Magnets References
- Campbell, P. (2011). Permanent Magnet Materials and Their Application. Cambridge University Press.
- Rowe, R. (2018). Handbook of Permanent Magnets and Their Applications. CRC Press.
- Magnequench. (2020). Neodymium Iron Boron Magnet Design Guidelines.
- Ferrite Magnet Manufacturers Association. (2019). Ferrite Ring Magnet Performance Specifications.
- American Society for Testing and Materials (ASTM). (2021). Standard Test Methods for Magnetic Flux Density of Permanent Magnets.
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