neodymium ring magnets

Table of Contents

Neodymium ring magnets are one type of common strong rare-earth magnets with a regular shape. They are circular in shape with a hollow center. They have many applications in the consumer, industrial, scientific, and medical industries. Their common applications can be holding, motors, electronics, sensors, speakers, etc.   


Features of neodymium ring magnets

As a custom neodymium magnet supplier, we can offer large-diameter magnet rings up to 120 mm wide and small magnetic rings with diameters as small as 1.5mm. The inside diameter of the hole can vary to make the ring magnets fit specific applications or for more suitable fitment options.  

neodymium ring magnets

Dimensional identification

Please note that as a neodymium magnet supplier, the identification we use for ring magnets is different from the one for disc shapes 


D for the outer diameter 

d for the inner diameter 

H for the thickness (height)   

If a ring / circular neodymium magnet has a dimension of D10 x d7 x 3 mm, that means its outer diameter is 10 mm, the inner diameter is 5 mm, and the thickness is 2 mm. 


Meanwhile, ring neodymium magnets have 2 types of holes: straight magnet and countersunk holes magnet.  

Straight holes are drilled vertically into the magnets  

Countersunk holes (also called screw holes) include a primary hole and a major hole.   


For ring or circular neodymium magnets with a countersunk hole 

D for the outer diameter 

M for the diameter of the major hole 

If a ring magnet has a dimension of D10 x M7 x 2 mm, that means its outer diameter is 10 mm, the major hole diameter is 5 mm, and the thickness is 2 mm. 

Besides indicating the sizes, it’s always good to include the countersunk angle. 



Using this dimensional identification for custom neodymium magnets will help eliminate unnecessary misunderstandings on both sides about dimensions. 


Available dimensions 

Available sizes for neodymium Ring magnets 

Outer diameters: 1.5 – 300 mm (1/16 – 11 13/16 inches) 

Inner diameters: 0.4 – 250 mm (1/64 – 9 27/32 inches) 

Height: 0.3 – 120 mm (1/64 – 4 ¾ inches) 

Magnetic direction: 100mm (3 15/16 inches) 



These are the possible limits that Osenc can offer.  

If your designs are close to the biggest or smallest values, we need to confirm details case by case. 


The largest ring 

We can produce largest  neodymium ring magnets with blow dimensions: 

Outer diameter 250mm – inner diameter 220mm × height 60mm (4 ¾ – 3 1/8 x 2 3/8 inches) 

Outer diameter 80mm – inner diameter 50mm × height 120mm (3 1/8 – 1 15/16 x 4 ¾ inches) 


The smallest ring 

Osenc can produce the micro neodymium magnets with blow dimensions: 

Outer diameter 1.5mm – inner diameter 0.4mm × height 0.3mm (1/16 – 1/64 x 1/64 inches) 



The thickness should not be too small for ring shapes with large outer diameters 

The wall should not be too thin for larger ring shapes either, which are easy to break. 



Neodymium magnets grades have different grades, ranging from N35 to N55, and they also have high-temperature designs grade for special applications, like H, M, SH, EH, AH. 

You can refer to our introduction to neodymium magnet grades. It will be helpful for you to determine which grade is the most appropriate for you. 

Magnetization Directions

Magnetization directions

Ring magnets can be axially magnetized or radially magnetized, which is actually similar to circular magnets. 

Axially magnetized ring magnets have north and south poles on the 2 planes.  

Radially magnetized ring magnets have north and south poles on the circular side. 



Operational Tips:

1). Neodymium magnets are fragile, brittle, and highly magnetic. So, remember to use them carefully, particularly for large sizes with thin heights.  

2). If the ring neodymium magnets stick together and you cannot separate, do not separate them perpendicularly, but do it horizontally. If you have no idea what it means, you can refer to our article on separating magnets.

3) Better to keep neodymium magnets away from items that can easily be influenced by magnetism, such as monitors, bank cards, computers, TVs, cell phones, etc. 


FREE quotes for custom designs

Osenc can manufacture custom ring neodymium magnets to fit your exact specifications. Always more than happy to help you determine the best solution for your applications 

You can contact us by clicking the Get a Quote button in the top right corner.    


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