A Toroid Designed to Have a Self Contained Field
By: Michael Brand, President & COO
SM Magnetics was engaged to produce a unique toroid magnet with a self-contained and homogenous field. While the design parameters seemed challenging, our engineering team in the U.S. and China were able to develop and design a magnet that far exceeded expectations.
The Magnetic Toroid Design Parameters
The customer request was to develop a toroid magnet that was in the shape of a ring, but looked similar to a donut. George Mizzell, SM Magnetics’ Engineer and Research Guru, determined how the magnetic field needed to be contained, but more importantly, how the part could be manufactured. With the assistance of our manufacturing engineers, the final part was produced, and the above picture shows the end product.
The Magnetics Field
Containing the magnetic field presented challenges due to various manufacturing techniques and requirements. The material is a very high-grade NdFeB, so care and consideration had to be given to all aspects of manufacturing and assembly. Once the entire design was completed, gauss readings showed an external field on the outside diameter of less than 100 gauss. To give perspective to this magnetic field strength, it was unable to magnetically hold a paperclip. These results were far better than expected, and much more than anticipated.
The Application & Research
This magnet is currently being used for R&D by one of our international customers. They will continue to develop tests that provide insight on the uses of contained fields, and how these might be used in various applications. Although the external weak field was a tremendous result, we believe that further develop of this kind of design could yield an even weaker field outside of the toroid.
We appreciate the challenge presented to us by our wonderful customer for this toroid. We have tackled many unique and interesting projects, but this one shows us once again our ability to push the magnetic and manufacturing limits. This is something we have become familiar with everyday.
About SM Magnetics: SM Magnetics is privately owned company, providing assistance with permanent magnets, magnetic design & optimization, engineering support, and production. SuperMagnetMan is the online retail division of SM Magnetics offering neodymium magnets and other materials.