Since the beginning of the 21st century, China's sintered Neodymium magnet manufacturing and supply exceed quickly the development in developed countries such as Japan, the United States, and Europe. As of 2022, China occupy a dominant position throughout the global Neodymium magnet supply chain, and the major Neodymium magnet producers are China (92%), Japan (7%), Vietnam (1%), Germany (<1%) and a few other countries with relatively limited capacity. Among several production locations in China, Ningbo is famous for manufacturing high quality Neodymium magnets used in the electric motors, loudspeakers, sensors, magnetic assemblies, etc. In recent years some developed countries are taking some measures to encourage domestic production of rare earth mining and then rare earth Neodymium magnet production so as to improve supply chain resilience.
In fact, sintered Neodymium magnet production belongs to powder metallurgy and then mechanical processing. In the powder metallurgy stage, a suitable composition of raw materials is pulverized into fine powder, pressed and heated to cause densification via liquid phase sintering to get the raw magnet blocks with required magnetic properties and physic properties. After sintering, the raw magnet blocks are machined according to specific shape and size, surface treated, magnetized, packaged and shipped.
Almost all Neodymium magnets are supplied magnetized to saturation. Sintered Neodymium magnets are anisotropic and can only be magnetized along the orientation direction which is fixed in the pressing process. It’s very common to magnetize round magnets axially or diametrically and magnetize rectangular magnets through thickness. Magnetizing fixture is required to work with the magnetizer to reach multipole magnetization directions in the magnetization process. Sometimes radial magnetization and skewed magnetization is needed in some special applications.
Axially Magnetized
Axially Multipole Magnetized
Diametrically Magnetized
Radially Magnetized
Radially Multipole Magnetized
Skewed Magnetized
Neodymium countersunk magnet, also called countersunk rare earth magnet, countersunk disc magnet or countersunk ring magnet, combines strong adsorption and convenient installation functions. The countersunk hole structure enables its easy use in the assembling process.
Neodymium block magnets are usually square and rectangular block shaped, which are the most common shape of Neodymium magnet. Usually we call them rare earth bar magnets, magnetic blocks, Neodymium bar magnets or rectangular Neodymium magnets. The strong block magnets are always used in industrial markets and small blocks may be used as craft magnets.
Neodymium ring magnet refers to the Neodymium magnet in the ring or donut shape. Sometimes we also call it NdFeB ring magnet, Neo magnetic ring, rare earth ring magnet or ring Neodymium magnet. This design offers unique advantages for specific applications where mounting or assembly requirements dictate the need for a centralized void. Therefore, the ring shaped magnet is very common and easy to find in many application markets.
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