NdFeB ring magnet https://www.zhijiangmagnet.com/
A neodymium magnet was discovered in 1982 by Masato Sagawa of Sumitomo Special Metals, Japan. The magnetic energy product (BHmax) of this magnet was larger than that of the samarium cobalt magnet, and it was the substance with the largest magnetic energy product at that time in the world. Later, Sumitomo Special Metals developed the powder metallurgy process.
