Sintered NdFeB magnets are a leading type of permanent magnets used in many industries because they offer high magnetic energy and can be made in compact sizes. Their strength comes from the crystal structure of neodymium-iron-boron, which gives high remanence and resistance to demagnetization. The magnets are made through a careful powder metallurgy process: materials are melted in a protected atmosphere, cooled quickly, and milled into fine powder; during shaping, an external field aligns the magnetic grains to create anisotropy; then high-temperature sintering densifies the material and forms strong grain boundaries. Fine control of grain size, phase makeup, and diffusion at boundaries boosts coercivity and temperature stability, with methods like heavy rare-earth diffusion used to improve performance while managing rare-earth use. Because they corrosion easily, surface coatings such as nickel, epoxy, or multi-layer systems protect them in harsh environments. They are used in EVs, wind turbines, motors, robotics, medical devices, and precision equipment.