Every electric vehicle on the road has them. Every wind turbine spinning on a ridge in west Texas has them. Every pair of AirPods, every MRI machine, every hard drive, every guided missile in the Pentagon‘s inventory has them. Neodymium-iron-boron magnets—NdFeB if you’re reading a spec sheet, “neo magnets” if you’re not—are the strongest permanent magnets commercially available, and they are so deeply embedded in modern technology that removing them from the supply chain would be roughly equivalent to removing concrete from construction. You could technically build things without them. You just wouldn’t want to see what you’d get.
The thing is, almost nobody knows how they’re made. The manufacturing process is genuinely fascinating—part metallurgy, part materials science, part geopolitical thriller—and understanding it explains why these magnets are at the center of a supply chain crisis that involves export controls, Pentagon loans, tariff threats, and the kind of great-power competition that used to be about oil and is now about a silvery metal most people can’t pronounce.
What makes them special
A neodymium magnet is an alloy of three elements: neodymium (a rare earth element, atomic number 60), iron, and boron. The compound—Nd2Fe14B—forms a tetragonal crystal structure that was discovered independently by General Motors and Sumitomo Special Metals in 1984, which is the materials science equivalent of two people showing up to a party wearing the same outfit except the outfit happens to reshape global manufacturing for the next four decades.
What makes this crystal structure so magnetically powerful is its exceptionally high magnetocrystalline anisotropy—the atomic-level property that determines how strongly a material resists demagnetization. In plain language: the crystal lattice is shaped such that the magnetic domains align along a single preferred axis with extreme reluctance to flip. The energy density is roughly ten times higher than a standard ferrite magnet, which means a neodymium magnet the size of a quarter can do the work of a ferrite magnet the size of a coffee mug. That size-to-strength ratio is why they ended up everywhere. When you need a powerful magnetic field in a small package—an EV motor, a drone, a missile guidance system, an earbud—there is no practical substitute.
How they’re actually made
The manufacturing process is powder metallurgy, and every step matters. Screw up the particle size, the alignment pressure, or the sintering temperature by a small margin and you get a mediocre magnet instead of a great one. This is not an industry where you can wing it.
It starts with strip casting. The raw materials—neodymium (often with some praseodymium substituted in because it’s cheaper and chemically similar), iron, and boron, plus small additions of dysprosium or terbium for high-temperature applications—are melted together in a vacuum induction furnace at around 1,300°C. The molten alloy is poured onto a rapidly spinning, water-cooled copper roller, which solidifies it into thin strips. The rapid cooling is critical: it produces a fine-grained microstructure that’s optimized for the next step.
Those strips go through hydrogen decrepitation—you expose them to hydrogen gas, which diffuses into the grain boundaries and causes the alloy to crack apart into coarse chunks. This is nature doing the first stage of size reduction for you. From there, the chunks go into a jet mill operating in a nitrogen atmosphere, where high-pressure gas streams grind the material into an extremely fine powder with an average particle size of about 3 microns. That’s roughly the size of a red blood cell. The nitrogen atmosphere prevents oxidation, which would ruin the magnetic properties—neodymium is ferociously reactive with oxygen, which is also why the finished magnets need protective coatings, but we’ll get there.
Now comes the step that makes or breaks the magnet: magnetic field alignment and pressing. The powder goes into a mold, and a powerful external magnetic field—several tesla—is applied. This field physically rotates the tiny crystalline particles so their easy magnetization axes all point the same direction. The aligned powder is then compressed under enormous pressure. The alignment quality during this step directly determines the magnet’s maximum energy product—the BHmax value that shows up on the spec sheet and tells an engineer how much magnetic work the magnet can do per unit volume. A poorly aligned magnet with the exact same chemical composition will be measurably weaker than a well-aligned one. The process matters as much as the recipe.
The compressed “green compact” is then sintered in a vacuum furnace at approximately 1,050°C. Sintering fuses the powder particles together without fully melting them—it’s the difference between welding and soldering, conceptually—creating a dense, solid block with the internal crystal alignment locked in place. After sintering, the magnet goes through a two-stage annealing process at around 900°C and then 600°C, which relieves internal stresses and dissolves unstable phases that would degrade performance over time.
At this point you have a block of sintered NdFeB that is extremely hard, extremely brittle, and not yet the shape anyone needs. Machining comes next—diamond-tipped saws and grinding wheels cut the blocks into the precise geometries required for specific applications: arcs for motors, discs for speakers, rings for sensors. This is delicate work because the material shatters like ceramic if you look at it wrong. The kerf loss (material wasted in cutting) is a meaningful cost factor, especially when neodymium oxide costs upward of $70 per kilogram.
Then: coating. Unprotected NdFeB corrodes aggressively. The neodymium-rich grain boundary phase reacts with moisture and oxygen, forming hydroxides that literally cause the magnet to disintegrate over time—structural failure from the inside out. The standard solution is a multi-layer nickel-copper-nickel electroplating, though epoxy coatings, zinc plating, and parylene are used depending on the application environment.
Finally, the magnet is magnetized. A pulse magnetizer blasts it with a field of approximately 5 tesla, which saturates the aligned domains and produces a permanent magnet ready for installation. The whole process, from raw oxide to finished magnet, involves dozens of precision-controlled steps, and the yield at each stage matters. This isn’t assembling a product. It’s growing one.
Why this is a geopolitical problem
China produces roughly 85% of the world’s NdFeB magnets. Not 85% of the neodymium—85% of the finished magnets. Japan and Vietnam account for most of the rest. The United States, as of early 2025, produced approximately zero sintered NdFeB magnets at commercial scale. That’s a supply chain that has the resilience of a house of cards in a wind tunnel, and everyone involved knows it.
The concentration isn’t accidental. China made a strategic bet on rare earth processing decades ago—Deng Xiaoping reportedly said in 1992 that the Middle East has oil and China has rare earths—and then spent thirty years building out the mining, separation, refining, alloying, and magnet manufacturing infrastructure while everyone else was content to buy cheap finished products. The result is a vertically integrated supply chain that’s extraordinarily difficult to replicate quickly, because it’s not just the magnet factory you need. It’s the solvent extraction plant, the oxide separation facility, the metal reduction furnace, the alloy production line, and the workforce that knows how to run all of it. Each step has its own chemistry, its own equipment, its own failure modes.
The consequences of this concentration became concrete in April 2025, when China imposed export licensing requirements on dysprosium, terbium, and finished magnets. Export volumes reportedly dropped roughly 74% in May compared to the prior year. These aren’t abstract tariff games—dysprosium is the element that gives NdFeB magnets their high-temperature performance, and without it, the magnets in an F-35’s flight control actuators, an MQ-9 Reaper drone’s guidance system, or a Virginia-class submarine’s propulsion motor would lose their magnetic properties at operating temperatures. The Pentagon noticed.
The U.S. response has been a scramble. MP Materials—which operates the Mountain Pass mine in California, the only active rare earth mining operation of scale in the country—opened a magnet manufacturing facility in Fort Worth, Texas, in 2025. They began trial production of automotive-grade sintered NdFeB magnets late that year, with a target capacity of about 1,000 metric tons per year. For context, global production is somewhere around 220,000 to 240,000 metric tons annually. So the Fort Worth facility, at full capacity, would represent roughly 0.4% of global supply. It’s a start. It’s not a solution.
The Pentagon, meanwhile, awarded a conditional $620 million loan to Vulcan Elements and ReElement Technologies to scale domestic magnet production for defense applications. President Trump publicly threatened 200% tariffs on Chinese goods if Beijing restricted rare earth magnet shipments. The EU passed the Critical Raw Materials Act. Everyone is suddenly very interested in a supply chain they ignored for thirty years.
Why there’s no easy substitute
The reason this matters so much is that there is no drop-in replacement for NdFeB in most high-performance applications. Ferrite magnets are cheap and abundant, but they’re roughly one-tenth the energy density—you’d need a motor ten times the size to produce the same torque, which defeats the purpose of using permanent magnets in the first place. Samarium cobalt magnets handle high temperatures better but cost significantly more and use cobalt, which has its own supply chain problems centered on the Democratic Republic of Congo. Researchers have explored ferrite-based alternatives, iron nitride, and manganese-based compounds, but none have come close to NdFeB’s combination of magnetic strength, manufacturability, and cost at scale.
The substitution problem is especially acute in two sectors: electric vehicles and wind turbines. A typical EV traction motor uses 1 to 2 kilograms of NdFeB magnets. A direct-drive offshore wind turbine—the kind being deployed at scale in the North Sea and off the U.S. Atlantic coast—uses roughly 600 kilograms per megawatt of capacity. If you’re planning to electrify the global vehicle fleet and simultaneously triple offshore wind capacity by 2040, you need a lot more neodymium than currently exists in the processing pipeline. The bottleneck isn’t the ore. It’s the processing, the separation, and the magnet manufacturing—and those bottlenecks are sitting in a country that has demonstrated a willingness to use them as leverage.
This is the kind of constraint that doesn’t show up in the optimistic energy transition models, and it’s the kind of thing that makes the difference between a plan that works on a slide deck and a plan that works on a random Tuesday when the supply ship doesn’t arrive.
We cover neodymium magnets—along with 35 other critical elements and minerals, from lithium to uranium to gallium nitride—across 36 lectures in our Rare Earth Elements & Critical Minerals course. If you want the full supply chain story, from the Bayan Obo mine to the inside of an F-35 actuator, that’s where it lives.