Robotics deep dive: THE MAGNET CHOKEPOINT Every high-torque joint in a humanoid turns on a neodymium-iron-boron magnet, and a motor buried in a hip or a knee runs hot. Heat is what demagnetises NdFeB. The fix is dysprosium and terbium, the heavy rare earths, alloyed in at a few percent to hold coercivity at operating temperature. They are the reason the magnet survives a shift. The number everyone quotes is mining: the IEA puts China at 60% of global mined production of magnet rare earths in 2024. Sixty percent is a share you can compete with: the ore is not rare and it is not only in China. The number that decides anything is the next one in the same report. China was 91% of global refined output, and 94% of sintered permanent magnet production. That gap, 60 to 91, is the whole subject. Mining is digging. Separation is chemistry, and the rare earths are chemically near-identical by design of the periodic table, so you take them apart by running the liquor through hundreds of solvent-extraction stages in series, each stage nudging the mixture a fraction of a percent toward pure. It is slow and capital-heavy, and it concentrates thorium in the tailings. Thorium is radioactive. The tailings pond is what a Western separation project actually gets fought over, and that fight does not run on a budget cycle. How long it takes: Lynas commissioned a heavy separation circuit in Malaysia and produced dysprosium oxide in May 2025, terbium in June. First time either had been separated commercially anywhere outside China, ever. Rated capacity, up to 1,500 tonnes a year. Magnets are one node in a robot's supply chain and not the only concentrated one. It is the node with the longest replacement time. The clock, checked 21 July 2026. China's April 2025 licensing regime on seven rare earths, dysprosium and terbium among them, is still in force; the IEA's account of what it did is that export volumes fell sharply through April and May and carmakers outside China cut utilisation or stopped lines. The October 2025 expansion, which added a 0.1% de minimis rule and a foreign direct product rule reaching magnet technology, was suspended on 7 November 2025 and the suspension runs to 10 November 2026. It has not been extended. In June Beijing put MP Materials and USA Rare Earth on its own control list. The IEA's 2026 outlook has European dysprosium and terbium trading at around five times Chinese domestic prices. That is the price of the truce while it holds.