Insights
Research on rare-earth magnets and the supply chain behind them, built from public disclosures and plant-floor experience.
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Interactive atlas, updated
Rare-earth magnet supply chain atlas
Who does what, where, from ore to finished magnet. Every major NdFeB and SmCo magnet producer, sintered and bonded, mapped across seven process steps, with projects under construction and a source for every claim.
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Scroll-driven explainer, soft magnetics
The trouble with Hiperco
Iron-cobalt carries about 20% more flux than silicon steel and the data sheet is honest about it. The trouble starts when you cut it: cold work, laser against die, the anneal that decides which alloy you get, and what the cobalt costs.
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Scroll-driven explainer, seven rungs of why
F***ing magnets, how do they work?
A child who has done graduate quantum mechanics asks why a magnet pulls, and then why again, down through domains, exchange and spin to the Dirac equation. With a Got it button on every step and a chart of how far readers get.
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Scroll-driven explainer, rare-earth separation in three acts
Two ways to split rare earths
Chromatography made the first pure rare earths in 1947, solvent extraction took the tonnage business in the 1960s, and chromatography is back. The same small chemical preference, stacked two very different ways, with what each one costs and why the question is open again.
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Short explainer, the grade code decoded
The five-minute guide to magnet grades
N is neo, the number is the energy product, the letters are coercivity. R is Recoma, the samarium cobalt suffixes are mostly branding, and VAC counts in kJ/m³ except when it doesn’t — plus what to put on a drawing instead of a bare grade name.
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Scroll-driven explainer, every curve against sintered
Bonded magnets, type by type
Compression-bonded, injection-molded, extruded, flexible, bonded ferrite, anisotropic HDDR, SmFeN and bonded SmCo, each with what it gives up and what it buys you. Every demagnetization curve is drawn against a sintered NdFeB magnet on the same axes, so the price of a shape you can mold is visible on the figure.
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Interactive flow map, who sends what to whom
Where the material actually goes
A flow map of the rare-earth magnet chain drawn only from relationships that appear in a public document: NdPr from mine to separator to magnet maker to buyer, and the far thinner dysprosium and terbium chain beside it. Ribbon width is volume where a volume is published and a dashed connector where only the relationship is, and the heavy view turns up a finding of its own — both named non-Chinese outlets for heavy rare earths point at Japan.
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Diligence, over years rather than one headline
Keeping score on the magnet companies
How I follow the companies building a magnet supply chain outside China: a ledger of what they promised and when, whether the verb has moved from “will” to “has,” whether a customer could actually buy something, who carries the IP risk, and whether the plan makes sense on a globe. Plus what LinkedIn and the careers page say about the stage a plant is really at.
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Explainer, the number that actually binds
The heavy rare earth bottleneck
Dysprosium and terbium are about one percent of mined rare earths and carry a disproportionate share of what a magnet has to do, which is why every tonnage figure that matters is the one nobody publishes. Why the heavies bind rather than the light ones, what grain boundary diffusion fixed and what it did not, the ion-adsorption quota that has not moved since 2018, and what the projects outside China actually add up to — with a radioactive materials license attached to most of them.
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History, forty years of a supply chain
How China came to own rare earths
Not a master plan, but four moves that compounded: fifteen years of being the cheapest producer, an export tax on the rock and none on the magnet, the 2010 squeeze that taught everyone what the position was worth, and the export licensing since. The Deng quote everybody uses turns out to be doing less work than it appears, and the two charts — mine production since 1985, and dysprosium against neodymium on a log axis — are built from public anchor points only.
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Scrolling explainer, magnet recycling economics
How magnets get recycled
Short loop versus long loop, and post-industrial versus post-consumer scrap — the two choices that decide every magnet recycling business. Where recycled material re-enters the process, what contaminates it, and why the economics live in the harvesting rather than the chemistry.
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Scrolling explainer, choosing a grade
Choosing a magnet
The other explainers cover what a magnet is and how one is made. This answers the question they leave open: given a temperature, a demagnetizing field, a corrosive environment and a budget, which material do you actually buy. Energy product against temperature for every coercivity class, where grain boundary diffusion moves the frontier, and where samarium cobalt stops being a luxury and becomes the only option.
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Method, technical diligence
Is this magnet headline for real?
A new material, a record energy product, a plant announcement — and the question that follows it. Six questions that separate a magnet company from a well-written press release, in the order I ask them: the demagnetization curve first, then who the message is aimed at, how carefully the claim is worded, what the company physically consists of, whether simple questions get simple answers, and what a new material will say about coercivity. None of it needs a laboratory.
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Animated explainer, eleven motor families
How electric motors work
Every motor makes torque by alignment, by reluctance, or by both at once, and which one it uses decides how much magnet it needs. Eleven families in roughly the order they were invented, each one a cross-section you can watch turn — brushed and universal, induction, wound field, the three reluctance machines, steppers, surface and interior PM, and axial flux — with the magnet bill set against what you trade to avoid one, and every current claim footnoted.
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Illustrated explainer, with a live cost model
The NdFeB grade chart, explained
There are roughly two hundred neodymium grades in a full catalog, and every one of them sits at a point on the same two-axis plot. This is why remanence and coercivity trade against each other, what bulk-alloyed dysprosium cost to buy that trade, and how grain boundary diffusion moved the edge of the chart — ending with a live model of the heavy rare earth and what it costs at prices you can edit.
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Reference, magnet fundamentals
Magnet FAQ
Twenty-five questions people actually ask about magnets: how they work, where their energy comes from, whether they wear out, what they do to a phone, and whether any of it is dangerous. Plain answers, written by someone who has made the material.
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Illustrated explainer, magnet fundamentals
What is a magnet?
One word covers three very different things: materials that amplify a field, materials that remember one, and coils that make one from current. This maps the whole family, from iron and silicon steel through ferrite, alnico, SmCo and NdFeB to superconducting coils and the materials still on the drawing board.
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Illustrated walkthrough, thirteen process steps
How magnets are made: mine to magnet
A sintered neodymium magnet passes through thirteen distinct processes between the ore body and the finished part, and each one has to be tuned to the ones on either side of it. This walks the full chain, with an animated figure for every step and the mass yield that survives it.
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Interactive explainer, magnet fundamentals
Reading a B-H curve
Every magnet datasheet leads with four numbers and one plot. This builds them up from empty space, through soft iron, to a sintered NdFeB magnet, so Br, Hcb, Hci and (BH)max each mean something.
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