Rare-earth magnets, from the plant floor to the investment memo.
Peculiar Materials is David Maybury's independent consultancy on magnetics, magnet manufacturing, and rare-earth supply chains. I've run a magnet plant, helped build another, and provide technical and financial diligence for investors.
Email David What I doWhat I help with
- Magnetics and magnet manufacturing
Grade selection, magnetic performance and thermal limits, and process engineering for sintered NdFeB and SmCo: plant design, equipment selection, ramp-up, yield and scrap, and cost models grounded in how a line actually runs.
- Rare-earth supply chains
Sourcing strategy from oxide through metal, alloy, and finished magnet. Supplier qualification, heavy rare-earth exposure, concentration risk, and what export controls mean for your program.
- Technical and financial diligence
Independent review of magnet and rare-earth companies for investors: process maturity, capex and ramp assumptions, unit economics, and whether the plan holds up on a factory floor.
What that looks like in practice: a complete example diligence report, for a company that does not exist
Mine to motor
Each stage of the rare-earth chain constrains the next. My core expertise is the three highlighted stages, from metal through alloy to finished magnet.
- Ore
- Concentrate
- Separated oxide
- Metal
- Alloy
- Magnet
- Motor
See who performs each stage, country by country, in the supply chain atlas
Insights
Long explanations of things that are hard to explain, written for people who have to make decisions about magnets without ever having made one. Free, animated, and sourced.
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Interactive — 143 organizations, 27 countries
Rare-earth magnet supply chain atlas
Who does what, where, from ore to finished magnet. Click a process step and the countries that perform it light up; the detail view gives every producer’s stage coverage, operating status and source.
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Illustrated walkthrough
How magnets are made: mine to magnet
Thirteen processes stand between an ore body and a finished magnet, and each one has to be tuned to the ones on either side of it. An animated figure for every step, and the mass yield that survives it.
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Reference
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.
Also here: reading a B-H curve, how electric motors work across eleven families, what a magnet actually is, and the NdFeB grade chart explained. All insights
Tools
Working calculators for people who make and specify magnets. Each one runs entirely in your browser — nothing you type is sent anywhere.
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Sourcing and landed cost — beta
Landed cost estimator
Describe a sintered NdFeB magnet and see what it lands at from five places at once, split into material, processing, tooling, logistics and duty. It compares regions; it does not price your supplier.
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Magnet performance
Magnet field and temperature calculator
A disc, ring or block in any of 135 grades: what a gaussmeter reads above it, where the shape puts the operating point, and how far the demagnetization curve has to move before the loss stops being reversible.
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Magnet machining
Magnet machining yield calculator
Describe the magnet, the block you can press, and what your machines can hold. It works through every legal route from one to the other and ranks them by material yield, machine time and cost per good part.
Background
I'm David Maybury. I've spent more than two decades in magnetics, with a BS and MS in Materials Science and Engineering from Georgia Tech. Magnets I've made have gone into Formula 1 cars, artificial hearts, oil drilling tools, and commercial aircraft.
I've run a magnet plant, helped build another, and led production and operations for companies that depend on them. That's what I bring to every engagement: a clear read on what a process can do, what it will cost, and how long it takes to get there.
Off the clock I play competitive trivia. I'm a Jeopardy! champion, winning my game in the 2023 Second Chance tournament and reaching the finals.
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Calnetix Technologies
Vice President, Operations
Operations for high-speed electric motors, generators, magnetic bearings, and drive systems.
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Anduril Industries
Head of Production, Missiles
Led missile production, including the full Barracuda product family.
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MP Materials
Senior Director, Manufacturing Technology
Helped build Independence, MP's greenfield rare-earth magnet plant in Fort Worth, Texas, bringing magnet manufacturing technology back to the US.
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Arnold Magnetic Technologies AG
General Manager, Lupfig, Switzerland
Ran Arnold's Swiss operation.
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Investor diligence
Technical and financial diligence
Extensive diligence work for investors evaluating magnet, rare-earth, and materials companies.
Media
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Podcast guest
Jay & Miles X-Plain the X-Men — Ep. 500, “People Who Stick Together”
Guest appearance discussing the science of magnetism — and whether Magneto’s powers hold up — alongside Josephine Riesman.
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Podcast feature
Inside Jeopardy! — “Who is David Maybury?”
Featured profile on Inside Jeopardy!, the official Jeopardy! podcast.
Tell me what you're building or evaluating.
A short note on the question, the timeline, and who's asking is enough to start.
david@peculiarmaterials.comPrivacy
What this site records, why it is allowed to, and how to make it stop.
- Who is responsible
Peculiar Materials LLC is the data controller for this site. Write to david@peculiarmaterials.com about anything on this page.
- What is recorded
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When you arrive here from another website, a count of the linking site and the page you landed on. That count carries no address and nothing that identifies you.
When you press Got it on a step-by-step Insights page, one more in a count for that page and that step. That count carries no address, no time and nothing that identifies you, so there is nothing in it to delete.
When you run a routing in the yield calculator, one record holding the time, your IP address, the network that address belongs to, an approximate country, region and city, and a reverse-DNS name if there is one. It holds nothing you typed into the calculator: that work stays in your browser and is never sent.
No cookies, no advertising, no tracking across other sites, no profiling, and no automated decisions about anyone.
- Why I am allowed to
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My legitimate interests under Article 6(1)(f) of the UK and EU GDPR: understanding which organizations use a free engineering tool I publish, how heavily, and where from, and keeping the site available and free of abuse. That tells me whether the work is worth continuing and who it is reaching.
I weighed that against your interests. The record is small, it holds none of your engineering work, it is never used to target or advertise to you, and the part that identifies you is deleted well before the rest. If you object, it stops — see below.
- How long it is kept
Your IP address is deleted after 30 days. The rest of the routing record, no longer tied to an address, is deleted after 6 months. Referrer counts are deleted after 26 weeks. All three sweeps run every day, automatically, not on request.
- Who else sees it
Cloudflare hosts the site and stores these records on my behalf, as a processor. Nothing is sold, shared, or handed to anyone for their own purposes. Reverse-DNS lookups go to Cloudflare's public resolver.
- Your rights
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You can ask for a copy of what is held about your address, ask for it to be deleted, or object to it being recorded at all, by emailing david@peculiarmaterials.com. Ask within 30 days of your visit, while there is still an address to look it up by. There is no charge and no form.
To opt out before the fact, turn on Global Privacy Control in your browser. I honor it: the calculator works exactly the same and nothing is written down.
If you are in the UK or the EU and think I have this wrong, you can complain to your national data protection authority — in the UK, the Information Commissioner's Office.