The geography of magnet supply
The exposure starts upstream of your supplier. China dominates rare earth refining and produces the large majority of the world's sintered NdFeB magnets; heavy rare earths (dysprosium, terbium — the ingredients of high-temperature grades) are even more concentrated. Since 2025, export licensing on rare earth materials and magnet products has been an active policy instrument, adding a permitting clock to shipments that has nothing to do with factory capacity — the full supply-chain map is in the rare earth supply chain guide.
Three consequences for network design:
- Your true supply chain is deeper than your PO. A U.S. trader, a Vietnamese assembler, and a German motor supplier can all bottleneck on the same Chinese refinery. Map parts to manufacturing sites and material origin, not to invoice addresses.
- High-temperature grades carry extra concentration risk. Dy/Tb-bearing classes (SH/UH/EH) are the most exposed to both price spikes and licensing friction — worth knowing which of your parts use them.
- Ex-China capacity is growing but scarce. It reduces policy risk at a price premium and with narrower capability — a portfolio component, not yet a wholesale replacement.
Anatomy of a magnet lead time
A custom sintered magnet's quoted lead time decomposes into stages, and knowing which stage dominates tells you what an expedite can and cannot compress — the full breakdown is in the MOQ & lead-time guide:
| stage | compressible? | notes |
|---|---|---|
| Tooling (new parts) | Slightly | Pressing dies and magnetizing fixtures are the long pole on first orders; premium tooling slots exist |
| Material & pressing/sintering | Barely | Furnace campaigns batch by grade; a licensing delay lands here and no expedite fee moves it |
| Grinding & coating | Somewhat | Plating batches can split; partial shipments from the first batch are the honest expedite |
| Magnetizing & inspection | Yes | Fast when fixtures exist; this is also where documentation is generated — don't let it be skipped to save days |
| Freight & customs | Yes — at a price | Ocean-to-air swaps buy weeks; customs holds on classification or licensing paperwork are the wildcard |
| Domestic stock | — | Days, not months — the reason stock conversion is a continuity strategy, not just a cost play |
Logistics: UN 2807 & mode choice
Magnetized material is a classified dangerous good in air transport (UN 2807) when the external field at package surface exceeds IATA thresholds — which means packaging, measurement documentation, and carrier acceptance are part of your lead time, not an afterthought. The air shipping guide covers the rules; the planning takeaways:
- Small parts in small quantities usually ship unrestricted with basic packaging care; the topic becomes real with large magnets, high piece counts, and assemblies.
- Shielded packaging adds weight and cost to air shipments — budget both when modeling an ocean-to-air expedite, or the “two-week save” arrives over budget and re-palletized.
- Unmagnetized shipment sidesteps the classification entirely. If magnetizing can happen domestically or post-assembly, air freight becomes ordinary freight — a design-stage decision with logistics payoff.
- Put the mode plan in the RFQ. Packaging method, field measurement docs, and freight assumptions belong in the quote if air is ever in your plan, per the RFQ guide.
Inventory strategy
Because magnet lead times are long, lumpy, and policy-sensitive, inventory is the cheapest continuity tool in the kit — if it's structured deliberately:
Disruption signals to watch
Magnet supply rarely breaks without warning — the warnings are just in unfamiliar places:
- Policy calendar: tariff modification rounds and export-control announcements — each one moves landed cost or adds licensing steps with weeks of notice. Assign an owner; the tariffs guide explains what each instrument does to your cost stack.
- The rare earth index: sharp Nd/Pr or Dy/Tb moves precede quote changes and allocation behavior by weeks — trend sources in the price volatility guide.
- Supplier behavior: stretching quoted lead times, hedged answers on material availability, requests to re-open fixed pricing, releases slipping against blanket schedules — each is data before it's a problem.
- Documentation degradation: certs arriving late, lot numbers getting sloppy, a different factory name on the paperwork — the classic tell of a silent resource under supply stress, per the qualification guide's red flags.
The disruption playbook
When supply breaks, sequence matters:
- 1 — Size the gap in true dates. Confirmed supplier dates including licensing and freight, against real consumption — not the MRP netting that assumes the old lead time.
- 2 — Sweep for existing material. Supplier finished goods and WIP, distributor stock, sister-plant inventory, and stock sizes that engineering can approve as temporary substitutes — a same-grade catalog part with a deviation is often the fastest bridge; check U.S. stock before booking charter freight.
- 3 — Split and fly what exists. Partial shipments from completed process stages, air freight on the split lot — with the UN 2807 packaging math from section 03 done before promising dates upstream.
- 4 — Protect quality while expediting. Disruptions are when substituted grades and skipped documentation slip through. The acceptance criteria and lot traceability from the documentation guide are most valuable exactly now.
- 5 — Convert the lesson. Every disruption ends with a structural change — a buffer resized, a part converted to stock, a second source scored, a clause added — or it repeats on schedule.
Designing continuity in
The durable version of this job is making the network shock-tolerant rather than reacting well:
- Score parts for continuity treatment using the second-sourcing worksheet: dual-qualify the few line-stoppers that justify duplicate tooling, buffer the middle, design out the long tail.
- Hold the four forms of supply security in view — second source, buffer inventory, tooling ownership with release rights, and stock-size fallbacks — and make sure every critical part has at least one of them on purpose.
- Keep qualification files current. A second source that hasn't run production tooling in two years, or a reference sample set nobody can find, is continuity theater.
- Put continuity in the contract: site-change notification, tooling release terms, allocation priority, and who absorbs duty and licensing changes — agreed before the bad week, when everyone is still friendly.