Shipping Magnets by Air: IATA Rules Explained

Aircraft carry magnetic compasses and magnetometer-based sensors, and a sufficiently strong stray field in the cargo hold can deflect them. For that reason, "magnetized material" is listed as a Class 9 (miscellaneous) dangerous good in the IATA Dangerous Goods Regulations — UN 2807 — with the classification based entirely on the magnetic field measured outside the package, not on what's inside it.

That last point is the key to the whole topic: the regulations don't care how strong the magnets are — they care how much field escapes the box. A crate of powerful magnets packed with proper shielding and flux-cancelling arrangement can ship completely unrestricted, while a single large magnet tossed in a plain carton may be forbidden from aircraft altogether.

The IATA DGR sorts a package into one of three buckets based on measured field strength at defined distances from the package surface:

Numbers worth memorizing: 0.002 gauss at 2.1 meters is the line between "just a box" and regulated cargo. For context, that is a very small field — roughly 1/250th of the Earth's own field — which is why unshielded packages of even modest magnets can trip the limit, and why packaging technique matters so much.

Classification is determined on the packed, ready-to-ship package:

• Milligaussmeter survey. A calibrated meter measures the field at 2.1 m (and if needed 4.6 m) from each package surface, with the package rotated to find the worst-case orientation. The highest reading governs.
• Compass deflection test. The traditional field method: a magnetic compass at the specified distance must deflect less than the allowed amount as the package is rotated. It's the origin of the numeric limits and still a recognized check.
• Worst case rules. Because package orientation in an aircraft is uncontrolled, the measurement must capture the maximum external field in any direction — a package can't "point its poles at the floor" to pass.

Reputable magnet suppliers perform and document this survey on outbound air shipments, and can provide the measurement record if your forwarder or carrier asks for evidence that a shipment is not restricted.

Getting a magnet shipment under the unrestricted threshold uses three techniques, usually in combination:

1 — Flux cancellation by arrangement

Magnets packed in attracting pairs or stacks (N-to-S) form closed loops whose external fields largely cancel. Alternating orientation layer by layer in a carton dramatically reduces the net field compared with all magnets aligned the same way. This is free — it's just packing discipline.

2 — Steel keepers and shunts

Soft steel plates ("keepers") across the poles give flux a low-reluctance return path inside the package instead of through the air outside it. Pot magnets and magnet-on-steel assemblies are often self-keeping.

3 — Distance and shielding layers

Field falls rapidly with distance, so centering the magnetic payload in a larger box with spacing does real work. For what remains, steel-lined cartons or sheet-steel wraps absorb and redirect stray flux. Heavy shipments of large magnets may use purpose-built shielded crates.

When a package can't practically be brought under the threshold, it ships as UN 2807 Class 9 magnetized material. What that involves:

• The Magnetized Material handling label (blue compass-and-field design) on the package.
• Compliance with the applicable IATA packing instruction for magnetized material, including the requirement that the field not exceed the forbidden level at 4.6 m.
• Shipper's documentation identifying the consignment as magnetized material — air waybill notation and, per carrier requirements, dangerous goods paperwork prepared by DG-trained staff.
• Carrier acceptance — Class 9 magnetized material is widely carried, but individual airlines and integrators (FedEx, UPS, DHL) apply their own acceptance rules, service limitations, and fees. Check before booking.

Practical cost note: regulated shipments carry DG fees, restricted routing options, and longer handling times. For recurring volume, it is almost always worth engineering the packaging to ship unrestricted instead.

This is why magnet supply chains usually look the way they do: production quantities move by ocean, urgent quantities move by air with engineered packaging, and domestic distribution runs by ground with no magnetization constraint at all.

• Expect packaging line items on air quotes. Shielded packaging for strong magnets is real material and labor; a supplier quoting air freight on large magnets without mentioning it may not have thought it through.
• Expedites may be slower than you think. If a hot shipment trips the forbidden threshold, it must be repacked — build a day of margin into air-freight expedites of large or numerous magnets.
• Consider unmagnetized shipment. Oriented-but-uncharged magnets have no external field and ship as ordinary freight by any mode. If magnetizing can happen domestically or post-assembly, this eliminates the entire topic — common for rotor programs. See Magnetization Directions for how orientation and charging separate.
• Small orders usually aren't an issue. Typical sample quantities of small magnets, packed with basic care, measure below the unrestricted threshold. The topic becomes real with large individual magnets, high piece counts, and assemblies.
• Put it in the RFQ. If you'll need air shipments, say so — packaging method, measurement documentation, and freight assumptions belong in the quote. Our RFQ preparation guide covers where.

Radial Magnets handles magnetized-material packaging and documentation on air shipments as standard practice — if your program needs routine air freight, tell us at RFQ and we'll quote the packaging approach with the parts.