Coded vs conventional magnets

Not better — different where it counts. A conventional magnet is a bulk force; a coded magnet is a mechanism. Here is the whole comparison, including the one independent measurement on record.

Property	Conventional dipole	Coded / programmable
Field reach	Long — power-law fade; grabs across real gaps	Short — exponential fade (e^−2πz/λ); work under ~2 mm
Force at contact	Baseline	Higher on thin steel and coded mates; “4–5×” is vendor claim
Force curve	One fixed shape	A design variable — can cross zero, change sign, hold detents
Behaviors	Attract / repel	Align, latch, spring, twist-release, key, shear, torque, detent — composable in one part
Stray field	Everywhere — wipes cards, collects swarf	Engineered toward zero beyond ~0.25″ vendor claim
Identity	Any magnet mates with any steel/magnet	Coded pairs ignore wrong partners (lock-and-key)
Cost	< $2 (pair, plain N42 disc)	$10–40 (retail function pair)
Sourcing	Global commodity, thousands of suppliers	One primary IP holder + a few licensees; thin catalog
Where it wins	Reach, price, holding across gaps, motors/generators	Fasteners, closures, connectors, couplings, safety interlocks — anything at contact

The one independent test

K&J Magnetics ran the closest thing to third-party validation this category has: an alternating-pole array out-pulled both a plain array and a Halbach array on a steel plate — 88 lb vs 72–77 lb, built from the same five cubes. That’s the near-field concentration effect measured by someone with no stake in it. It is directional support for the vendor strength claims — at contact, on steel — not a blank check for “5× stronger.”

And Halbach arrays?

The famous cousin. Both are engineered-magnetization multipoles with the same exponential near-field decay. The differences:

	Halbach array	Coded magnet
Pattern	Periodic rotating magnetization	Aperiodic, correlation-designed N/S code
Result	One-sided, uniform flux	Arbitrary spatial force functions
Signature jobs	Motors, MRI, maglev, undulators (Mallinson 1973, Halbach 1980s)	Align wells, twist-release, springs, keys — behaviors a Halbach can’t express
Construction	Usually assembled from discrete magnets	Printed into ONE piece

In the K&J pull test, the simple alternating-pole array beat the Halbach for raw pull on steel — a reminder that for contact force, local flux-closing is the whole game.

Rule of thumb

Need force across a gap, or a dollar magnet? Conventional. Need a behavior — self-alignment, gesture release, a click, a key, a contained field? Coded. The honest engineering summary of the entire category fits in that sentence.

Who owns this idea? The company & history →