Choose a behavior, then check the numbers.
The datasheet figures, materials and limits, the demo-kit contents, and the honest path to parts in hand. Figures come from CMR datasheets (controlled documents) or vendor marketing — no independent third-party force lab has published a full test suite, and we flag that as a gap.
If your design needs…
| Your requirement | Behavior | Key numbers | Watch out for |
|---|---|---|---|
| Parts that find their own seat | Align | <1 mm registration; ~10× force collapse off-center (US 7,800,471) | Engages only in the last few mm — don’t expect long-range capture |
| Hold hard, release with a gesture | Twist / slide-release | 1002300: 49 N attract → 57 N repel at ±20°; ~4 mm re-latch; ~$35/pair. Slide version 1002289: 6 mm throw | Reaction torque needs a D-flat or keyed bore |
| A contactless spring or standoff | Spring | 1002288: ~25 N peak repel → 0 by ~15 mm | Earnshaw: must run constrained on a pin/shaft |
| Connectors with identity | Key | Matched+aligned = strong; else ≈0. Rejection ratios unpublished | Rejection is analog — strong discrimination, not literally zero |
| Grip that won’t disturb electronics | Contain field | Work at <2 mm gap; “near zero beyond ~0.25″” [vendor] | The same containment kills reach — by design |
| Sideways stiffness / torque across a gap | Shear / torque | “2–8× shear” [vendor]; US 9,219,403 | Independent shear data: none published |
| Maximum raw pull on thin steel | High-force attach | Max-Attach® (IMI): 28 sizes, 8–96 lb; “2× pull” [vendor]; K&J independent: alternating array 88 lb vs plain 72–77 lb | “250 lb vs 40 lb” claims: single-vendor, unverified |
The physical envelope
The honest on-ramp
Feel it: the demo kit
Demo Kit 1002031 — $149 at polymagnet.com: High-Force, Controlled-Field, conventional-reference, Spring, Latch, Twist-Release, Spring-Latch and Rotational-Align pairs, plus a steel plate and green viewing film to see the printed patterns. Individual demo pairs run $16–$52; function pairs $7–$45. There is no substitute for holding a twist-release.
Buy at polymagnet.com →Prototype a function
Pick from the software catalog of standard functions, or engage CMR’s custom-solutions path — pattern design, prototyping (“minutes to hours, not months” [vendor]), force testing, training. Serious programs can license Polyvision, the maxel-level design CAD with real-time field visualization, at $4,999/yr — or buy magnetizing hardware (Polydesk / Polylab / Polymag 6.2; desktop printers have run ~$45k).
Plan the supply chain
Catalog parts retail via polymagnet.com, Amazing Magnets and PolarStar; high-force industrial variants via Industrial Magnetics (Max-Attach®). Budget honestly: coded pairs cost $10–40 against under $2 for plain magnets — the business case lives in the springs, catches, fasteners and assembly steps the one part deletes. And note the single-source reality in your risk register.
Before you commit a design: read the full physics — decay math, Halbach comparison, correlation coding — at the companion encyclopedia.
multipolemag.com →