# magnet emergency



## CM Cubes (Feb 18, 2018)

I purchased 1000 n35 magnets and 200 n50 from the same sellar. They are all 4mm x 2mm. When I opened the package, I accidentally hooked them together. Does anyone know how to sort the two. I’ve looked everywhere online with no progress. Help would be appreciated


----------



## Sue Doenim (Feb 18, 2018)

I think you could test the strength of each one individually, but I'm not sure if there's enough of a difference to accurately tell, and it would definitely be tedious.


----------



## xyzzy (Feb 18, 2018)

No idea whether this'll work, but you can try this:

1. Find a flat, even, and relatively smooth surface (e.g. a sheet of paper).
2. Fasten one "reference" magnet to the surface with tape/glue/whatever. (The stronger this reference magnet is, the better.)
3. Now take 25 or so magnets from the bunch you need to sort (randomly—you need to have some N35s and N50s among the magnets you choose) and, for each one of these, label them, then place them on the surface and slowly move them towards the reference magnet; measure and record the distances at which the magnetic pull overcomes friction.
4. The resulting distribution should be bimodal: there'll be around 3-5 magnets that only attract at a significantly lower distance. Those are the N35 magnets, and the rest are N50.
5. Repeat for the remaining 1175 (lol) magnets, but now that you know what the threshold distances for the N35 and N50 magnets are, this should go a lot faster. (You won't need to label these either; just throw them together with the other N35/N50 magnets as you sort them.)

(caveat: this will only work if the difference is pull strength between N35 and N50 is sufficiently large; I don't know whether this is the case. on the other hand, if the difference isn't large enough to distinguish by this method, maybe it doesn't matter which ones end up being in the cubes you magnetise!)


----------



## DannyEarp (Feb 18, 2018)

Can't you just get some metal filings and paper and see a difference in their magnetic fields?


----------

