Magnet Question

[dizos]

Can anything block a magnetic field? Magnets are so useful, but the potential of screwing up credit cards, hard drives etc makes them dangerous to use for EDC. It would be awesome if you could shield them.

-- Dizos

 

[gajinoz]

Can anything block a magnetic field? Magnets are so useful, but the potential of screwing up credit cards, hard drives etc makes them dangerous to use for EDC. It would be awesome if you could shield them.

-- Dizos

A metre or two of lead should do the trick.

 

[grnamin]

Here's something about magnetic shielding:
http://www.tpub.com/neets/book1/chapter1/1j.htm

 

[Gollnick]

Can anything block a magnetic field?

No, in fact very few materials do.

 

[Gollnick]

MuMetal is the most common answer for magnetic shielding, but it's expensive and has some drawbacks of its own.

http://www.mushield.com/
http://www.lessemf.com/mag-shld.html

 

[yuzuha]

Mu-metal and its relatives (permalloy etc.) are the best but just plain sheet iron can do a pretty good job. I ordered a bunch of NdFeB supermagnets and they just made a little box out of 2 sheet metal "U"s that just fit inside the cardboard shipping box. Barely any of the magnetic field leaked out.

 

[mycroftt]

Depends on the magnet. Weak ones are easily shielded. Strong ones, like the spinning magnetic core of the earth, can't be shielded by a planet-sized wrapper.

I never carry my NdFeB magnets anywhere near my credit cards - not even on the same side of my body but I have no fear of handling them (carefully).

 

[yuzuha]

Yes, they should be handled carefully. I have a 1"x1" cylender magent on the freezer door of my fridge One day I was bending down to get something out from behind the milk and felt my head suddenly being jerked toward the freezer door... ripped the big tortoise-shell hairpin I usually wear right off my head along with a couple of hairs (alas, not gray ones )

Here's some fun stuff on them
http://www.dansdata.com/magnets.htm
http://www.dansdata.com/magnets2.htm