Magnet Questions

[PapaSmurf]

so my science teacher showed us theses extremely strong magnets called "neodymium". i was realy interested so i bought some via ebay. they came in and i imidietly did someting realy stupid, fucked up my computer screen. the next morning when i turned it on it was back to normal. also, would a faraday mesh wraped around a film canester block some/all magnetic fields? so i can keep it in te same pocket as my cell phone

~PapaSmurf

 

[audioguru]

A Faraday screen blocks radio waves. Magnetism goes straight through it.
You need something that is iron like Mu-metal to conduct the magnetism around the object you want to protect from magnetism.

 

[PapaSmurf]

how expencive?

 

[audioguru]

how expensive?

I don't know if Mu-metal is sold that is good enough to be a good shield for a powerful neodymium magnet.

 

[Roff]

This probably isn't the most powerful permanent magnet commercially available, but the picture is impressive, and **broken link removed** is dangerous.

 

[Someone Electro]

Pricy to $100 for a magnet.

They also must be a head ace to ship becuse they will stick to stuff.

The only use i can think of for this magnet is a railgun.

 

[mcs51mc]

Unfortunately they don't mention any strength in Tesla or Gauss :evil:
So how much is "powerfull", "dangerous", ...

MRI scanners have manget strength between 0.5 and 2 Tesla.
Even more powerful magnets, up to 60 Tesla, are used in research.

It's not because a magnet has huge dimensions that it's a strong magnet. So as long as they don't mention strength in Tesla or Gauss, don't buy anything :wink:

 

[Styx]

Unfortunately they don't mention any strength in Tesla or Gauss :evil:
So how much is "powerfull", "dangerous", ...

MRI scanners have manget strength between 0.5 and 2 Tesla.
Even more powerful electro-magnets, up to 60 Tesla, are used in research.

It's not because a magnet has huge dimensions that it's a strong magnet. So as long as they don't mention strength in Tesla or Gauss, don't buy anything :wink:

just a correction the strongest RAW magnet is only 2.5T to get higher super-conductive electro-mags are needed

 

[Optikon]

Unfortunately they don't mention any strength in Tesla or Gauss :evil:
So how much is "powerfull", "dangerous", ...

MRI scanners have manget strength between 0.5 and 2 Tesla.
Even more powerful magnets, up to 60 Tesla, are used in research.

It's not because a magnet has huge dimensions that it's a strong magnet. So as long as they don't mention strength in Tesla or Gauss, don't buy anything :wink:

Hehe.. my wife designs MRI receiver coils for a living.. you should hear the stories of fire-extinguishers & screw drivers flying across the room at break-neck speeds!

 

[phalanx]

how expensive?

I don't know if Mu-metal is sold that is good enough to be a good shield for a powerful neodymium magnet.

I've never had to use it to shield from ultra powerful fields but you can layer the foil to improve its shielding performance.

Papasmurf, mu metal is quite expensive as can be seen in this link. They have pre-made monitor cabinets that could help you but you are still looking at nearly 7 bills!

**broken link removed**

 

[phalanx]

This probably isn't the most powerful permanent magnet commercially available, but the picture is impressive, and **broken link removed** is dangerous.

Jesus that's a monster! :shock: I have a set of 1" diameter neodymium spheres which can severely pinch you if you are not careful. The average person has an extremely difficult time separating them and they effect monitors from about 5 feet away. I can't imagine how powerful that magnet is! Watch your fingers!

 

[mramos1]

I have 2 brick neodymium magnets at home, they are 1x2.5x6 inches.

I keep them far apart in the garage. They have chips out of them from them going together too hard. I put small bubble packing material between them and no bubbles left. And a bear to twist them apart.

It will project a ball bearing on a rail pretty good though.

 

[spuffock]

Physics teacher " name something that sticks to magnets"

Pupil " Toffee "

 

[Oznog]

The strongest material you're going to find is I think N53. N48 is much more common though and only slightly less powerful. N48 is friggin dangerous!
I had 2 N48 rectangles that got stuck together and it look a long time to figure out how to get them apart.

That's an expression of the magnetic strength of the material used. It doesn't take into account the size of the magnet and thus doesn't describe the overall strength of a particular magnet.

 

[mcs51mc]

What is

an expression of the magnetic strength of the material used. It doesn't take into account the size of the magnet and thus doesn't describe the overall strength of a particular magnet.

:?:

 

[Klaus]

The strongest material you're going to find is I think N53. N48 is much more common though and only slightly less powerful. N48 is friggin dangerous!
I had 2 N48 rectangles that got stuck together and it look a long time to figure out how to get them apart.

OK, tell us how DID you get them apart. You never know when such info comes in handy so, tell us

Klaus

 

[phalanx]

OK, tell us how DID you get them apart. You never know when such info comes in handy so, tell us
Klaus

A padded vice and a floor jack with a block of wood on top by chance?

Trust me it works. Don't ask how I know!