Neodymium iron boron

[Xplorer877]

These will destroy your fingers if you're not careful.

 

[12dstring]

wouldn't want a finger between them!

The largest I have is a 1" cube, but they look bigger?

They so much fun ;D but I used to get some many marks on my hands removing them from hard drives when they'd suddenly snap together on a piece of skin.

 

[sportcoupe]

wouldn't want a finger between them!

The largest I have is a 1" cube, but they look bigger?

They so much fun ;D but I used to get some many marks on my hands removing them from hard drives when they'd suddenly snap together on a piece of skin.

Hard drives have rare earth magnets in them? Where? Got any pictures? Size?

I ask because I have maybe 30-40 drives laying around.

 

[12dstring]

Yep! The big silver part in the bottom right houses some NdFeB magnets, it's what makes the actuator arm be able to move so fast.

The size and amount vary depending on the drive, but even the smaller ones (about half an inch square in size) will happily leave little blood blisters if you catch some skin between two of them.
I've taken apart about 20 for this purpose, 30-40 would be great fun the platters make good mirrors too.

 

[Montana64]

I ordered 4 from ebay 1"x 1" cylindrical shaped. The came in the mail on Monday, i opened the package and they were packaged side by side in a square formation with a slim piece of plastic separating them. As i was removing one of them, another one jumped to it, and the only way i could separate those two was by laying them down on the edge of a counter top with one extending over the edge and then pushing down and sliding them apart. Was not easy at all. They are rated N50 and have 100lbs pull force for each one. They definately will maim you if you are not extremely careful with them!!!


Ted

 

[thesk8nmidget]

about how thick of wood do you think these 1 inch ones could keep holding together?

 

[Montana64]

im sure i could hang a full sheet of 1/2 inch plywood to some iron beams without difficulty.

Ted

 

[Montana64]

as far as thickness, i could probably sandwich 4 inches of wood together

Ted

 

[RA_pierce]

as far as thickness, i could probably sandwich 4 inches of wood together

Ted

Those are huge.
I have some smaller ones, they are maybe 1.5cm in diameter and I've got six. They can easily hold up a metal folding chair (if balanced properly).

I have a hard drive I took apart but I can't get one of the magnets out.

And the platters do make good first surface mirrors.

 

[pullbangdead]

^The platters also sometimes have an aluminum bushing between them as a spacer, and that piece of aluminum is often a very good resonator.  Find a hard floor somewhere, like the industrial cement-with-tile floors, and throw the things straight down.  They can bounce VERY well, and sing like a tuning fork.  At least the ones I've had before were simultaneously the best and worst sounds I've heard, quite a high frequency.  

And those are some BIG magnets, geeze, I don't know that I would want tot play with those.




*And just in case any of you haven't thought about this when getting these magnets, DON'T PUT THEM ANYWHERE NEAR YOUR COMPUTER. An idiot friend of mine wiped his hard drive because he didn't think about the possibility that this massive magnet next to his desktop computer might mess with the magnetic fields in his computer. I'm sure most of the people here have thought about this and know not to do this, but you never really know.

 

[Xplorer877]

Yeah the ones in the picture are 3/4 inch thick and 1 1/2 across and the are grade 50! ;D I learned quickly they are not toys you can play with. If you want ones to play around with don't go over 3/4 inch cubes. I think when I bought these they were $15 each. (So worth it!!! LOL)

 

[LRMNmeyer]

I got some pretty strong magnets from the PHR-803T sled. I lost them though. :'(

 

[Jimmymcjimthejim]

I got a sphere that has a 3/4'' diameter, cylinder with 3/4'' dia and height, and cube that's 3/4'' long. Once the cube and the cylinder slammed into each other on the skin in between my thumb and my index finger. Not fun.

 

[Xplorer877]

Yeah magnets from DVD dives are weird. They are magnetized like this I think.
  ___________
/__ __/_____/ l
l   N    l    S    l l
l_____l_____ l/l
l   S    l    N    l l
l_____l_____ l/

Each side is like 4 smaller magnets put together.

 

[artix]

Here is mine. It is a grade N42 1" x1" x1" cube. This one can hold 88 pounds!
I've had it for a while and I've gotten it all smashed up! The triple plating (Nickel, Copper and another layer of Nickel) has been chipped off in some places! :'(

I just took some photos of it and here they are. [smiley=smiley_down.gif]

 

[rocketparrotlet]

I have four 1/4"x1/2"x1" magnets (two N50, two N40), two 1/2" spheres, and a few little ones from random stuff like the PHR-803T sled. I've given myself some pretty good blood blisters from those things! They are nickel coated and have gotten pretty chipped up. I never knew that hard drives had rare earth magnets in them! That's really awesome. I'm gonna have to go find some hard drives.

-Mark