What is this Huge Magnet for?

[woodgate]

I bought this at a garage sale for $5. It literally weighs about 40-50 lbs. The bottom is not magnetic so I'm guessing it is lined with lead or something (also adding to the weight). The whole case seems to be stainless steel, and is seamless. The top is a super strong magnet! The guy said he had it in his boat to hold his keys, but what is it really?

There is a tag on the back that is totally illegible, and the only numbers are
78160 SAN1 944

 

[Erampu]

It's a key holder for marine use...

 

[klaus]

It looks like it is to remove the security tags from clothes at a retail store. It would be built into the top of the sales counter.

 

[GRX]

Lead does not block magnetic fields far as I know. The retail store idea sounds likely. So what are your plans for it?

 

[Suzie68]

It's a key holder for marine use...

Now that's funny!

 

[woodgate]

Is it actually a marine key holder!? And if lead doesn't stop magnetism how the heck is SUPER strong on the top and basically has no magnetism on the bottom of it? Does any material block magnetism?

 

[neophyte]

Is it actually a marine key holder!? And if lead doesn't stop magnetism how the heck is SUPER strong on the top and basically has no magnetism on the bottom of it? Does any material block magnetism?

If used right I believe a thin shell of highly magnetic iron can block magnetic waves or at least redirect them. I'm not certain how the iron it would need to be positioned around the magnet to properly work though. There's a Wikipedia page that mentions magnetic shielding. http://en.wikipedia.org/wiki/Electromagnetic_shielding

 

[gorilla]

Their is a material called Mu metal (not sure of spelling) that is used to block magnetic fields. It looks somewhat like lead and is quite heavy and expensive. I think that you have a magnet that was used to direct an electron beam in some kind of scientific measuring device.

 

[GRX]

Blocking magnetism - interesting topic for discussion. Yeah, I think neophyte hit it. Someone more knowledgeable than me can surely explain it better. From what I understand a ferrous material (contains Iron) is used to re-direct magnetic fields around objects, or nullifying them. Also, counter acting (opposite polarity) magnetic fields are created with electricity. This is how our computers work without internal components interfering with each other.

>edit:
You are right gorilla. Your post about Mu metal got me thinking so I did a search. This page explains things pretty well.

>> http://www.newton.dep.anl.gov/askasci/phy99/phy99x89.htm

 

[pendragon1998]

I keep super magnets out of hard drives for use in the garage and occasionally for other things. They seem to have a magnetic side and a non magnetic side, so something is blocking the magnetism.

Edit...well dang, you made me look it up!

Edit 2...GRX out-googled me! lolz

 

[GRX]

^^ lol ... funny we arrived at the same page pendragon. The rare earth magnets from hard drives are made from neodymium. Not sure why they are so directional. Perhaps the steel backing. More Googling required. They can be fun. I have a whole stack of old drives I am about to open with the grinder actually.

 

[neophyte]

Mu-metal is used to back the magnets in hard discs to keep the magnetic field away from the disc. Or so the Wikipedia page says. http://en.wikipedia.org/wiki/Mu-Metal

 

[MikeYC]

It's a Docking plate for a hatch cover off a NUKE sub. Magnet is very powerful and usually takes several to remove from the deck. Used to hold SDV chambers on deck.

 

[pop pop]

Looks like an access cover for a nuclear reactor. Probably radiated. Lined with unobtanium so it isn't magnetic on one side. Might be radioactive though.

 

[GRX]

Unobtainium. Would love some for my shop but can never seem to get hold of any.

 

[Professur]

I have a whole stack of old drives I am about to open with the grinder actually.

I've got a ton of these magnets. A grinder wouldn't be my first choice .. but you'll figure that out quick enough on your own. For taking the backing off them ... I have trashed several trying to use a simple heat gun to loosen the glue. Those magnets are very temp sensitive and temp fragile. The heat gun didn't top 400f, but those magnets are powerless now.

 

[Bob C]

Unobtainium

That magnetic?

 

[iajonesy]

We use that same type of magnet to remove steel material from incoming grain trucks and trains as the grain passes under the magnets. You'd be surprised at how many pliers and screwdrivers,nails, screws,and other **** ends up on the magnets. Never any good tools,though,because most farmers buy cheap **** to use in the fields.

Mike

 

[NUTTSGT]

That magnetic?

Only on one side.

 

[Jagmandave]

Yeah, we had those magnets in our pneumatic conveying tubes, they were so powerful they'd pull the iron out of the flour.....as in iron enrichment, not nuts and bolts.

 

[laser3kw]

HUGE refrigerators

 

[GRX]

I've got a ton of these magnets. A grinder wouldn't be my first choice .. but you'll figure that out quick enough on your own. For taking the backing off them ... I have trashed several trying to use a simple heat gun to loosen the glue. Those magnets are very temp sensitive and temp fragile. The heat gun didn't top 400f, but those magnets are powerless now.

Thanks, I know what you mean. Already have a few HDD magnets on the side of my toolbox. You can practically hang a bench vise on them. The grinder is just to remove the swedged rivets on the outer casing. Found an old 5.25" form factor Quantum Bigfoot (remember those?) in a box of my late father's PC gear. Should be interesting to see what the guts look like compared to the newer drives.

 

[premierplayer]

key holder? wonder how that worked out?

most keys I've encountered are a brass alloy of some type

 

[Albiemanmike]

Unobtainium is completely unobtainable.................................

 

[niget2002]

Unobtainium is completely unobtainable.................................

Only to the uninformed...

As far as a use for the magnet... I don't know what it was for, but I'd use it on a metal bench to hold parts still instead of clamps

 

[Bob C]

Unobtainium is completely unobtainable.................................

Only if you don't have a powerful magnet!

 

[koditten]

key holder? wonder how that worked out?

most keys I've encountered are a brass alloy of some type

The key ring's not.

 

[woodgate]

Man I can't tell whose messing with me or not! I guess karma is getting me back for telling my students to use "striped spray paint" today. (I'm a shop teacher)

 

[Vegaman_Dan]

The real question isn't, "What is it?" but more importantly, "Is it for sale?"

 

[ZRX61]

Make sure it ain't one of these:

http://www.kjmagnetics.com/proddetail.asp?prod=BZX0ZX0Y0-N52

 

[Zelatore]

Make sure it ain't one of these:

http://www.kjmagnetics.com/proddetail.asp?prod=BZX0ZX0Y0-N52

"we always use a three man crew when handling these magnets"
Ok, I get why - something with 1200 lbs of pull could certainly be dangerous, but how the heck do you even get three guys on the thing? It's small enough to fit in your hand. Seriously, I don't even know HOW you handle something like that. Seems like it would be near impossible not to get something stuck to it / it stuck to something such that you just weren't going to separate them.

 

[woodgate]

The real question isn't, "What is it?" but more importantly, "Is it for sale?"

Everything I own is for sale!

 

[bmw57isetta]

If you're tearing old hard drives apart to get those rare earth magnets, put the drive or component that holds the magnet(s) in the freezer for 30-45 minutes. They'll pop right off with the flick of a flat blade screwdriver or case cutter blade. That glue doesn't like the cold. Done it many times. No power loss either. Great little magnets to have around the shop for sure.

 

[Mr_fixit]

Unobtainium is completely unobtainable.................................

Yes, And Iceland is made of ice, right.

 

[Derrickwade]

We use that same type of magnet to remove steel material from incoming grain trucks and trains as the grain passes under the magnets. You'd be surprised at how many pliers and screwdrivers,nails, screws,and other **** ends up on the magnets. Never any good tools,though,because most farmers buy cheap **** to use in the fields.

Mike

I agree with mike. I'm a flour miller, so I see these magnets in the wheat cleaning and conveying .

Yeah, we had those magnets in our pneumatic conveying tubes, they were so powerful they'd pull the iron out of the flour.....as in iron enrichment, not nuts and bolts.

Where do you work?

 

[Professur]

Thanks, I know what you mean. Already have a few HDD magnets on the side of my toolbox. You can practically hang a bench vise on them. The grinder is just to remove the swedged rivets on the outer casing. Found an old 5.25" form factor Quantum Bigfoot (remember those?) in a box of my late father's PC gear. Should be interesting to see what the guts look like compared to the newer drives.

I remember them well and fondly. I was a road tech when Compaq sent them out ... talk about job security. Those things went south faster than a pensioner at the sight of snow.

If you're tearing old hard drives apart to get those rare earth magnets, put the drive or component that holds the magnet(s) in the freezer for 30-45 minutes. They'll pop right off with the flick of a flat blade screwdriver or case cutter blade. That glue doesn't like the cold. Done it many times. No power loss either. Great little magnets to have around the shop for sure.

That little trick is about to get tried.

 

[GRX]

Unobtainium .... that really nifty tungsten-titanium matrix with anti-gravitational properties, that when combined with gravity blocking Cavorite, is indispensable for Anti-Newtonian propulsion systems.

 

[rburke65]

Target just had Unobtainium on sale last week, although I did miss the sale....damn!

 

[woodgate]

Ok when i said i didn't know who was messing with me...I did at least realize "unobtanium" was a joke. I just didn't know how 10 different people had 20 different uses for the same magnet. I guess they are just used all over the place?

Also "unobtanium" gives me an idea to start a new thread for people to give me ideas to mess with my students....blinker fluid, striped spray paint, left handed screw drivers etc etc. I'll start it soon that'd be funny!

 

[woodgate]

What would I title a thread where people donate such ideas, is there even a name for those? ex. muffle bearings etc.