Neodymium (rare earth) magnet safety

blacksmithden

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For those of you who have handled larger neodymium magnets, you already know this, but I thought I'd share it for some who haven't. As for me, today was my first day owning some of these things. The old adage still holds true....pain is the world's best teacher.

Neodymium or rare earth magnets are available everywhere now. They come in various shapes and sizes.....but don't let the size fool you. They are deceptively strong. You may have watched videos or read warnings about the power of these things in various places. A lot of us find that some of the ridiculous warnings out there today are to protect the very weak (both body and mind). I'm here to tell you, pay attention to the ones on these things.

I ordered a few 1" x 1" cylindrical ones for a couple of digging tools I'm making for metal detecting this summer. As soon as I opened the package and tried to pull them apart, I knew that they were not the magnets I'd ripped out of giant speakers as a kid. Hey...I don't really have to worry about these things though, right ? Man....I'm a tough industrial mechanic with 30 years under his belt. My hands are stronger, and just plane tougher than most.....right ?

I was able to take them apart easy enough due to the plastic spacers the company put in between them. While looking them over...about a whole 20 seconds worth of looking them over, old dumb dumb got sloppy.If you were standing 10 feet from me, you probably could have seen the stupid starting to leak out of my ears because I was overflowing with it. I got 2 of them too close together. Sure enough, I got a chunk of skin on one of my fingers pinched in there. It wasn't anything serious, but it did get me bleeding and it hurt like hell. I have every faith in the world that if you put 2 of these things on a counter, 16" inches apart and you got a finger between them as they slammed together, you're going to have a lot of blood, and more than likely a horribly crushed and broken bone. The real problem then is, how do you get them apart to get your finger out ?

Guys...heed the warnings. The ones I bought are about the size of a dozen quarters stacked together. The largest ones I've seen for sale are 2" x 6" disks. That is just insane. The pull force is rated at over half a ton if memory serves...and that's not 2 magnets pulling together....it's one, pulling on iron. I read one place (might have been fiction, but I have no reason not to believe it) that if you get your hand slammed in between 2 bigger magnets, like 2"x2" cubes, it very well can result in the docs having to amputate your hand. There are 2 issues...first is the initial crush damage that's done. If that wasn't bad enough, remember...these things pull harder, the closer they get together. A LOT, LOT, LOT, LOT, LOT HARDER. When your now munched hand is only separating them by half an inch, by the time you get to the hospital, that distance will have been crushed down a lot more. It's the pinch point that keeps on giving. The problem now is, there's no way for the emergency room guys to get them apart. There's no off switch on these things. Anyway...without getting too gruesome, you get the idea.

In closing...if you're handling these things, wear a pair of decent leather gloves, and ALWAYS be aware of where they are if there's 2 of them. The two that got me will interact with each other when they're 16" apart, and they're not that big. That's with one on the floor, and me hovering the other one above it. The distance on a flat surface where they both could easily roll is no doubt even more than that. When I got pinched, they were already touching on one corner, and then snapped together, flat side to flat side. I don't want to think of what would happen if they were 16" apart on a flat surface, my finger or hand was in there, and they started to fly together. Oh...and one last thing. Don't think that your super human reflexes are going to save you. Once they start moving, the acceleration in unbelievable. These are not the old ceramic magnets we played with as kids that we thought were crazy strong....not even close. It's like comparing a Model A Ford to a modern dragster. Please....learn from my pain. :)

Blacksmithden
 
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Yep . been there done that. even the smaller sizes can pinch. I got a few blood blisters from them.

You gotta admit there awesome though.

If you mount them into ferrous metal parts they get even stronger !

I ordered from http://www.kjmagnetics.com/

READ all the warnings !
 
Ditto on safety. I have a bunch of 1"dia, 3/8" thick ones. they are *BRUTAL*.

They chip easily, the nickel plating is razor sharp, and when ignited, burn like crazy.

These are *NOT* toys. Treat them like they WANT to pinch off a chunk of meat.
 
They burn ?

Please tell me how you know dis huh ?

:roflmao:
 
Yep those Neodymium mags are seriously powerful... About 15 years ago, My business partner and I bought a set of them for evaluating potential uses around the shop (aka messing around with). The day they arrived, we had a much fun conducting various experiments. After work, as was standard operiting procedure in those days, we headed out to the bar, taking the largest pair of magnets with us (you can see where this is going), as I recall, they were about 1" diameter and about .5" thick. At the bar we decided to play a trick on the waitress by dropping one of the mags into a pint of Guinness then move it around with the other magnet under the table. It worked well and it got lots of laughs, we even extended the tomfoolery to some of the female patrons... A couple of more pints later, I had the genius idea that I could get the glass to slide directly to my hand by holding the other magnet in said hand. I somehow "reasoned" the weight of the pint would slow it down enough so it wouldn't collide with my hand with much force. I slowly moved my hand towards the glass and once it passed the event horizon, the glass almost instantly slammed into my hand, the magnet shot between my fingers and thorough the glass. Spilled beer, blood and broken glass ensued. Fortunately I wasn't seriously injured but needless to say the girls were not impressed...
Don't drink and mag.
 
They burn ?

Please tell me how you know dis huh ?

:roflmao:

Am I the only one here that takes out my frustrations on things with a torch when they displease me? :rubbinghands:

Actually, i had a small one stuck un-noticed on a piece of steel I was using to prop up a part for brazing.
 
i can see it now.... drop the mag in your pocket, get pulled over.

"Sir, could you exit the vehicle and stand next to it."
"Sure, officer."
*THUNK*
"What was that?! STEP AWAY FROM THE VEHICLE!"
"I can't! I'm stuck to the car with a magnet!"
"STEP AWAY FROM THE CAR, NOW!"
"But I can't, I'm STUCK!"
"TAZER!TAZER!TAZER"
"ggggggggggnnnnnnnrrrrrrrrrrrrr *THUD*
 
The main other warning regarding rare earth magnets is that no one with a pacemaker should go near them--apparently they will cause them to malfunction. We use 2" x 2" cylindrical magnets to burnish dents out of brass musical instruments (using a large steel ball inside the tubing) and treat them with great respect and caution.

Bill Burton
 
There was a video and web site about magnet safety that has since disappeared. I think it was called "magnet nerd." He had pictures of his smashed and missing fingers from two 2" cube magnets. He was careful while using (playing?) them and while he carried one the other jumped about 18" from the floor and smashed his hand. It was a gruesome sight and a warning about forgetting what you're doing and getting hurt.
I know we aren't supposed to link to other sites but I think in the interest of safety this might be allowed:
http://www.geekologie.com/2009/02/guy-loses-finger-to-neodymium.php
This wasn't the same accident but similar.
 
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