# Neodymium (rare earth) magnet safety



## blacksmithden (Dec 30, 2014)

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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## road (Dec 30, 2014)

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 !


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## ogberi (Dec 30, 2014)

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.


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## road (Dec 30, 2014)

They burn  ?   

Please tell me how you know dis  huh ? 

:roflmao:


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## Eddyde (Dec 30, 2014)

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.


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## ogberi (Dec 30, 2014)

road said:


> 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.


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## arvidj (Dec 30, 2014)

Eddyde said:


> Don't drink and mag.


 :rofl:

With New Years right around the corner I am sure patrols will be providing enhanced enforcement to ensure our safety.


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## ogberi (Dec 30, 2014)

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*


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## wlburton (Dec 30, 2014)

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


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## jim18655 (Dec 30, 2014)

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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## Shadowdog500 (Dec 30, 2014)

Here is a magnet safety video that shows why it squeezes harder the more it squashes your hand. That is followed up by a graphic video of a hand getting squashed.  http://youtu.be/0t8yDnyOaQ8

chris


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## mattthemuppet2 (Dec 30, 2014)

yikes, I don't think I'd want to mess around with the larger sizes, although for some tasks I could do with bigger than the usual rice grain ones.

I did foolishly try drilling through one once, from a hard drive. I wanted to mount something non-ferrous to it with a screw. Drilling took an age to get anywhere and then as it broke through there was bright flash of light and smoke, plus 2 pieces of magnet. Ok, not doing that again!


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## Ebel440 (Jan 1, 2015)

I was just reading this thread and it made me wonder how they would warehouse the larger magnets.  Anyone know how it's done? Are they shipped in big boxes to keep them away from any metal?


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## arvidj (Jan 1, 2015)

Having read this thread I was sure I could handle magnets without endangering myself or others.

How hard can this be. The other day I received several Spillmaster containers ... http://www.use-enco.com/CGI/INSRIT?PMAKA=891-5999 ... and had put various cutting oils in them. I was happy with their stability ... they did not tip over ... but they seemed to be a little light on weight and did not stay where they were put. I thought about putting some heavy metal object in them for ballast but then thought "why not a magnet?".

With confidence ... after all I had read this thread ... I ordered a set of 1.5 inch diameter, 1/16th inch thick magnets. When they arrived I opened the package and went into the shop. I pried one of the magnets off the stack, unscrewed the lid, dropped the magnet into the container and screwed the lid back on. A quick test drive on the end of the lathe compound suggested we were on the right track but a second magnet on top of the first one would increase the holding ability and we would be perfect.

"This is really simple and working out just like I planned". Note that this is often the phrase uttered just before the wheels come off. I pried another magnet off the stack, unscrewed the lid and started to drop the second magnet into the container. In an instant the second magnet slipped out of my fingers and joined the other magnet at the bottom of the container.

Luckily my fingers were not in the way.

Unlucky the cutting oil in the container between the two magnets was in the way. A miniature tsunami occurred inside the container as the inch tall column of cutting oil that had been between the two 1.5 inch diameter magnets was instantly expelled and found a new home on the shop floor.


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## JimDawson (Jan 1, 2015)

You owe me a new keyboard, I just spit coffee all over mine.  :roflmao:


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## atunguyd (Jan 1, 2015)

Small ones have caused deaths too. There are reports of children swallowing then and in one case the two magnets caused their digestive tract to find in half and ruptured where the magnets pinched 

Sent from my GT-I9505 using Tapatalk


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## stupoty (Jan 1, 2015)

atunguyd said:


> Small ones have caused deaths too. There are reports of children swallowing then and in one case the two magnets caused their digestive tract to find in half and ruptured where the magnets pinched
> 
> Sent from my GT-I9505 using Tapatalk



Yeah i saw recently that "Buckyballs" had been banned as they kept falling into the hands of kids that ate them, opps.

Stuart


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## Andre (Jan 1, 2015)

stupoty said:


> Yeah i saw recently that "Buckyballs" had been banned as they kept falling into the hands of kids that ate them, opps.
> 
> Stuart



I have a set of Neocube magnets, very fun to play with. Interesting how magnet toys of similar types got away with it, only buckeyballs were banned to my knowledge.


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## stupoty (Jan 4, 2015)

Andre said:


> I have a set of Neocube magnets, very fun to play with. Interesting how magnet toys of similar types got away with it, only buckeyballs were banned to my knowledge.



I think they were/are the best know brand, maybe they are packaged in a more toy looking way, humm.

on a side note if you need a gigle you nead to search on you tube for

"worlds strongest red neck with the worlds most powerfull magnets"

quite funny, hope he still has all hos fingures 

Stuart


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## george wilson (Jan 6, 2015)

Since these magnets are made from the by products of nuclear reactors(I think),I wonder if they have some degree of radio activity about them?

Also,these magnets sound like a great way to ruin your cell phone,watch,or other valuable objects that they get too close to.


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## stupoty (Jan 6, 2015)

george wilson said:


> Since these magnets are made from the by products of nuclear reactors(I think),I wonder if they have some degree of radio activity about them?
> 
> Also,these magnets sound like a great way to ruin your cell phone,watch,or other valuable objects that they get too close to.



You may be mixing it up with the fact that they can release thorium gas when minning them, although this is a byproduct of almost all digging into the ground.  I cold be wrong though so somone more knolegable may need to correct me hear.

Don't forget the radio active surface plates  all that granite and all.

I am ammazed that i havnt managed to wipe any media or damage anything with them yet but I do use only little ones for pinning notes to metal stuff so maybe thats been helping.

Stuart


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## John Hasler (Jan 6, 2015)

george wilson said:


> Since these magnets are made from the by products of nuclear reactors(I think),I wonder if they have some degree of radio activity about them?
> 
> Also,these magnets sound like a great way to ruin your cell phone,watch,or other valuable objects that they get too close to.



There is nothing radioactive in rare-earth magnets and no products of nuclear reactors are used to make them.

Strong magnetic fields can damage mechanical watches but these magnets cannot harm your cellphone.


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## John Hasler (Jan 6, 2015)

stupoty said:


> You may be mixing it up with the fact that they can release thorium gas when minning them, although this is a byproduct of almost all digging into the ground.
> 
> Stuart



You're thinking of radium gas.  Thorium is a faintly radioactive metal.  There are small amounts of it (as well as small amounts of uranium) in rare-earth mine tailings.  The amounts are far too small to be dangerous (both elements occur naturally at similar levels) but of course people are paranoid about radioactivity.


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## stupoty (Jan 6, 2015)

John Hasler said:


> You're thinking of radium gas.  Thorium is a faintly radioactive metal.  There are small amounts of it (as well as small amounts of uranium) in rare-earth mine tailings.  The amounts are far too small to be dangerous (both elements occur naturally at similar levels) but of course people are paranoid about radioactivity.




Ow yeah, thanks for the FYI , one day i will use the correct words but untill then it's always good to double check 

i know you can run a geiger counter over a crt screen and the reading should go up as the static charge attracts the radium.  We have evolved around granite and radium i think thats what helps. (Not all radiation is the same and all that)

i did take my first omega watch back to the shop and changed it stating it was too radio active for me, seriously it glowed visibly when in a lit enviroment and a friend of mine whos a physicist   she told me their way way over the leagal limit for a radio active source that you can have in an educational establishment.

gota feal for all the ww2 fly boys with eye problems and the ladies who painted it on.

Stuart


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## blacksmithden (Jan 8, 2015)

Ebel440 said:


> I was just reading this thread and it made me wonder how they would warehouse the larger magnets.  Anyone know how it's done? Are they shipped in big boxes to keep them away from any metal?



The ones I've bought have come with heavy gauge sheet metal strips around them. It really cuts the power of the magnetic field. There's actually a youtube video that was made buy a guy who ordered one of those giant 2" x 6" ones. If I recall correctly, it came in a fairly large box, with a lot of styrofoam to keep it in the middle, and had sheet metal on the top and bottom to cut down on the field strength.

I made a 4 ft long magnetic pickup tool out of one of the 1" x 1" ones I had. The shaft is a fiberglass rod that you'd mount a chimney cleaning brush on, and the part that holds/encases the magnet is a piece of plastic that I machined. In order to keep things from getting unexpectedly exciting REAL quick (as arvidj found out the hard way.  ), I made up a couple of sheet metal bracket type things to put on the end when not in use. Even then, I cut a small piece of 1/8" plate and epoxied that onto one of the brackets to cut the power down even more.  By making them in 2 pieces, it's easier to take them off just due to  the fact that there's a limitation of how hard the magnet grabs them due  to their smaller mass. I always put the one that doesn't have the  little block on first.Even with these little things, you have to be careful you don't get pinched when putting them on.

In hind sight, I've ordered some 1/2" by 1" magnets for my metal detecting digging tools for safety sake. These 1" x 1" ones are just too powerful for what I had in mind. The last thing I need it having the one on my shovel finding the one on my hand digger with my finger in the middle....all while out in the middle of nowhere.


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## wlburton (Jan 8, 2015)

My 2" X 2" cylindrical magnets also came packed in styrofoam with sheet steel lining the box.

Bill


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