Rare-earth magnet fragility

BWhitney

Bruce
Corporate Member
This is a 1" Lee Valley rare-earth magnet. This is what happens with a moment of inattention and allowing one loose magnet to collide with another.

Their insert says in part "All of our rare-earth magnets are strong and should be treated with respect.
Their attractive forces can cause loose magnets to unite with such impact that their edges can chip."

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bob vaughan

Bob Vaughan
Senior User
After having some troubles like that, I tried ordering magnets from Apex Magnets in W.Va. Not only were they competitively priced, the quality was better than what I'd found elsewhere. They know magnets and offer a wide variety of sizes.
 

Phil S

Board of Directors, President
Phil Soper
Staff member
Corporate Member
Here is another recommendation for Apex Magnets
 

marinosr

Richard
Senior User
I have also ordered from apex magnets and their selection and quality is very good. All rare earth magnets will be fairly brittle tho.
 

tvrgeek

tvrgeek
User
What does that mean?

The magnets shouldn't be brittle and shatter like glass.
Sorry, but the magnet is made of the material it is made of. You can't change the properties of metals just because you would like to think so. So, go buy cheap Alinco magnets then. Neodymium in brittle. Complain to mother nature.
 

Jeff

Jeff
Corporate Member
BTW it's Alnico, not Alinco. That's an entirely different type of magnet from rare earth magnets.

I was curious about neodymium magnets but I found more information about them and their physical characteristics.

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Alan in Little Washington

Alan Schaffter
Corporate Member
These aren't your typical old horseshoe magnets!! Neodymium magnets start out as solid materials, pulverized into a powder and sintered with heat and pressure or bonded into the desired shape. Sintered Nd2Fe14B tends to be vulnerable to corrosion which can cause serious deterioration, including crumbling of a magnet back into a powder. Many have a thin nickel coating, but that too can deteriorate, quickly in the case of cheap magnets. Magnets that get too near each other can strike each other with enough force to chip and shatter. Flying chips can cause various injuries, especially to eyes.
 

Roy G

Roy
Senior User
I had bought a bunch from Lee Valley, mostly small ones. I use them for closure magnets on small doors for cabinets. I left a stack of them out in the barn and forgot about them. When I saw them much later, they all had rust all over. Still magnetic, but unsightly.

Roy G
 

BWhitney

Bruce
Corporate Member
If you bought them off e-bay, they are so cheap you woudl not notice.
No these are from Lee Valley. I don't have a comparison from theirs to cheap ones as I have always bought Lee Valley.
And not complaining, just reminding users that they are somewhat fragile. I have been using them for years, and as long as they are treated with respect, they seem to hold up fine. Although as Alan and
Roy mentioned, the nickel coating can and does deteriorate.
 

mkepke

Mark
Senior User
You might be able to save it by epoxying it back together. I did that recently for a magnet that's a critical part of one of my routers.

-Mark
 

BWhitney

Bruce
Corporate Member
You might be able to save it by epoxying it back together. I did that recently for a magnet that's a critical part of one of my routers.

-Mark
I probably could (and may just for S & G) but it is just one of several I have in reserve for future possible projects.
 

Oka

Oka
Corporate Member
If you are going to use them for "work"then get magnets that are either cased in stainless or wrapped in some pother way. I have several of these and none eve have shattered. I do have some cheaper ones and they do shatter. In fact may of the Hard disk magnets look likke they are dipped in some kind of chome coating but drop them hard enough they will shatter.
 

tvrgeek

tvrgeek
User
"That's an entirely different type of magnet from rare earth magnets." Exactly but they are not brittle. My point. Pick the material suited for the job.

Buying a brand name is doing nothing but raise your price. They material is the same. I buy backs of 20 or so cheap and stick them all over the place with 3M foam tape. Hold Allen wrenches, extra bit, the extra screw because you will drop one off the ladder etc.
 

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