Earth Magnets?

[Kroll]

Guys if you needed or looking for earth magnets who would you order them from and how would you go about selecting them?I have a rubber mat on my ways that I want the mat to stay put till I move it out of the way.So I was thinking that magnets would be the best choice for holding mat in place

 

[JimDawson]

Just order by size and pull. https://www.kjmagnetics.com/

 

[Reddinr]

+1 on kjmagnetics. They have been fast and accurate for my past orders.

 

[homebrewed]

If you've got a Home Depot nearby, they have a variety of rare earth (and ferrite) magnets. At least the one near me does. Harbor freight has some rare earth magnets too, but stay away from the unplated ones (they will look dull and brown-to-black in color). Unplated rare earth magnets will corrode when exposed to the elements and leave black smudges on your hands, etc.

Plated rare earth magnets will look shiny, most commonly gold or chrome colored.

I have bought from kjmagnetics and supermagnetman. KJ is good but can be pricey compared to other vendors. They are a good source of info for size vs pull strength.

 

[pontiac428]

I order my neodymium magnets from Amazon. Having them on hand in a few different sizes (with center holes!) has been super useful in my shop for making things and for organizing disassemblies with small parts.

 

[savarin]

I get mine from old hard drives.
Just ask for the drives at computer repair shops and they usually give them to you.

 

[Cobra]

+1 on kjmagnetics. Great selection and fast service.

 

[Winegrower]

Just remember that rare earth magnets are pretty brittle. If they attract each other, or accelerate toward and crash on a ferrous object, they easily chip or shatter. I’m thinking of the way magnets...might not want to slap them right down on the ways.

 

[homebrewed]

In addition to poor corrosion resistance and their brittle nature, neodymium-boron-iron (NdBFe) magnets have a rather low Curie temperature. They will start to become demagnetized if heated above their Curie temp, and won't recover once cooled back down. According to K&J there is some dependence on the geometry of the magnet. In their examples here they show some magnets can have some loss of strength if heated to only 100C. Probably not an issue for the OP's purposes but good to know if you're going to use them in an application where they can get hot.

If high temperature performance is an issue, samarium-cobalt (SmCo), ferrite or alnico magnets are better choices. SmCo is the most powerful in this group and also the most expensive.

 

[Winegrower]

Per homebrewed comments, I run Samarium Cobalt magnets at over 600 degrees F for weeks at a time without loss of strength.