Making Permanent Magnets 1

[gibsoni]

Hi All,

What a wonderful site this is! Thanks for being a great community.

I would like to make a permanent magnet at the end of a piece of 4130 hollow bar about 1/2" OD.

Is it possible to make a reasonable permanent magnet on the end of this tube?

I have no idea of how this would be properly done but my thought was making a hollow electromagnet that fits over my 1/2" and pulsing it on and off repeatedly? Just a thought.


I was not sure where best to post this questions. Please advise if it should be elsewhere.

Kind Regards, Iain.

 

[JStephen]

I have wondered how they make magnets. My thought was to heat the item above the temperature (I forget what it's called) where it loses magnetic properties, then stick it in a strong magnetic field and let it cool or quench it, whatever would work better.

I'm thinking also, that if the magnetic field is aligned with the bar, the whole bar will be a magnet, rather than having a magnet at the end. And if the field is at right angles to the bar, it'll be short-circuited, so to speak, through the extension of the bar, so you'd have a fairly weak magnet.

 

[kingnero]

I've seen a dozen or more years ago McGyver beating a bar, like he was trying to wrap the bar around a solid post (like a whip). He briefly said something that he tried to move (atoms, elektrons, molecules?) to the end of the bar, making it magnetic. He used he bar after some hits to pick up a set of keys that were fallen in a wever well (correct translation?) near the sidewalk.

I'm not saying this is the most efficient way to make a magnet, but I always wanted to try this myself... this just reminded me again.

 

[asimpson]

You cannot magnetise one end of a ferro-mafnetic material. the whole length will be magnetised. A longer tube means lower magnetic strength.

Depends on what you need the magnetism to do.

Traditionally a permanent magnet like Neodynium is adhered to end of non-magnetic bar.


Look at magnetic engineering thread

 

[cloa]

http://www.eng-tips.com/threadminder.cfm?pid=340

 

[IRstuff]

Seems like you're going to a lot of trouble. Why not just cannibalize a hard drive magnet and glue to the end of your bar?

TTFN

FAQ731-376
Chinese prisoner wins Nobel Peace Prize

 

[SomptingGuy]

I used to get my magnets by breaking up old pin-ball machines that appeared on our local land-fill. I was only a kid at the time though.

- Steve

 

[IRstuff]

The nice thing about hard drive magnets is that they are VERY strong, since they're space limited and need as strong a magnet as possible, given the alloted volume. They're actually a little better if you leave their back iron in place, since it's mu-metal, and that tends to increase the strength

TTFN

FAQ731-376
Chinese prisoner wins Nobel Peace Prize

 

[CorBlimeyLimey]

http://www.rare-earth-magnets.com/c-4-magnets.aspx

 

[KENAT]

Just look somewhere like kjmagnetics and they can probably make you something.

Posting guidelines faq731-376

http://eng-tips.com/market.cfm?

(probably not aimed specifically at you)
What is Engineering anyway: faq1088-1484​

 

[SomptingGuy]

Stoopid question...

Are permanent magnets (the rare earth metal ones) created or discovered?

- Steve

 

[CoryPad]

They are specially-created alloys:

http://en.wikipedia.org/wiki/Rare_earth_magnet

http://en.wikipedia.org/wiki/Neodymium_magnet

 

[zzzjim]

Rare earths could be the next Hot commodity like oil & Gold , if we all need electric vehicles !

 

[cloa]

Rare earths already are hot commodities- pity about stupid regulations about Thorium being nuclear waste - otherwise there would a lot more mines in western countries rather the stranglehold that China has.