×
INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS

Log In

Come Join Us!

Are you an
Engineering professional?
Join Eng-Tips Forums!
  • Talk With Other Members
  • Be Notified Of Responses
    To Your Posts
  • Keyword Search
  • One-Click Access To Your
    Favorite Forums
  • Automated Signatures
    On Your Posts
  • Best Of All, It's Free!
  • Students Click Here

*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

Students Click Here

Jobs

Making Permanent Magnets

Making Permanent Magnets

Making Permanent Magnets

(OP)
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.

RE: Making Permanent Magnets

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.

RE: Making Permanent Magnets

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.

RE: Making Permanent Magnets

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

RE: Making Permanent Magnets

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
 

RE: Making Permanent Magnets

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: Eng-Tips.com Forum Policies
Chinese prisoner wins Nobel Peace Prize

RE: Making Permanent Magnets

Stoopid question...

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

- Steve
 

RE: Making Permanent Magnets

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

RE: Making Permanent Magnets

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.

Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

Red Flag Submitted

Thank you for helping keep Eng-Tips Forums free from inappropriate posts.
The Eng-Tips staff will check this out and take appropriate action.

Reply To This Thread

Posting in the Eng-Tips forums is a member-only feature.

Click Here to join Eng-Tips and talk with other members!


Resources