de-magnetizer?

[cuslog]

Turning some 1.375" round bar - place I bought it from used a big abrasive cut-off wheel to cut it - now its rather strongly magnetized. Turning it on the lathe, its quite annoying to have chips come back and stick to it.
Anyone got a good method to de-magnetize (without buying a de-magnetizer) ?

 

[YYCHM]

Beat on it with a BFH

 

[PeterT]

Never done it myself, but its on the internet so must be true lol

 

[YYCHM]

DIY Tool Demagnetizer

A few days ago, I commented in another thread about using a soldering gun for demagnetizing tools, parts, etc. For a long time, I have used 10AWG copper wire for making my own soldering tips. At one point, I reshaped one of the tips into a circle and it worked very well for demagnetizing screw...

www.hobby-machinist.com

 

[cuslog]

Never done it myself, but its on the internet so must be true lol

I didn't know that heat would de-magnetize and it wouldn't return after cooling. But buying a de-magnetizer off Amazon would be cheaper (I think).

 

[cuslog]

DIY Tool Demagnetizer

A few days ago, I commented in another thread about using a soldering gun for demagnetizing tools, parts, etc. For a long time, I have used 10AWG copper wire for making my own soldering tips. At one point, I reshaped one of the tips into a circle and it worked very well for demagnetizing screw...

www.hobby-machinist.com

Thanks Craig, I might just try that (if I strike out at my Son's place later today) - he's been a pro. machinist for 20+ years, he might just have a commercial one he picked up somewhere in his travels.

 

[YYCHM]

I didn't know that heat would de-magnetize and it wouldn't return after cooling. But buying a de-magnetizer off Amazon would be cheaper (I think).

Not so much de-magnetize but becomes non-magnetic. Can be used to check temperature when heat treating.

 

[Chip Maker]

Do you know anyone with an automatic wet surface grinder? Usually the electric mag chucks have a demagnetize function.

 

[Janger]

If you orient a needle to magnetic North and then hammer it repeatedly it will become noticeably magnetic. Try taking your bar and orient it in random directions and hammer it. I’d be interested if this demagnetizes it.

 

[YYCHM]

 

[cuslog]

Huh;;; Thanks, I'll have to try that

 

[RobinHood]

I have a de-magnetizer. Contact me if you want to stop by and use it.

 

[cuslog]

I have a de-magnetizer. Contact me if you want to stop by and use it.

Thanks for the offer - if you were closer, I would.
I have one of those soldering guns, I'll probably try that first.

 

[RobinHood]

Roger.

 

[cuslog]

So, I've ordered a de-magnetizer (Amazon) - seems like I will have a use for one. I tried the soldering gun trick and it does work but on 1.375' round bar its pretty slow.
This is a "new issue for me".
This steel that I've bought (18 ft. of 4150 "modified") is quite strongly magnetic. It will pick up a 3/4" flat wrench and it will stay stuck on the bottom side of the bar. Its a real nuisance on the lathe, swarf jumps back and sticks to it and everything it touches becomes magnetic.
Talked to my Son (Red Seal Machinist) about this - he said he thought it was a by-product of the heat treatment process of this particular steel - said he'd seen it quite a few times. I'd never heard of it (but that doesn't mean anything).

 

[SparWeb]

You can make a demagnetizer. All standard precautions about handling electricity apply.

You take the transformer out of a dead microwave, saw the end off, slide out the secondary coil. At this point you discard the secondary coil - you don't want to play around with the 5kV that comes out of that. Keep and use the power supply board from the microwave - it has the convenient cord, plug, and should have a fuse to keep you safer using this.

What's left is a primary coil sitting in a big "E". Face the 3 legs of the E pointing up. Rest your magnetized object on them. Plug in the transformer for a moment and unplug it. Half the time when you unplug it, your object will be demagnetized. The other half of the time it's become magnetized, so just do it again until the mag field is gone.

Since it can magnetize and demagnetize, you can re-magnetize your screwdrivers with it, if you like.

 

[Thomas]

If you have an A/C welding machine you could try wrapping the lead around a piece of ABS pipe, energize it then pass the shaft through the center.

 

[Metalistico]

We do this to demagnatize pipe before welding it