Previous in Forum: Hissing Glass   Next in Forum: Compressor Oil and Has Separation and Testing of Oil Flash Temperature After Use
Close
Close
Close
19 comments
Anonymous Poster #1

De-Magnetizing Tools

03/08/2012 8:56 PM

I screwed up guys. I threw a powerful magnet in with my files. Now, of course, all my files are magnetized. The metal shavings accumulate between the teeth rendering the file useless.

Does anyone know how to totally de-magnetize them?

Reply
Interested in this topic? By joining CR4 you can "subscribe" to
this discussion and receive notification when new comments are added.

Comments rated to be Good Answers:

These comments received enough positive ratings to make them "good answers".

Comments rated to be "almost" Good Answers:

Check out these comments that don't yet have enough votes to be "official" good answers and, if you agree with them, rate them!
Guru

Join Date: Oct 2008
Posts: 42290
Good Answers: 1661
#1

Re: de-magnetizing tools.

03/08/2012 9:06 PM

You just need a degaussing coil.

If you had only known about the Gigantic Solar Flare Will Wash Over the Earth This Morning you could have stuck the files in the ground and the Massive Gigantic solar flares would have done it for you.

(That's a lie, but I'm milking this flare thing.)

One more thing, CR4 is not the place to make personal lifestyle confessions. You should have omitted the first sentence of your original post.

I see admin edited this.

Reply Score 1 for Good Answer
Guru
New Zealand - Member - Kiwi Popular Science - Weaponology - New Member Engineering Fields - Power Engineering - New Member Engineering Fields - Electrical Engineering - New Member

Join Date: Sep 2006
Location: Auckland, New Zealand
Posts: 8778
Good Answers: 376
#2

Re: De-Magnetizing Tools

03/08/2012 9:53 PM

Bashing the files repeatedly against a solid object (or each other) will also do a good job of demagnetising them with the added bonus of relieving stress but at the cost of, well your files. Don't forget to wear eye protection.

Alternatively see post #1.

__________________
jack of all trades
Reply
Guru
Hobbies - Musician - Engineering Fields - Chemical Engineering - New Member Engineering Fields - Control Engineering - New Member Engineering Fields - Instrumentation Engineering - New Member

Join Date: Jan 2007
Location: Moses Lake, WA, USA, Thulcandra - The Silent Planet (C.S. Lewis)
Posts: 4216
Good Answers: 194
#3

Re: De-Magnetizing Tools

03/08/2012 11:50 PM

How powerful and what type of magnet was it?

Along with jack of all trades' suggestion of physical shock (i.e. beating the hell out of the files), heating them up before doing so will accelerate the process. However, it may be more advantageous to purchase new files.

__________________
"Reason is not automatic. Those who deny it cannot be conquered by it. Do not count on them. Leave them alone." - Ayn Rand
Reply
Power-User
Engineering Fields - Control Engineering - Newby Member Long Time User Engineering Fields - Instrumentation Engineering - New Member

Join Date: Jun 2006
Posts: 220
Good Answers: 9
#4

Re: De-Magnetizing Tools

03/09/2012 1:45 AM

Temperature is a wonderful demagnetizer also.

Try throwing the items into a hot oven (300 degF) for a period of time. Be careful of any plastic parts though.

Reply
Power-User

Join Date: Apr 2007
Posts: 414
Good Answers: 19
#12
In reply to #4

Re: De-Magnetizing Tools

03/09/2012 11:48 PM

Yes, but depending on the composition of the files, soaking them at an elevated temperature may anneal them and render them useless as well. Good tools should be treated with respect if not with reverence. You should also clean those files as well as you can with a file comb after your attempt at demagnetization. Doing so beforehand may magnetize the file comb.

I recall seeing construction details and instructions for the use of a line-powered degaussing coil in a handyman's guide published in the 1920's. This article recommended silk-covered magnet wire (or double cotton-covered wire if you couldn't afford silk insulation). Another article in the book detailed construction of a battery-powered two-tube radio constructed on a wooden breadboard. Degaussing coils have been around for a long time.

Reply
2
Guru

Join Date: Jul 2007
Posts: 4448
Good Answers: 143
#5

Re: De-Magnetizing Tools

03/09/2012 7:55 AM

There are several ways to do this:

1. Banging the files with a hammer. Hold the file loosely in your hand and strike it with a hardened hammer peen. You want the g's to be as high as possible. Clamping it in a vise or using a soft hammer doesn't do much.

2. Heating them to the Curie temperature. This destroys the long range alignments and demagnetizes them really well. It also makes them softer than you want. and most air-hardening steels can't be rehardened.

3. Putting them in a strong ac magnetic field and slowly decreasing the strength of the field. You can probably rig up something with an ac arc welder that will do a pretty decent job. You could also find an old power transformer, cut open one side of the laminations and run the primary through a variac to keep from blowing the breaker. A little dangerous, but this would be my favorite as it makes lots of heat and sparks.

4. Putting them in a strong dc field and shaking them quickly as you remove them. See if you can find a starter motor repair shop that has a "growler" to detect shorts. It'll do the trick.

5. You needed new files anyway. Throw the old ones away; they're useless for making stuff unless you spend an hour carefully grinding them smooth.

__________________
"Well, I've wrestled with reality for 35 years, Doctor, and I'm happy to state I finally won out over it." Elwood P. Dowd
Reply Good Answer (Score 2)
5
Guru
Hobbies - Fishing - Old Salt Hobbies - CNC - New Member United States - US - Statue of Liberty - New Member

Join Date: Mar 2007
Location: Rosedale, Maryland USA
Posts: 5198
Good Answers: 266
#6

Re: De-Magnetizing Tools

03/09/2012 8:48 AM

They make these to magnetize and demagnetize tools.

This is one that these guys sell.

http://www.harborfreight.com/catalogsearch/result?q=magnetizer

Look in your local hardware store they may have them

__________________
Life is not a journey to the grave with the intention of arriving in a pretty, pristine body but rather to come sliding in sideways, all used up and exclaiming, "Wow, what a ride!"
Reply Good Answer (Score 5)
Guru

Join Date: Oct 2008
Posts: 42290
Good Answers: 1661
#7
In reply to #6

Re: De-Magnetizing Tools

03/09/2012 9:11 AM

A$4.00 USD solution. GA to ya.

Reply
Commentator

Join Date: Apr 2008
Location: Rhode Island, USA
Posts: 56
Good Answers: 5
#8

Re: De-Magnetizing Tools

03/09/2012 1:50 PM

I don't think you'll have much luck with the recommended gadget from post 6.

You need an alternating reduced field which is gradually reduced to demagnitize. It needs to be powerful enough to run the full extent of the BH curve, and then gradually reduce the field, or slowly draw the device away.

An AC solenoid with the plunger removed works. An AC motor with the armature removed and the field core activated works.

The back end of a soldering gun sometimes does it. I use the back end of a tape head demagnitizer, which works really well.

Reply Score 1 for Good Answer
Guru
Hobbies - Fishing - Old Salt Hobbies - CNC - New Member United States - US - Statue of Liberty - New Member

Join Date: Mar 2007
Location: Rosedale, Maryland USA
Posts: 5198
Good Answers: 266
#9
In reply to #8

Re: De-Magnetizing Tools

03/09/2012 3:37 PM

I have used them to demagnetize tools and to magnetize. Sometime it's necessary to make several passes thru the device.

__________________
Life is not a journey to the grave with the intention of arriving in a pretty, pristine body but rather to come sliding in sideways, all used up and exclaiming, "Wow, what a ride!"
Reply
Guru

Join Date: Oct 2008
Posts: 42290
Good Answers: 1661
#10
In reply to #8

Re: De-Magnetizing Tools

03/09/2012 5:52 PM

But think about it. For 4 bucks, it's worth a try.

Reply
Associate

Join Date: Feb 2010
Posts: 29
#11

Re: De-Magnetizing Tools

03/09/2012 11:02 PM

When you're looking at something with as much mass (size) as a file, you will need something that will develop quite a bit of a field.

I would take a power transformer from an old tv set or something big like that and remove the secondary windings from it. Cut them off with wire cutters or a hacksaw. Be careful not to nick any of the primary windings. They should be the innermost windings on the stack of windings. Once you get them off, you should be able to stick the file into the core next to the primary and plug it into the wall.

Reply
Guru
Hobbies - DIY Welding - New Member

Join Date: Sep 2007
Posts: 1601
Good Answers: 57
#13

Re: De-Magnetizing Tools

03/10/2012 6:22 AM

If you mean you magnetized your computer files, forget about it. If you mean your workshop files, get an old solenoid, remove the coil and wire the coil to a variable transformer. You now have a demagnetizer. Run the file through the hole in the coil while slowly decreasing the voltage across it. The magnetization will be gone.

Reply
Commentator

Join Date: Dec 2006
Location: india
Posts: 63
#14

Re: De-Magnetizing Tools

03/10/2012 9:14 AM

Just take cone coil and apply filed for fraction of second and repeat sequence with alternate direction of current with reducing voltage level. it will demagnetize

Reply
Guru

Join Date: May 2006
Location: Placerville, CA (38° 45N, 120° 47'W)
Posts: 5987
Good Answers: 242
#15

Re: De-Magnetizing Tools

03/10/2012 10:32 AM

If you have a large soldering gun (250W or larger is best; NOT a soldering pencil or iron), it makes a fine demagnetizer. Make sure the tip is fastened tightly with clean contacts for maximum current.

Turn the gun on, take a second or two to pass the file lengthwise through the loop of the soldering tip, and keep the gun on until the last part of the file is several inches from the gun. Obviously the more times you do this, the more complete will be the process, but give the tip time to cool down between passes, as the current drops when the tip is hot.

A similar process can be used to magnetize at least small tools: For this, you simply put the tool in the soldering tip, turn it on and immediately off. The polarity and strength of the resulting magnet are totally random, depending on the part of the AC cycle at which you happen to release the switch, so you may have to repeat it...

__________________
Teaching is a great experience, but there is no better teacher than experience.
Reply
Power-User

Join Date: Sep 2011
Posts: 163
Good Answers: 1
#16

Re: De-Magnetizing Tools

03/10/2012 4:31 PM

I would think the easiest thing to do would be to heat them up if they don't have a plastic handle. I believe quenching them in water right away will make sure the steel stayes hardened.

Reply
Guru

Join Date: Jun 2011
Location: Phnom Penh
Posts: 4019
Good Answers: 102
#17

Re: De-Magnetizing Tools

03/11/2012 3:51 AM

Leave them in the transmitter hut of a TV or radio station for a few days.

If this environment will demagnetise a generator exciter then it will demagnetise files equally as well.

That $4 gizmo is intriguing. What is the operating procedure?

__________________
Difficulty is not an obstacle it is merely an attribute.
Reply
Guru

Join Date: Jun 2011
Location: Mossel Bay, SA
Posts: 777
Good Answers: 21
#18

Re: De-Magnetizing Tools

03/12/2012 4:39 AM

Why bother ? Keep them clean them with that same magnet before/ during use....

Reply
Power-User

Join Date: Mar 2011
Location: Ground Zero of the Pompous and self important....Washington DC
Posts: 416
Good Answers: 8
#19

Re: De-Magnetizing Tools

03/12/2012 8:13 AM

Degausing coil is what you need....perfect for this sort of thing, power it up bring it right up to it and gradually move it further away before poweing it off.

You can make your own with the degausing loops from a older CRT type TV....I made one from the degausing loops from a 35" CRT tv that died, a momentary switch good for 120VAC and the old TV power cord. And some electricalt tape.

I twisted the coil into a figure 8 then folded that over to make a loop 1/2 the original size....and wrapped it with electrical tape to hold it that way.

Reply
Reply to Forum Thread 19 comments
Interested in this topic? By joining CR4 you can "subscribe" to
this discussion and receive notification when new comments are added.

Comments rated to be Good Answers:

These comments received enough positive ratings to make them "good answers".

Comments rated to be "almost" Good Answers:

Check out these comments that don't yet have enough votes to be "official" good answers and, if you agree with them, rate them!
Copy to Clipboard

Users who posted comments:

BDThompson (1); bubbapebi (1); DaveR (1); dkwarner (1); Hilton (1); jack of all trades (1); jarunmagnet (1); lyn (3); Mikerho (1); ozzb (2); RoGrrr (1); Smoothy (1); snatr (1); TVP45 (1); Wal (1); welderman (1)

Previous in Forum: Hissing Glass   Next in Forum: Compressor Oil and Has Separation and Testing of Oil Flash Temperature After Use

Advertisement