Is this a de-magnetizer? (what might this be?)

middle.road

middle.road

Granite Stoopid...
H-M Supporter Gold Member
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Saw a similar picture in another thread and dug this out off the shelves. No ID on it anywhere.
If so, how do you use it properly?
I have it resting on my main file server ready to try out :grin::grin big:
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Got one similar to yours, except mine has a flip up plastic dowel that you can place the old style reel tapes on. They are great demagnetizers. Just hold and rotate the tool or what ever on the device for a few seconds and pull it away while holding the push button. Do not run more than 30 seconds at a time. These were made around the 60s to 80s because mag tape was popular. Now a days, must add one more instruction. Before you turn it on, make sure computers, cell phones, tablets, sewing machines, credit card or anything electronic are some distance away. This is where I must respectfully disagree with Holescreek even though I know it was meant in jest. My wife, who once sold sewing machines, told me about this one character. He had dropped some magnets near his wife's brand new embroidery sewing machine. It cost him a grand to get it fixed. and that was one thing the company would not warrant.
 
middle.road said:
Saw a similar picture in another thread and dug this out off the shelves. No ID on it anywhere.
If so, how do you use it properly?
Click to expand...

It's a bulk tape demagnetizer, probably the right size for the old 1/2" tape used as computer storage. So, it'll
eradicate magnetization in a zone about an inch above the platen, just pass your object slowly over the
surface for a few seconds. The object must then be pulled a foot or so away before you
can turn off the demagnetizer (or it may get magnetized).

There's some serious current required, and it's likely to have a thermal cutout, so power-on
time should be as short as possible (if the cutout activates due to overheating, go get
a cup of coffee, because it can't be restarted until it cools).

These (or other designs) of demagnetizer are crucial to get tweezers and cutters into shape
for handling small iron objects, like bits of iron foil for a Mossbauer experiment in a high-pressure
diamond cell. It takes a steady hand and a stereo microscope, too, and we kept
a demagnetizer next to the microscope.

If a steel cutting tool picks up shavings, demagnetizing it is a good idea: the surface finish is better
when the swarf drops away.
 
I have one very similar to the one in the photo I bought from Enco about 10 years ago for $29 from their sale flyer. We also have one like it in the lab at my workplace. The correct use is to hold the tool or part you want to demagnitize over the top of the machine for a few seconds then pull it away while the machine is still running. I've always been told to never let the part touch the top of the demagnetizer, but maybe that was lore from the really old machines that had a split pole top on it.

I use mine for demagnetizing parts after surface grinding and for demagging hand tools. Amazing how often my stainless steel calipers start picking up chips. Not kidding about the credit cards, it'll erase everything on them fast!
 
Holescreek said:
I have one very similar to the one in the photo I bought from Enco about 10 years ago for $29 from their sale flyer. We also have one like it in the lab at my workplace. The correct use is to hold the tool or part you want to demagnitize over the top of the machine for a few seconds then pull it away while the machine is still running. I've always been told to never let the part touch the top of the demagnetizer, but maybe that was lore from the really old machines that had a split pole top on it.

I use mine for demagnetizing parts after surface grinding and for demagging hand tools. Amazing how often my stainless steel calipers start picking up chips. Not kidding about the credit cards, it'll erase everything on them fast!
Click to expand...
Yes, good for after surface grinding! Even better is a mag chuck control that does it automatically, such as a Neutrofier, which reverses the chuck current in stages, each time diminishing the voltage until there is no residual magnetism; I have one on my B&S Micromaster, and use it to demagnetize tools or whatever needs it. The Neutrofier is a fair sized complicated unit, buy there is a modern equivalent, one of which I bought for the 12 X 36 Thompson in the shop that I retired from; I think it came from MSC and was made in China and very compact in size, and worked and still works perfectly after the better part of ten years of use.
Where I apprenticed, they demagnetized partially by simply reversing the knife switch that supplied the DC current from a huge array of selenium rectifiers, then went to a big heavy field coil out of a DC welding machine, plugged into AC current and you simply passed the object through the coil in and out several time to further reduce the residual.
 
Yes they will play havoc with all types of cards, Had my wallet in my pocket and got to close to one. Had to replace all of my cards, entry credentials etc. Was not fun, made sure to stay away from them after that. We had one that was for erasing 12 inch reels of 1 inch mag tape. It was dangerous to things like watches etc. Ok dating my self again.
 
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