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QUESTION: Who would have a very powerful A/C magnet? I can't seem to reformat the hard drive of a computer I hope to recycle and I don't want to go the hammer method. In the past haven't been able to break into the casing of a hard drive.

Also what other types of electric magnets are there?

ANSWER: Well, the ignition coil of a car would probably fit the bill. So would most motor coils hooked up to wall current. There are many designs of electromagnet, but in this case you might be best served by a powerful permanent magnet with enough time/proximity to make the erasure stick.

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QUESTION: Since the data would be pretty well corrupt that I could no longer run the OS how could I be sure the destruction is complete? Also how is magnetic measured for strength?

ANSWER: If you want the computer to function, don't destroy the hard drive.  Just erase everything you don't want out there and fill/erase large data files to the hard drive.  Basically, overwrite where things were written.  That should be good enough, it's not like the NSA is going to send your hard drive to some special laboratory to recover the old data.

Magnet strength is measured in Tesla.  There are several ways in which it is measured, generally with something like a Hall effect probe.

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QUESTION: No I want the hard drive completely destroyed. The disc drives and internet aren't responsive so I can reformat with software disc, and I can't download the right low-level reformat software. I want it to be completely blank. How much magnetism will do that?

How much will depend on how much magnetic shielding the drive has built into it and the details of the drive's physical makeup.  If it's shielded, you might not be able to.  You'd have to remove the shielding.  Here are some details by people who've actually approached this systematically:


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Dr. Stephen O. Nelson


I can answer most basic physics questions, physics questions about science fiction and everyday observations of physics, etc. I'm also usually good for science fair advice (I'm the regional science fair director). I do not answer homework problems. I will occasionally point out where a homework solution went wrong, though. I'm usually good at explaining odd observations that seem counterintuitive, energy science, nuclear physics, nuclear astrophysics, and alternative theories of physics are my specialties.


I was a physics professor at the University of Texas of the Permian Basin, research in nuclear technology and nuclear astrophysics. My travelling science show saw over 20,000 students of all ages. I taught physics, nuclear chemistry, radiation safety, vacuum technology, and answer tons of questions as I tour schools encouraging students to consider careers in science. I moved on to a non-academic job with more research just recently.

Ph. D. from Duke University in physics, research in nuclear astrophysics reactions, gamma-ray astronomy technology, and advanced nuclear reactors.

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