How strong of a magnet would be needed to mess up this hardware?

hard-drive laptop wipe magnet galaxy-s3

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You have nothing to fear. There is no magnetic storage in your phone, so that one is easy.

For hard drives, or any magnetic thing, the property that is important here is called coercivity, which is the resistance of something magnetic to changes in its magnetism. That is, how strong of a magnet do you need to overcome the coercivity of the hard drive?

For modern hard drives, even powerful neodymium magnets are not enough to demagnetize. The same is not true for low coercivity things like credit cards and magnetic tapes. You're much more likely to physically damage the drive by bending the heads by attracting them with a powerful magnet than you are to demagnetize the platters. And that's with rare earth magnets.

The weak magnets that come with white boards or that you stick on your refrigerator? About as worrisome as a cloudy day.

5,840

whatwhatwhat

Updated on September 18, 2022

Comments

whatwhatwhat almost 2 years

I just bought a magnetic dry erase board that also came with 2 small magnets. I intend to carry these items everyday in my backpack alongside my laptops and my phone. Some days, I will have my Lenovo Yoga 2 Pro in there, some days my Alienware M17x R3, and otherwise just my Galaxy S3 phone in a small pocket.

Do I have anything to fear in regards to damaging the hard drives on these devices? I'm not sure if the magnetic strength of a dry erase board is anything to fear...
- fixer1234 almost 8 years
  
  There isn't a universal "dry erase" magnet. The biggest threat will be from something small and hard pressing against one of your devices and scratching or cracking it. It's hard to imagine a magnet of that type causing any damage due to magnetism, even if it's in contact with the device. If you have any kind of padding separating the magnets from the devices, there won't even be a significant magnetic field near the devices.
- whatwhatwhat almost 8 years
  
  There is not, but I wanted to give everyone a general sense of how strong a magnet we were talking about. Clearly, everyone can now put away the thought in their minds of the magnet used in Breaking Bad to destroy police evidence through a thick wall.
- Boris the Spider almost 8 years
  
  Wouldn't worry about the drives. Magnets + screen = not good...
- CodesInChaos almost 8 years
  
  @BoristheSpider How so? With CRTs a strong magnet might distort the image, but even there I wouldn't expect permanent damage.
- Cedric Reichenbach almost 8 years
  
  The Yoga 2 Pro doesn't have a hard drive, but a flash-based SSD (at least mine). Those are not sensible to magnets.
- Boris the Spider almost 8 years
  
  @CodesInChaos I phrased that very badly tbh; I was more thinking about small metal pointy corner + large flexible ultrabook is only ever going to end in tears...