Can magnets wipe hard drive?
Can magnets damage or wipe a hard-drive? I mean, the normal magnets that we can buy at anywhere, not the small ones, but the very big ones?
No, regular magnets won't wipe hard drive data, no many how big they are.
Every hard disk drive actually contains two powerful neodymium-iron-boron magnets that control the movements of the read/write heads. Yet the data on the platters remain unaffected. It will take a very, very powerful magnet to affect the data inside the hard disk drive.
And how powerful should be enough?
Super user contributor hotei gave us the answer:
What you need to harm a HDD is a magnetic field (not a permanent magnet) so strong that it takes 5 minutes of 120 volt current to charge the capacitor that discharges through a coil in less than a millisecond to create the magnetic field to wipe the drive.
So even if you're trying this, you're not harming the platters.
But a Degausser (a machine made for degaussing, the process of decreasing or eliminating a remnant magnetic field), on the other hand is able to wipe data clean permanently beyond recovery. And companies owned such machines would like to provide data sanitizations more then sell them, because they're so expensive for home users.
So play with the magnets around the computer is OK, no need to worry about data losing, since the hard drive itself has magnets built inside, why a magnet outside will affect data.