How many zeros in a Gigaton hammer

Destroying an HDD hard drive and making it permanently unreadable

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Inspired by a Scientific American post entitled How to Destroy a Hard Drive - Permanently In this guide I would like to show you which methods are useful for making an HDD hard drive permanently illegible. Simply brushing a magnet over the external or built-in memory does not help. And even drilling holes in the storage platters can be insufficient. So what helps to destroy hard drives from water and acid to violence and heat to software and vibrations, you can read here. Good luck with scrapping hard drives!

Destroying an HDD hard drive and making it permanently illegible - this is not only possible with overwriting and throwing it down, but above all with hammer, heat and acid.

Why destroy a hard drive and make it permanently unusable?

It doesn't have to be the hard drive from the PC or Mac that you want to sell. If you simply overwrite it and if it is still up-to-date (short running time, large storage space), then it does not have to be sorted out and replaced with a new, unwritten hard drive. If you want to permanently destroy a hard drive and make it illegible, it can also be an HDD from an old computer that you can no longer get to work. Is it then difficult to connect the corresponding, small disk to the current PC or Mac? Then grab the hammer right away! : D

My experiences with the topic

I have often had the problem that I had to delete ancient hard drives (at that time from the external SCSI housing), but didn't have an adapter to address them via USB or Thunderbolt. Since overwriting with zeros was technically not feasible, I wanted to physically destroy it, because you don't really need 20 GB hard drives again. I finally unscrewed it, broke the electronics and broke the individual disks of the hard drive or bent some, because there seem to be different versions made of glass or metal. That's why I found the article linked above on the subject of hard drive destruction so interesting.

500 GB on external SSD: SanDisk Extreme currently at a discount

Why one magnet is not enough

It is not necessarily true that a sufficiently strong magnet that is brought too close to the hard drive can erase it. First you have to unscrew the case to destroy the hard drive in order to remove the protective steel cover. It is only worth using the magnet when the storage disks are free - but only if it is really strong. And not everyone has a super-strong magnet lying around at home and certainly not stuck to the fridge. In addition, there is no 100 percent guarantee (besides reconnecting it to the computer) that the HDD hard drive has really been made illegible down to the last bit.

How to Permanently Destroy an HDD Hard Drive

In the post linked above, many examples are shown that show that even broken glass storage media, scratched aluminum plates and the like can still be read by experts with a lot of time and money. Surely you don't have to worry about it and you just want to keep curious junk collectors from reading out your youthful sins. These are certainly deterred by a pierced or scratched hard disk disk. Let's think the thought through to the end anyway.

So drilling in the metal plate is not bad. Not only is reading more difficult, but the heat that may arise and deformations on the entire disk can also erase the data. If the memory is not made of aluminum (mostly in desktop computers) but of glass (mostly in laptops), then a hammer will help - or simply to let the hard drive (including the case) hit hard. In short: heat and the greatest possible deformation are a good start.

Acid is also said to be a fairly safe way to make the hard drive illegible. I found a suitable thread in a chemistry forum. In it, a user asks how he can dissolve aluminum plates or destroy the surface. In the further description, the impression arises that he wants to destroy a hard disk without writing it directly. The individual answers show which acid (s) can be used for this. (Be careful when trying it out!)

Completely scrap hard drives: that's how it works!

From a purely theoretical point of view, the mixture of all possible measures should ensure that even the best forensic scientist can no longer read the hard drive. So if you don't trust overwriting with 1 and 0 or this is not possible for you, then proceed (in theory) as follows:

  1. Unscrew the housing and scratch the storage disks with the magnet
  2. Crush the plates into pieces with a hammer, drill, etc.
  3. Send to acid bath after heat treatment

If that's not three easy steps to data protection;)

Usable for non-private storage media?

A brief thought aside from the private use of the measures outlined: not only private individuals who want to destroy old and outdated hard drives or make them illegible may be interested in tips and tricks. Computers of authorities, lawyers, doctors, the military and other institutions, administrations, professions, etc. are full of sensitive data, e-mails and documents. Again, it is probably not enough to overwrite the hard disk with 1 and 0 once.

If you have nothing to hide, you have nothing to fear ...

In the last paragraph of the Scientific American article How to Destroy a Hard Drive - Permanently there is also the hint that a completely destroyed hard drive is an indication that something has to be hidden - at least before a US jury. So anyone who just wanted to eliminate his old hard drive, which was no longer compatible with new computers, full of embarrassing youth photos, could be viewed directly as a terrorist. In Germany there is basically the so-called presumption of innocence, which should protect you from something like that.


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Jens has been running the blog since 2012. He appears as Sir Apfelot for his readers and helps them with problems of a technical nature. In his free time he drives electric unicycles, takes photos (preferably with his iPhone, of course), climbs around in the Hessian mountains or hikes with the family. His articles deal with Apple products, news from the world of drones or solutions for current bugs.