How do you destroy an old hard drive?

  • How do you destroy an old hard drive? To be clear, unlike questions Secure hard drive disposal: How to erase confidential information and How can I reliably erase all information on a hard drive? I do not want to erase the data and keep the hard drive, I want to get rid of the hard drive for good. It's old, small, may (or may not) contain personal information, and is not connected to a computer (a step I prefer to avoid). I might as well destroy it because it is easier and more certain that the data is destroyed too.

    Any other advice is also appreciated as an answer. Keep in mind I am looking for an easier and more reliable data-destroying solution than wiping drives.

    Just wanted to add, from both personal experience and warnings of others, that if you dismantle a hard drive you should watch out for how powerful the magnets are. I doubt there is anything to worry about unless you purposely play with the magnets. They are powerful enough that I could not pull them apart with my hands. They could easily pinch you or hurt you badly if they were to slam together.

  • Scott Pack

    Scott Pack Correct answer

    9 years ago

    Physical destruction of a drive is tricky business. There are many companies that deal specifically in the field of data destruction, so if you are doing any kind of mass you may want to at least look at their price list. If you contract, make sure the company is properly bonded/insured, and provides audit trails for each destroyed item. In the worst case scenario that your information does get out, you want the document in hand that says your contractor properly destroyed the item in question. Then, at least, you can transfer the liability.

    When it comes to drive destruction you typically see one of two main fields:

    1. Disk Degaussing
    2. Physical Destruction


    Degaussing used to be the norm, but I am not such a big fan. On the plus side it is fast, you'll normally just dump the disks on a conveyor belt and watch them get fed through the device. The problem is auditability. Since the circuitry is rendered wobbly, you won't be able to do a spot check of the drives and verify that the data is gone. It is possible, with some level of probability unknown to me, that data could still exist on the platters. Retrieving the data would, without question, be difficult, but the fact still remains that you cannot demonstrate the data is actually gone. As such, most companies now will actually be doing physical destruction.

    Physical Destruction

    At the low end, say a small box of drives at a time, you'll have hard drive crushers. They're often pneumatic presses that deform the platters beyond useful recognition. At the risk of supporting a specific product, I have personally used this product from eDR. It works well, and is very cathartic.

    At a larger scale, say dozens or hundreds of disks, you'll find large industrial shredders. They operate just like a paper shredder, but are designed to process much stiffer equipment. The mangled bits of metal that are left over are barely identifiable as hard drives.

    At an even larger scale you can start looking at incinerators that will melt the drives down to unidentifiable lumps of slag. Since most electronics can produce some rather scary fumes and airborne particulates, I would not recommend doing this on you own. No, this is not a good use of your chiminea.

    Manual Dis-assembly

    If you are dealing with one or two drives at a time, then simple dis-assembly might be sufficient. Most drives these days are largely held together with torx screws, and will come apart with varying levels of difficulty. Simply remove the top cover, remove the platters from the central spindle. Taking a pocket knife, nail file, screwdriver, whatever, have fun scoring both surfaces of each platter. Then dispose of the materials appropriately. I cannot speak to how recoverable the data is afterwards, but it is probably sufficient. The biggest thing to keep in mind is that while most desktop hard drive platters are metal, some are glass. The glass ones shatter quite extravagantly.

    You should also take care of removing and destroying the memory chips on the board because of cache memory and (with "hybrid" drives) of NAND chips containing up to 4GB of cached data.
    A good way to do that is to wrap the board in linen or another coarse cloth and hammer it, that should keep broken parts from flying everywhere.

    Additional Considerations

    Before you decide on a destruction method, make sure to identify what kind of data is stored on each device and treat it appropriately. There may be regulatory or legal requirements for information disposal depending on what data is stored on the disk. As an example, see section 8-306 of DoD 5220.22-M.

    For hard drive destruction, DoD 5220.22-M section 8-306 recommends: "Disintegrate, incinerate, pulverize, shred, or melt"

    All that being said, performing a single pass zero wipe is probably sufficient for your purposes. Modern research indicates that modern hard drives are largely immune to the "magnetic memory" problem we used to see on magnetic tape. I would never bother doing anything more on a household drive unless the drive itself was exhibiting failures.

    Wow. Thank you for all of this information. You went above and beyond on this one, covering all bases, but thank you for this. I like how you mention the kind of data and how it matters. I will now have this in mind the next time this matters. EDIT: I would vote you up if I had permission.

    @MatthewDoucette Answer acceptance is worth a bit more than an up-vote, although when you have permission you can indeed do both.

    @Iszi, thanks. I now have permission and have done both! :)

    +1 for dis-assembly; I think this is the most appropriate and clean method for dealing with a single drive.

    @Shadok Good point on the cache and hybrid drives. In the case of RAM, the data generally dissipates fairly quickly (on the order of seconds or minutes, not accounting for targeted cold-boot attack events). I assume the same principle applies, though I don't know. I would also imagine that degaussing would handle those instances. The same auditability problems are likely to still occur, so physical destruction is generally better.

    I was wondering about the effects of degaussing on RAM but I can't find anything on that. Given the price of it and the lack of guarantees brought by degaussing I agree I'd just hammer it the same way. HAMMER EVERYTHING ! ^^

    I saw one of those shredders in action recently. Hard disk in, pellet-size chunks out, all in under 10 seconds. They are monstrously scary.

    @Polynomial: And monstrously awesome! The bigger ones will chew through anything you throw at it. Desks, televisions, Xerox Workcentre sized MFPs.... Scary stuff indeed.

    @ScottPack This one was specifically designed for hard disks, and included a degaussing phase. Obviously at that point it's like dipping the tip of a cruise missile in cyanide, but I guess it's one of those "boys' toys" factors. With the retail price they stated, I think the extra features were warranted!

    If the 'manual disassembly' method is good enough for your application, don't throw out your hard drive parts! That is good, extremely high-quality metal there, there is no reason to let it go to waste. There is an infinity of things you can do with hard drive parts after you take the drives apart. They have some super-slick bearings, a super-flat and shiny platter, a small-yet-powerful motor for the platter, a linear actuator, and really great case that can be used for a number of craft projects. Surely you can do something with it?

    @AJMansfield: Not to mention badass magnets. I've used them in place of hangers for storage bins and one of our auditors used them as bolt-holders when working on her Jeep.

    "Manual disassembly" works even better if, after carefully disassembling each piece of the drive, you make a double-pass check on EACH piece with a Consistency Check Tool (a big hammer will do).

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Content dated before 7/24/2021 11:53 AM