How-to: Thermite hard drive destruction

After the overwhelming response to the Hackit we posted about automated hard drive destruction last fall, we finally decided to test out some thermite hard drive destruction ourselves. This has been done on The Screen Savers but they did not show up close results of the platters. So, aluminum and black iron oxide were procured through eBay, and until it arrived we watched some YouTube videos that showed a lot of fire and no real results. We decided to see what it would take to completely obliterate a drive.

With the amount of personal data stored on your computer, we all understand the importance of destroying the data that is stored on the platters of a hard drive before disposing of it. There are many ways to destroy a hard drive; software, physical disassembly, drills, hammers, magnets/electromagnets, and acid, but none are quite as outrageous and dangerous as thermite. That’s what we’re going to do here today. Follow along for pictures and videos of the results.

A couple different methods of containing the thermite above the hard drive were tried and we quickly found the best way is a clay flower pot with the drip tray for a lid. An Altoids tin was also tried, but it burned up to quickly. Molding a cement container was also attempted. Since thermite is extremely hard to ignite, sparklers that were left over from the 4th of July were used, and offered a very reliable method of ignition.

Our goal was to completely destroy the drive while it was still in the computer case. The theoretical application is to destroy the disk at a moments notice so it won’t fall into the wrong hands. After testing multiple methods, placing about 1 pound of thermite in a clay flower pot and lighting from the drain hole in the bottom yielded the best results. This could easily be placed in the 5.25″ bays above the drive.

A thermite reaction is a process in which the correct mixture of metallic fuels are combined with a metal oxidizer and ignited. Ignition itself requires extremely high temperatures, but once ignited, thermite supplies its own source of oxygen. It can potentially burn underwater when mixed properly. Thermite is usually used to weld railroad ties together.

The most common thermite is “black or blue iron oxide (Fe3O4), produced by oxidizing iron in an oxygen-rich environment under high heat” and Aluminum(Al). Red iron(III) oxide (Fe2O3), commonly known as rust, can also be used. There are many chemicals that can make thermite; the mixtures used to make thermite therefore vary, causing confusing and changing mixture ratios.

Since the oxidation of one substance involves the reduction of another, this type of reaction is often called redox reaction. In the following balanced reaction, 8Al + 3fe3O4 = 4Al2O3 + 9Fe + Heat. The element Al is oxidized, but Fe is reduced. This reaction is also called a displacement reaction because Al displaces Fe in the oxide. Because of the nature of this reaction, the correct ratio of substances is important to ensure the optimum amounts of fuel (aluminum) and oxygen (iron oxide) within the mixture. Thermite is very safe to handle because of the high ignition temperatures required, sparklers were used in this instance, however magnesium ribbon can also be used. We think an electric pyrogen igniter would be a far better choice for ignition, instead of unreliable methods.

There are two important aspects to ensure a successful reaction. Thorough/even mixing and smallest possible powder particle size. If thermite is not adequately mixed, it may be difficult to ignite or maintain the reaction. One problem when mixing thermite is the difference in weight between the aluminum and the iron oxide. This causes them to separate out rendering the thermite useless. The process used here with great success was five minutes in a rock tumbler. Powder particle size is measured with a measurement called mesh. Passing the powder through a mesh will determine the largest particle size, this reaction performs best with the smallest obtainable mesh size. The mesh size for aluminum was 1200 mesh and black iron oxide was 300 mesh.

The total enthalpy or heat content released is -3.677 kJoule per gram of Fe3O4/AL thermite. The ratio of Fe3O4 to aluminum powder by weight is about 3.22 to 1, according to the reaction’s stoichiometry. The reaction photographed was 200 grams of Aluminum and 644 grams of black iron oxide yielding 2368 kJoules of heat. This was more than was required to adequately destroy the hard drive, a smaller amount could have been used, and still destroyed the platters. It would have even been better controlled, or better yet contained within the computer case. What fun is that?

Using thermite to destroy a hard drive is a very violent and destructive process. Great care should be taken as the molten metal can splash and sputter for a long distance.

The reaction begins to sputter.

The thermite has just contacted the hard drive.

Things are really hot now!

Most of the reaction is completed.

The molten thermite, platters and most of the aluminum frame from the hard drive in the bottom of the case.

Above are the molten hard drive platters destroyed with 844 grams of thermite. It takes about this much thermite contained directly above the drive to get the job done, if it is not you will just get a superficial fire.

Over all the destruction of the drive and platters was accomplished in all cases in a matter of seconds. This is by far a guaranteed method of destroying data in a time of need. We’re pretty sure this will prevent most forensic data recovery methods.

Below is a video of Brainiac using thermite to burn cars and trying to stop the reaction with liquid nitrogen.

Here’s the directors cut of the thermite video which contains 4 extra minutes:

Finally, please do not try this.

103 thoughts on “How-to: Thermite hard drive destruction

  1. Heck… Why not just build an incinerator and mount everything inside using environmentally friendly hemp rope… You feel the heat coming you press the button and poof… Computer what computer. Heck you could buld a cluster server in there too… All wireless.. A dummy terminal as a monitor… You could even run a program from the computer to incinerate itself remotely from your telephone. EEE PC… OR whateva.. Please guys leave the thermite for outside..

  2. Wow “bad1deas,” formatting you hard drive and allowing all your recoverable data to deliberately fall into the wrong hands is pretty much the best idea ive ever heard.

    though I think a better idea is if you hear the FBI at your door, just ctl-alt-delete and end the process explorer.exe, when they try to use your computer they won’t be able to click on anything! that’ll show em whos boss

  3. I can imagine how the airplanes made mostly of aluminum would react with twin towers frame of iron, causing an unintentional thermite reaction.

  4. I have some very sensitive data that I must use for my job and, unfortunately, which I must retain for five years after it ceases to be relevant. The data are only for my eyes and a few officials at my workplace. So I took up a particularly gruesome task of researching how to enable a safe, automated self-destruction process.

    I currently have an explosive round above the top shield of the drive. Its detonator is linked to a 12V power connector which is driven by a relay controlled by an LED header. I had to write a small program to prompt for three separate passwords before lighting the “LED” (thankfully it’s easy to test by hooking up the relay to an automotive light).

    Advantages: It can be set off at a moment’s notice from anywhere if necessary, so long as the server is powered.

    Problems: I do not know if the amount of explosive is inadequate, adequate, or wildly overpowered. I do not know if the shielding I mounted above it is sturdy or enclosed enough to direct enough of the blast down into the drive through its lid. I am pretty sure it is probably very illegal almost anywhere. since the server is a server, any inherent security flaw could potentially enable an outsider to read the data anyway, circumventing the physical protection. because the server is off-site, i cannot immediately know if it has been detonated by some other means than myself.

    I had a second thought (probably more elegant) but I didn’t have a clue how to do it right. Maybe some geniuses here could help because I’d prefer it over explosives. I would want two solenoids hooked up to very sharp center-punches. One would be near the center of the platters, above the drive lid and the other would be over the drive lid near the very outside of the platter enclosure. I would need a pair of tubes and a pair of glass tanks for gravity feed into the hole near the center of the lid: hydrochloric acid in one and nitric acid in the other. Once the “fill” and “air” holes had been punched, the acids would somehow gravity feed into the drive. As the platters spin the acids would be both mixed and tossed all over the inside of the enclosure, and as these two acids mix they create a particularly corrosive, stinky liquid that would be ideal for drive destruction. I just wish I could implement that one; too many missing pieces exist, though.

  5. thermite is a finely ground mixture of specific compounds – iron oxide would not have been present by accident – plus, if crashing an aircraft into a skyscraper produces thermite, then i bet i could crash my Sunfire into the grand canyon and at the bottom i would find a BMW. It’s possible right?? The right raw materials are present!

  6. srry dudes but do you know how a harddrive is actualy build its not the platter but kind of paste shit where the little magnet thingy’s are on whipe it of someway and the date is lost forever and can never be restored so do what i do make something to put the voltage of ur system so hai that the harddisk wil turn to fast and lose the paste or shake it real hard belive me it does the trick and i even dit test it with sending the disk to a recovery place so before saying something stupit test it first ow srry for the typeo’s becuase my englis is not that good

  7. How the towers went down was fishy from an engineering stand point esp when. An idiot on Discovery who was not a real structural engineer said it’s impossible for a large building to topple they can only implode on them selves when in the Kobe earth quake some large buildings did exactly what Mr retard said was impossible fall over.
    But back on the subject termite may be showy but why not do something less suspicious such as introduce emery powder inside the drive?
    Or have a large magnetic coils on top of the drive hooked to some big caps charged to lets say 1200V?
    Have the EMP system fire 3 times reversing the polarity each time?

  8. You know it’s well known and mentioned in various articles and programmes about the WTC that it had several vaults, also underneath the towers, and it’s also known there were some shady organisations and spooks that had offices in the WTC (I hear rumsfeld was actually in the WTC at the time of the attack for instance).
    Now it seems obvious that some of those vaults had some stuff in it that they don’t want to get out, and seems quite possible/likely that they took measures for that, measures like the one described here, that is I’m guessing they had in fact thermite in/under the WTC to destroy material that might get in the wrong hands.
    So perhaps the heat observed was actually thermite but not involved in bringing down the place but as a reaction to the building going down and them destroying material (evidence/secret files/illegal-stuff/maybe biological material and whathaveyou).
    Ponder on that one.

  9. Lots of trouble to mix yourself. Most any electric/industrial supply outlet will have a product called “CadWeld” Comes in “Shots” containers about the size of a 35mm film cannister. The commercial version is generally contained in a graphite mold which is placed over the item to be exothermically welded. The reaction can be sparked using a ignition powder or via an igniter similar to that used for model rockets. A small brass disc holds the material inside the mold before the reaction starts, then burns through and allows the molten metal to flow down into the joint. Radio stations and large electrical system designers (such as server farms) use the product when creating a solid ground system.
    To my knowledge “Exothermic Welding” products are not restricted, but it would be a good idea if you actually looked as if you knew what you were doing when you attempt to make the purchase. Most wholesale houses will not sell unless you have a commercial electricians license, but there are plenty of contractors out there who might be convinced that you have a real need for it…or buy them enough beer…

  10. Ok.

    1. People who post comments should read previous comments first.
    2. WTC theories are clearly not related to this topic. Im sure there are forums out there for that. This topic is about hard drive destruction
    3. This ought to cover everything needed in regards to non-physical data destruction of drives
    4. Yes. The chances of someone recovering your data is low, very low if youve digitally destroyed it. However if your dealing with alphabet agencies, do you want to risk it only to find out you get to be the test puppy they implement Scanning transmission electron microscopy on successfully?
    5. Hippies worried about a little AlO and Fe? Fuck off. One burning PC is not a big deal. Go to india and check out the INSANE computer landfills there where the heavy metals are just leaching into the earth. Then come back and talk. Until then, if you want to tell me how to capture all my emissions and recycle and collect each little component and do my bit when im frantically destroying my computers, you clearly arent using your head.
    6.Yes, there are many more easy/safe ways to destroy your data, not necessarily as quick or as easy to setup (setting up depends on preparedness) but this article was clearly NOT meant to be tried at home. If you want to destroy data use magnets to repolarise magnets. And do it multiple times. EMPs in reversing directions (say oh i dont know. 50 times a second) should do the trick REAL quick.

    Bah. See what ignorance has made me do? Ive gone on a rant at 3 in the morning!

    If your going to comment people, for the love of god. KNOW what your talking about and NO! NO! We do NOT want to hear your 9/11 WTC shit.


  11. Go look up some ATF regulations. The legal shitstorm you’ll get into when they do chemical tests and find that you’ve illegally manufactured an incendiary mixture is far worse than whatever horrible crimes you think you’ve been committing on your computers. This is probably the stupidest idea in terms of trying to get yourself out of trouble that I’ve ever seen.

  12. honestly, y’all need to check on some of the things you type before typing them. If you do any research on thermite then you would have known that it is a perfectly legal incendiary mixture to own/manufacture for your own use, so is dynamite and other explosives. I am not saying you won’t get into trouble if you get caught with it, you will because of all this bullshit freedom taking away shit and you will need a good lawyer to keep them from twisting the truth. But there is no law saying you can’t make them, even on the AFT website they have a PDF that states the law that you can own and manufacture any high explosive so long as it is for your own private use and will not be given or sold to anyone else.

    That is besides the point, Thermite isn’t and will never be an explosive, it is a highly energetic reaction that is labeled as an incendiary mixture and would never explode even if you put it in a pipe with the ends closed.

  13. To: sigh and everyone else



    Below are some documents that I have looked up from the ATF website. The very last one is an email from me to the ATF asking if the making of small amounts of explosive for your own use was legal.

    Look at 1b.

    List of explosives

    Not defined as an explosive and neither are the components

    This is a quote from an email I sent to ask them about making small amounts of explosive,

    “You do not need a license to manufacture if you are manufacturing for your own use however there are qualifiers/caveats as explained in our newsletter pertaining to the manufacture of bi-nary explosives. This article that appears in the June 2004 ATF Explosives Industry Newsletter covers the qualifiers/caveats. You can access the article at our website”

    This is the message I sent the ATF

    “I have tried, successfully,
    making my own black powder but I found out that this could be possibly
    illegal so I was doing some research. I was looking at getting a license
    for manufacturing but as I was reading Q&A there was a question saying
    what is a manufacturing license for and the answer was that is was for
    making explosives for selling and the use in businesses. Later it says
    you do not need a manufacturing license for personal use but technically
    I will be making the explosive. I don’t plan to allow any one to use
    these other than me and I do not plan on making any large amounts(no
    more than 50 grams of any substance in a month or so). I also found in
    another Q&A that a person could purchase dynamite for farm/ranch use
    with out a license. I do live on a ranch and there could be the
    possibility that there may be a stump or something removed. I am greatly
    confused right now and need help. I will not continue to do anything
    illegal as there is no reason to break the law. If this is illegal I
    will do my best to get a license so I can continue my experiments.”

    Hope this help, also don’t forget to check state laws.

  14. P.S.

    sorry forgot to add in there, I couldn’t find the original pdf I had found, I know it is still there I just didn’t want to take any longer looking for it.

    This should be enough anyways.

  15. I noticed a huge typo, right under the link for the list of explosives where it says “not define as” it should say

    “thermite is not defined as”

  16. workaround for spewing all this fire and brimstone just to fry a disk platter is: a nice five and half pound sledge, using the wedge end of course, be sure to invert the drive before stiking! Try it => go green…:)MZ

  17. with any combustion there are gases, although they are not inert, they are stored not in a green house but in the ambient airflow, particulate matter is more of a threat to air quality within the danger zone, unless you live in LA or Denver; as a direct product of such combustion-the main threat is the byproduct of any combustable which is H20, being that its not pure and may have traces of formaldehyde, heavy mtls such as lead, white metal and a little arsenic which is everywhere these days, not good! Why spread it around?

  18. Gawd! The number of would-be amateur woodchuck chemists/enviro-wackos here decrying the deplorable emission of mythical vapors here is truly deserving of a facepalm for the whole human race. For the last time, the thermite reaction itself produces no harmful offgassing, be it formaldehyde, lead, arsenic, etc. By the laws of science, you can’t spontaneously generate elements that aren’t part of the reaction. Now, if the entire destruction apparatus was enclosed in an appropriate ceramic crucible and isolated from the rest of the components, the peripheral components (i.e. drive controller PCB) may not even produce significant detrimental byproducts. And who’s to say that even those gasses/particulates won’t be sequestered within the molten metal?

  19. I have to agree with PacoBell, anyone here who believes the thermite creates toxic crap should go back to school… seriously I learned this stuff at 14. No by-products are produced into the air through this. The intense heat however could pose a problem with the metal, but in all honesty, its negligable.

    On the data recovery side, I’ve done some data recovery, I’ve written encryptions, I’ve read up on the history of data recovery/encryption/etc, I’ve put a lot of effort into researching forensics of computers as this was at one point what I wanted to do for a career. So, taking that all into consideration, I know a fair bit about recovery methods ;) First off, formatting or any software methods for that matter are utterly useless, given enough time you could easily get data back, the only encryption that can perfectly secure data is a One Time Pad, however its just dumb to even consider using one (Wikipedia it if you want to know why)… drilling/sawing/smashing a hard drive into tiny peices is as useful as handing a passworded drive to a PC geek. On a 500GB HDD, a square cm of HDD would give you many gigabytes of data… Degaussing is a good method (which someone mentioned), basically destroying the magnetic field via heat or intense magnetic radiation, there is no logical or theoretical method for recovering data in these cases, so a lot of places do this. Finally, the government and “secret” organisations generally prefer total destruction of a hard drive by using similar things to thermite, purely because whilst no theoretical method exists for degaussed data recovery, its possible someone could find a way some day (and then theres those paranoid people who believe the government can do it but won’t admit it). You’ll also need to completely destroy the RAM, as its been proven that data can be recovered from RAM under certain condition (I believe they extracted data from RAM some 50 hours after the PC was powered off).

    At the end of the day, the simple rule of thumb is don’t be a dumbass, stay out of trouble… don’t get caught ;)

  20. i am not sure how well this would work but why not have a container of Acid above HDs . break container when needed to destroy HD. ?????

  21. excellent experiment. several points in response to comments:

    1. aluminum and aluminum oxide are toxic to humans. don’t breathe it. don’t eat it. that said, using thermite to destroy an HD presents less toxic materials into the environment than the process of making the PC and chassis to begin with, so get a grip, get a life, and don’t buy any more computers if you’re so worried about it.

    2. thermite itself is not considered an explosive although it will sputter molten metal in a semi-explosive manner. however, thermite in combination with sulphur, copper and/or magnesium can be used as an explosive. further, the explosive bolts NASA uses for decoupling rocket stages are thermite. further, thermate is explosive, and nano-thermate is highly explosive.

    3. the military and intel dispose of HDs in two ways: strong magnetic fields (strong enough to actually warp the platters) and incinerators. acid might be used too, idk.

    4. of course it was an inside job, see “The Ghost in the Machines: Evidence of Foreknowledge in the WTC Hard Drive Recoveries”

  22. @threepointone dude whoah hold on… you mix a huge block of ice with a sealed fire box or whatever and you get a massive bomb complete with shrapnel.

  23. According to the examples above: Flowerpot (mostly) pwns Thermite. Although I did see a couple of cracked examples, the leakage is generally through the hole in the bottom.

    Perhaps put HDD in a long planter pot (like a window box), to contain the reaction?

  24. apparently you can melt playdough into thermite in the right quantities and make a mouldable thermite block which can be stuck anywhere. like to see someone try it.

  25. Yeah im doing this, I am also going to build a enclosure that prevents anything from getting out once it “self destructs”; I am thinking clay+concrete (probably 2-3 layers of clay panels/tiles with concrete or something else heat resistant holding it together). oh and shred, yeah I have the same tool, its great to do a 35 pass system when you have a week to spare, but these kinds of setups are for 10<15 second guarantee's. now if you don't mind I have to go find my lead lined hat with two layers of tin. (one on the out, one in the in.) ;-)

  26. A powerful heating element incorporated into the drive, or an induction heating coil would heat the platters enough to destroy the magnetic domains within the platters,job done, no destruction of the rest of the room, no outward signs that anything is amiss while the men in suits are invading the room, no chance of being charged with arson or assault with an explosive device, just quiet privacy.Could be worked of a decent lead acid battery within the case rigged to a tilt switch so if the computer is moved or stolen, data is gone.Ram does not hod residual data, without a strobe refresh the data is gone.

  27. As an IT technician, I have to agree on the forensics aspect. This would securely wipe the drive permanently.

    I would point out that the weakness of the software method is that it takes time. I’ve erased a lot of hard drives and it takes anywhere from 20min-2 hours to securely wipe the drive. If at some point a paranoid crackdown does occur, you are simply not going to have that kind of time. If you think your wiping software will do the job, try wiping a drive then using over the counter forensics software to access the data. Unless the drive is overwritten several times the data can still be retrieved. Overwriting an entire drive takes time. Time you may not have.

    An alternative method, if you’re just getting rid of an old drive is to remove the platters and take an angle grinder to them. All the data is stored on the magnetic coating on the disk. Remove the surface and, and there is no realistic means of retrieving the data that I am aware of. The platters themselves are made of aluminum and wouldn’t retain much, if any data from magnetism. (being non-ferrous)

    Further, thermite is not explosive.

    It is also totally legal. There are even some folks trying to use it as an alternative energy source. It is fairly low in pollution values, especially in a controlled burn environment.

  28. SAFETY NOTE TO ABOVE: wear adequate eye and respiratory protection on the angle grinder method. The coating is poisonous if inhaled.

  29. Yeah you realllly dont wanna mess with termite in the US theese days unless you want a visit from a bunch of men in black.. and that will piss off you mom or girlfriend :-)

  30. Made thermite in high school, 10th grade physics. Magnesium wick initiator, iron and aluminum dust from the metal shop, mix the iron with water for a couple of weeks, dry it in the sun for a day and make the girls think you’re a genius. That was 1958. My best and fastest method for protecting data is to use SATA or IDE estension cables to put the drive externally mounted. A hammer in the drawer is pretty quick to reach. Hammers and drawers are leagal, as well as extender cabled. Ugly, but efficient. And you can pop the drive in your pocket (and the hammer if you have a loop on your pants) when you leave the computer. Gateway used to build a laptop with a removable disk. The alphabetters put the quietus on that. Buy your cables now, though. Big Brother reads this blog. By the way, the Democrat “Julia” ad? Julia was a character in Orwell’s 1984. Go figure.

  31. To find out more about this, you need to learn more about pyrotechnics, and in particular, Thermite and Thermate mixtures. Thers several site son the net, just google ‘pyrotechnic’

    Thermite of 75% Black Iron Oxide and 25% magnalanium powder (50/50 aluminium and magnesium) can be extremely hard to ignite. The solution is to mix the thermite mix with 29% Barium Nitrate, and use an electric ignitor. The thermite is in a metal box from Maplin with a hose clip holding it on top of the HDD.

    For an electric ignitor, use a 12v 40w car headlamp bulb. Break off the glass, exposing the filament and bury it into the thermite mix. Personally, I have this wired through an arm/disarm switch (which is a shorted out 2.5mm jack plug in a socket on the back) and a micro switch on the case cover, to a bank of 10 AA NiCad cells in series, which will supply the 5A current at 12v need to glow the filament and ignite the mix if the lid is removed withour disarming.

    You dont need to speed up the burn rate as suggested, in fact, adding the Barium Nitrate slows the reaction down, making sure the HDD melts. Thermite burns cannot be extinguished, they make there own oxygen, they will burn under water and in halogen gases.

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