EMP proof Safe Combination Lock

Will EMP Fry the Electronic Keypad Lock on my Safe?

Awhile ago I received this question from a reader:

Saw some articles on EMP (my biggest fear).

In a moment of stupidity I bought a gun safe with a electronic lock instead of a dial lock. I just can’t get it out of my head that this will be a epic disaster if an EMP hits.

I was looking to place some sort of protection over the keypad and have seen an article that a cage resting over it may be of some protection. But I have also seen some EMP protection bags which I thought if you sealed over the keypad would accomplish the same thing. I think they are like Anti-static bags you get computer parts in.

So my question is would this work? Or would the metal of the safe channel the pulse into the backside of the keypad and fry it anyway? Is anything kept inside a gun safe also proofed against an EMP? I would think it is, but curious.

I would suspect that yes, the electronic locking mechanism of a safe will be at risk during a EMP event.

Although electronic locking mechanisms can be really convenient, they also cause me concern. Why? Because they all need a power source and they all have ‘electronics’ inside which could ‘break’.

Remove the power source or damage the electronics within the keypad and you’re locked out (although some also have a physical key lock mechanism for backup functionality – important!).

EMP & Electronic Keypads

Electronic Keypad Safe Lock

Theoretically a nuclear EMP (electromagnetic pulse) at altitude may zap the atmosphere with up to 50,000 volts per square meter. Wow! There are caveats to that, however one might presume 50 KV may likely ‘fry’ electronic circuits! Even electronics not connected to the grid (a safe’s keypad) will receive a charged field jolt (again, with theoretical caveats).

Related: Nuclear EMP Components E1, E2, E3, and what they mean…

One accepted exception to this is the concept of a Faraday cage. A conductive skin (or small enough mesh) enclosure which would theoretically protect electronic contents inside (with enough dB attenuation at affected frequencies).

When we start talking about this, it gets technical (beyond the scope of this article). However there are factors such as strength of field, attenuation, and the electronic device itself. However I will offer a general opinion about the Safe and its Keypad…

If the safe is not entirely made of conductive metal, the EMP will get in.

Additionally, they have doors and therefore a gap around the perimeter. Depending on door design (gap dimension, folds) and EMP frequency bandwidth (wavelengths), some of the field strength may get in.

A electronic keypad is entirely exposed on the front surface. It will receive whatever ‘zap’ exists at that location during EMP.

Even if you cover up the keypad with conductive tape or mesh, there’s a problem… The safe is covered with paint or epoxy/enamel of some sort. The tape would need to be in conductive contact with the metal itself around the perimeter of the keypad. Are you going to scratch off all that paint on your pretty safe, just in case?

Anti-static Bag

The reader question mentioned Anti-static bag material. This is an interesting thought. That is, cover the entire safe with some sort of Mylar conductive foil bag.

The problem for starters is this: the bag might have to be pretty big… I’m not aware of ‘garbage bag’ sized Mylar bags.

Maybe one could be made from “Emergency blankets”. You know, those so called “space blankets” made of Mylar foil. Maybe cut them up, overlap edges and tape them together to form a bag sufficient to cover the safe. Sounds pretty ‘cheesy’.

Before covering with your makeshift Mylar Faraday bag, you might first cover the safe with a blanket to electrically insulate the safe itself from the conductive material.

Then there’s the problem of the bottom. How heavy is that safe?
See where I’m going?

All this sounds like quite a pain in the arse!

EMP proof Closet?

You might theoretically transform one of your closets to be EMP resistant. Maybe it’s tinfoil hat theory, but maybe not…

Line the walls, ceiling and floor (and door) with conductive material (more Mylar?) or fine metal screen mesh.

Then put a carpet or plywood on the floor to insulate.

You could keep your Safe (with its electronic keypad) inside this room (along with other electronic ‘stuff’). Would it work? Maybe, to an extent (with a bunch of theoretical caveats and such).

Did you tape all the corners, edges, to make it all conductive together? Then there’s the issue of the door edge perimeter gap.

How much attenuation (dB) would you actually get with just one layer of Mylar (probably not too much)? Would it be enough? “It depends” (don’t you love that answer?)

Again, a pain in the arse…

EMP Garbage Can

Will your safe fit inside a metal garbage can (makeshift Faraday cage)?

Probably not.

Here’s the solution to the Safe problem!

Buy a Safe with Combination Lock!

Next time, just buy a safe with a good old fashioned combination lock or key. Or at least a safe that has a alternative manual key to get it open.

Example: Extra Large Combination Safe

For my pistol safes, I have several biometric (fingerprint reader) safes. They’re excellent! I’m not worried about EMP. Why? Because they also have a key!

Biometric Pistol Safe

Related: Biometric Gun Safe Review Of SentrySafe Pistol Safe

That said, if you’re in the market for a personal Safe or a large upright gun safe (rifles, etc..) and if you are concerned about EMP, I would recommend getting one with a combination lock (or a backup key lock). Simple as that. It does make for slower access, but that can be dealt with in other ways.


  1. 99% of Electronic Safe’s can be converted to Manual Locking. Ya don’t need to buy a new safe or trying to sticking it into a Faraday Cage
    Call your local Locksmith, empty it before he gets there.
    BTW, Most Locksmiths have access to every combination (Manual and Electronic) you can imagine, just from the Model & Serial Number of the safe they can get into it.

    1. When I bought my first safe, it was electronic/key. I wasn’t even thinking about an EMP, I was thinking about how to access if the battery died. Sure enough, I didn’t access at one point for several months and the battery died so I used the key and was good as gold. My friend wanted to buy a safe on Black Friday and it was electronic. Made sure to double check to see if it had key access as well. Damn, that safe was heavy. I think I will add that to the list of things where I will be mysteriously busy such as moving, roofing, and plumbing. Hehe

    2. Not entirely true. I am a locksmith and I can access key codes and lock info. The trick is that it is via a number stamped on the back side of the lock. Example: most automobiles have a number stamped on the passenger door key lock that give the cut code for the ignition. To make a key for the car all you have to do is disassemble the passenger door.

    3. Just had mine switched. Completely worth the $230. I had been keeping the safe unlocked just in case, which is obviously ridiculous.

  2. Ran into a acquaintance a while back who was buying an electronic lock for his front door. He is a hard core prepper with a compound that looks like a fire base from back in the 70s. I asked him if we had an EMP or CME would he be locked in or locked out? I think he stayed with his key lock.

    I’ve always been hesitant to get a bio-metric lock as I had nothing but problems with the one on our medication dispenser at work. Doing a lot of home remodeling at the time and using a lot of sandpaper. My fingerprints were constantly being worn down and the machine had a great deal of difficulty recognizing me.

  3. I’ve got power and hand tools plus the ol smoke wrench..
    Anyone need a safe opened, emp or not I get one gun of my choice for access : )
    Betting the huge chopsaw will work after emp/cme, somewhat positive about my generators because there is little to no electronics in them.

    I got (2) long gun safes from homedepot around 12 years ago real cheap because
    store personnel lost the combinations to both,
    50 for one, the other free for removing it.
    One was locked the other wasn’t.
    The locked one I cut the back open, dissembled the door from within to open it
    and bolted a large steel plate over the hole that was only roughly 8″x7″ and made sure
    no body would get in as easy as I did.
    Sentry model G5241 with internal hinges, not the greatest, not rated for fire but
    frigging wonderful for the price.
    Supposed to be 14 long gun but it is too small for that, near 300 pounds each empty.

    I actually had fun figuring out the combinations forward and backward on them

    1. I bought a gun safe with an electronic keypad a ways back before I even knew what an EMP was. The novel, One Second After, changed that.

      I bought a dual lock that function as both an electronic keypad AND a manual combo lock and had it changed out. Best of both worlds. Query “Safe Logic X-treme Lock” and that should point you in the right direction.

  4. I own a fire proof combination safe for my important papers, wife’s jewelry, and emergency cash. I don’t own a fire proof gun safe for a couple of reasons. My home is on a pier and beam foundation that would require reinforcement to carry the weight of one large enough for my collection. Instead, I opted for several of the single walled steel key locked safes mounted in my safe room/walk in closet w/fire sprinklers.

    I passed on the fire proof safes after looking at several on display at a dealer. There were several brand names, but all had the electronic keypads. A factory representative happened to be there that day, and I posed the question of how I could open it if a thief destroyed the keypad trying to open the safe. He said “Oh, just call us and we will come open it for you”. I asked how they opened it and he said “with a special key-like tool that fits an over ride mechanism behind the keypad”. I asked if the key/tool fit all their safes or only the safe I might buy. He answered, “No, one key fits them all, that’s why we can’t let anyone have one. You must call us to come open it, but don’t worry, we don’t charge for that service.”

    I just didn’t like the idea that a third party could open a safe that I own, but I can’t. This sales rep might have not known what he was talking about, but it sure scared me away. Years of law enforcement experience tells me that “special keys” stay “special” until the first untrustworthy employ duplicates it. When you pay a $1000 and up to purchase a safe, your telling the minimum wage cashier that you have something worth a heck of a lot more that you are putting in it. Most times they will also have your name, address, and phone number readily accessible.

  5. Have a small Stackon electronic safe, batteries came loose and was locked out. Looked on you- tube and saw how to open it by hitting the top with a rubber mallet while holding lever. Yup, popped right open. So much for security. My long gun safes are double key lock Stackon affairs more like heavy lockers with barrel locks. I subscribe to the multiple hide theory. Electronic locks? Nope, never for me. Too vulnerable.

  6. Even though my thoughts on an EMP happening are highly unlikely, I think a cyber attack on the power grid is a more likely scenario, when I bought my gun safe I bought it with an EMP as a possibility in mind and bought an old fashioned Sargent and green leaf combination lock. Yeah it take me a little longer to get in my safe than an electronic lock, but I know I’ll always be able to get into it.

  7. Our safe weighs in at 900+ pounds EMPTY. I was concerned about the digital keypad but it had better UL ratings than the Brownings, was bigger, and cost less than half their price. The big difference was it didn’t have all that fancy wildlife scenery painted on it in gold and had a hammered finish instead of glossy. My wife and I both agreed that we were not going to set our safe in the living room as a centerpiece. In fact, we didn’t want anyone to know we had it in the first place so “pretty” was not an issue.
    After purchasing it and getting it home, I called the manufacturer and asked about the keypads vulnerability to an EMP from say… a CME. After talking with several departments and getting the old “I don’t know” from everyone, they sent me a spin dial combination lock for free. In the process, I learned a few things…

    The actual combination on those digital keypads is NOT stored in the pad. It is stored in a small electronic component inside the door that the pad connects to. This makes sense. If the combination was stored in the pad, all any thief would need to gain instant access to thousands of safes would be his or her own digital keypad. Unplug the victims pad, connect their own and beep-beep-beep= instant access.

    Because the combination is stored and accepted/denied by an electronic device concealed inside the door, it is probably vulnerable to EMP. The door is only “connected” (think electrical path) to the body of the safe at the hinges. These may or may not provide an adequate path for discharge if the body of the safe is electrically grounded.

    In most large gun safes, the ONLY thing that actually prevents one from spinning the handle to open the door is a rather small piece of metal that when locked sits down in a locking notch on a geared rack that the door securing bolts are connected to. When it is unlocked, this little piece of metal is pulled up out of that little notch, freeing the rack to be moved by the safe door handle. When you are using an electronic lock, you can usually hear a faint click when you enter the combination. This is a solenoid activating and pulling that little piece of metal up out of the locking notch. When you use a spin dial, that little bit of resistance you feel after entering the last number of the combination and then turning the dial to “open” the safe is the last interior dial lining up allowing the back end of the little piece of metal to fall into secondary notches. When you feel that resistance, you are manually forcing that metal up out of the locking notch. From what I have been able to learn, most home safes work on these two principals.

    Almost every single safe can be easily converted from digital to spin dial. If the company will sell you the spin dial mechanism, you can likely do it yourself. Either way, a locksmith can easily do it, but then you have someone local who knows you have the safe, where you live, where it is in your house, and perhaps even the combination.

    I’ve also learned that in an emergency, many of those smaller bio-metric style safes can be opened by literally hurling them at a hard surface such as a concrete floor. Read about that online and it was confirmed to me by a few locksmiths.

    Like Dennis wrote, there are some safes that have a special key or device that will open any of the safes made by that company. I would strongly recommend you do NOT get one of those. Those keys are “out there”.

    Our new home is also on a traditional beam foundation, and our safe is VERY heavy. Simply go to Lowe’s and buy a few concrete masonry units (certain kind of flat cement blocks that cost about $7 each) one or two adjustable floor jacks (about $30 each) and a few 2×8 or 4×4 or 6×6 beams. Get under your house in the crawlspace underneath where your safe is or will be. Measure out how long your wood components need to be in order to either support the beams under the safe, or fit between the beams and support the subfloor directly. Cut the wood components to size.

    Put one CMU on the ground, put the adjustable jack on that, put one CMU on top of the jack, then put the wood on top of that. Jack it up until it is pressing slightly against the beams or the subfloor underneath your safe. This will transfer much of the weight from the house beams to the support you just installed. This is how load bearing walls are supported in many traditional foundation homes.

    We hope everyone had a Merry Christmas, and wish us all a very happy, prosperous, and safe 2019!

    1. This RestoringBrad, I was told by safe co buy extra keypad and put in faraday can…quests you proved that worth less. need to order some dail locks thanks again for GOOD INFO

  8. So I’ve been told – a student had pedalled to the university, locked his bike and attended class. When he returned he found that the bicycle had been stolen. Annoyed, he went to the metallurgy department and asked if they could develop a metal that would resist bolt cutters and leverage which they did. The student left university and developed the Kryptonite Bicycle Lock (and made his fortune).

    I have one for my root cellar door.
    Stay frosty.

  9. I got mine years ago by default. A former family member asked for help purchasing one. When they left the family the safe stayed behind in lieu of payment. I called the manufacturer a while back but they said there was no manual lock option. They have only electronic lock safes for sale. Calling a locksmith will go on the JIC list.

  10. I have a large safe, and when I bought it, I had the dial combo changed out for a digital. This last year I contacted the manufacturer and am getting a dial lock for it. After that I will change out the rubber seal with one that is “comductive” (copper wire infused). Hoopefully that will be enough. It’s only $150 (installed) to change out the lock on a safe I bought 20 years ago for $2000+, cheap insurance, IMO.

  11. Some yrs ago I purchased safe from a local big box store ( nationally known ) with a electronic key pad ( my wife’s idea ). but one of the items that came with the safe was metal key ( similiar to the old fashion ones ) to used just in case the key pad stops working. It’s kept in another place with a dial lock on it. The older century safes of 50 plus yrs ago could be opened by turning them upside down and hitting them with a 8 lb sledge hammer about 2 times and the door would or should open. why, because they were built loose enough come open because of the vibration

  12. Mechanical locks are the only way to go, all my safes are old, heavy and non-electronic.

    Nothing wrong with new electronic toys, but I will never be convinced that electronic safes are the way to go.

    I would hazard a guess that electronic locks are less expensive to make so that is what they put in many modern safes.

  13. Timely subject. I was worried about this very thing so last week we had the electronic lock changed out on our safe for a manual dial. Cost $300 but gave me better peace of mind.

  14. It was several years ago on the Weekend post that I shared about my small safe with electronic “keypad” type of lock froze up and died. There was an option for the manual key for use as backup butt that option did not work either.

    I called a.locksmith to come to the house and he drilled out the lock. It took about a half an hour to do so. While he was doing that he stated: “Yeah, I have been getting a lot of calls to drill out these safes recently. Yours is the second one this week.”

    The small security cabinet was made by Stack On and it was purchased at Sportsmans Warehouse. It worked well for between 2 to 3 years before it died. When it died, I had to call a locksmith and drill it out.

    At time of purchase over 5 years ago, all the options for safes and security cabinets were going the way of electronic keypad type of locks. The last time I went to Sportsmans Warehouse to purchase a replacement, thankfully most of what they had was mechanical locks with use of keys.

    Memories are short so if you currently have a safe or security cabinet with electronic keypad type of lock, I would replace it with a good old fashioned mechanical lock. I hope the security industry will remember the inexpensive electronic locks are a bad idea unless owned by an electrician that knows how to bypass the lock mechanism.

  15. Personally I don’t believe in electronic. So if I need to choose I will take a mechanical lock. In my country is impossible to get one good safe. Only made in China. People are poor to buy safe. Usually there is one steel cabinet with lock for weapons. That is law obligation for weapons but most of owners haven’t one. I need one to. Not only because law says that. I have little boy in house and I need to prevent him to get a weapon when he is alone. For security I have insurance. It is cheaper than to buy a safe. I have secured door on my flat. Probably is not a problem for professional thif but I suppose professional one will choose better target. For junkie it would be enough. I hope that!

  16. Before the EMP will likely come a build up period of increasing tensions. That is the point where you might want to open the safe and get everything out and organized for ease of access. If your firearms are in the safe when the SHTF you will have little time to prepare for the next step. If you store your firearms unloaded in the safe, you might want to have them loaded and ready.

    Thought: gun control idiots want guns which imprint rounds, have electronics to prevent unauthorized users, etc., but I wonder if they have even thought about the impact of EMP. I also wonder what will happen with all our military equipment which is so heavily dependent upon electronics. And, what impact will be on humans whose brain is essentially run by circuits dependent upon electrical impulses. Will we even have the ability to wonder about getting to our gun safe and it’s contents?

    I do especially like the idea of converting a safe to manual.

  17. Connecting your metal safe to a good earth ground would make your entire safe a faraday cage.. You might run a wire from the safe to the door to make sure the door has a good ground. Last make a faraday cage for the digital lock. That can be anything metallic that is grounded out.

    This may sound silly but it would work! Cover your entire safe with aluminium foil and connect it to an earth ground….. Those Crazy people with tin foil around their heads might be crazy but they were not STUPID!

    1. To be clear (for others who may read this), a Faraday cage does not need to be grounded. I’ve written a number of articles on this, however the following article has a section in it that describes this in more detail:

      Thoughts Regarding Faraday Cage Techniques For An EMP

      Here is an excerpt:

      What is a Faraday cage?

      It is an enclosure (shield) formed by conductive material or by a mesh of such material. Such an enclosure blocks external electric fields by channeling electricity along and around, but not through, the mesh, providing constant voltage on all sides of the enclosure. Since the difference in voltage is the measure of electrical potential, no current flows through the space.

      A Faraday cage operates because an external electrical field causes the electric charges within the cage’s conducting material to be distributed such that they cancel the field’s effect in the cage’s interior. Faraday cages are named after the scientist Michael Faraday, who invented them in 1836.

      An ideal Faraday cage is a conductive metal box (on all sides). Contrary to what many believe, the Faraday cage does not have to be grounded to do its job. If you have trouble with that statement, do some research (web-search) and you will discover the physics. The Faraday cage keeps the charge (EMP) on the outside (during that fraction of a microsecond (nanoseconds) until its gone) while a grounded Faraday cage will simply bleed the charge to ground during that same fractional microsecond. In either case, the electronics inside are protected (to the extent of the construction properties of the cage itself).

      Note: Faraday cages are intentionally grounded when the intended use is to operate an electronic device inside (e.g. a Faraday enclosed room) while the electronic device itself requires a proper ground (and proper isolation techniques from the incoming power source).

  18. Bazerkly;
    A Faraday Cage does NOT need to be “grounded” to good old Ma Earth.
    Please do a slight more research.

    1. Yup,
      Faraday cage needs to be isolated not grounded, grounding it will give the pulse etc a path to ground through your faraday cage

  19. Little note on mylar, those “survival blankets”- useless.
    It does not block cell signal or wireless internet so It’s unlikely to do anything but a false sense of security.
    It does weakens the signal somewhat, that’s all.

    I can wrap my cell phone up in the stuff and it still functions as a wifi point.

    1. Horse,
      Regarding cell phones, most operate in the range from 1.9 GHz to 2.1 GHz. And cell phones are able to pick up signals that are very weak. The so called cell phone test isn’t always entirely telling. There’s more information in the following article:

      [ Read: Faraday Cage For The Prepper, Just in case… ]

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