There are a few reasons why you may want to destroy a key – you’ve lost the lock it goes to, you want to dispose of an old key securely, or you simply want to get rid of a key you no longer need. Whatever the reason, destroying a key completely can be trickier than it seems. Keys are specifically designed to be durable and withstand force. Simply snapping a key in half or bending it won’t prevent it from being put back together or decoded. To fully destroy a key, you need to damage it enough so that it can’t be restored or duplicated. Here are some of the best ways to destroy different types of keys.
Cutting and Filing Down Metal Keys
Most traditional keys for doors, padlocks, cars etc. are made of metal. Cutting, drilling, grinding or filing down these keys can effectively destroy them. Here are some methods you can use:
Cutting the Key Teeth
Using bolt cutters or sturdy scissors, cut through each of the key teeth vertically. This will remove the unique pattern of peaks and valleys that allow the key to engage the lock. Be sure to cut through the entire width of each tooth so the shape can’t be reconstructed.
Use a power drill to make several holes through the head and shaft of the key. This will physically break the key into smaller pieces and prevent the cuts from lining up correctly again. Space the holes close together so the key is left mostly hollow.
Use an angle grinder or bench grinder to grind down the length of the key. This wears away the metal and destroys the unique profile. Be sure to grind past the end of the farthest cut to remove the full code.
Secure the key in a vise or clamp and use a metal file to aggressively file across the teeth and shaft of the key. This scrapes away the contours that align with the lock. File perpendicular to the cuts to thoroughly eliminate the shape.
Melting Down Metal Keys
For complete destruction, you can melt metal keys into an unusable lump of material:
- Use a propane torch to heat the key until red hot before pressing it together with pliers to deform the shape.
- Place keys in a smelting furnace or foundry to melt multiple keys at once.
- Throw keys into a lake of molten metal like an aluminum foundry to fully dissolve them.
Once melted into an amorphous blob, the key is impossible to identify or use. Just make sure to melt the key in a safe area clear of flammable materials.
Destroying Plastic Keys
Keys made of plastic, like low-security keys for filing cabinets, lockers and diaries, can be destroyed by:
Plastic keys are brittle and can be snapped easily by bending them back and forth until they break. Make sure to break any large pieces into smaller ones.
Use sturdy scissors or snips to cut up a plastic key. Dice it into small fragments that can’t be put back together.
Use a lighter or match to melt and burn plastic keys until no identifiable parts remain. Do this in a safe area away from anything flammable. Breathing in the fumes directly is not advised.
Place plastic keys in a jar of acetone nail polish remover overnight to dissolve them. This chemical reaction will liquefy the plastic into a useless goo.
Destroying Digital Keys
For modern keyless entry systems that rely on programmed RFID chips or digital codes, physical destruction may not work. Here are some ways to destroy digital keys:
Deleting Digital Files
If the key is stored on a phone, computer or cloud account, permanently delete the files. On a phone, delete them from the device memory as well as any online backups.
Clearing Computer Memory
For a key stored on an onboard car computer, try performing a master reset to wipe the memory. This will clear any digital keys programmed into the car.
On “smart keys” with batteries, remove any batteries to disable the transmitting chip. Without power, the code can no longer be read.
Deactivating and Reprogramming
Some digital keys can be erased and reprogrammed through a reset function. Consult your owner’s manual or the company that issued the key. New codes will need to be set up afterward.
Places You Can Destroy Keys
When it’s time to destroy your keys, make sure to do it safely in an appropriate place. Here are some of the best spots:
Your own property gives you space and privacy to destroy keys how you want. Just be cautious of open flames around structures and brush.
At a Business
Some businesses will allow you to destroy keys on their premises, like self-storage facilities and hardware stores. Call ahead to check their policies.
Scrap and Salvage Yards
These industrial sites have equipment like smelters to destroy metal objects. Staff can usually assist for a fee.
Businesses that responsibly dispose of e-waste can destroy digital keys by shredding circuit boards and storage devices.
Auto Dealers and Locksmiths
Professionals like these may offer key destruction services or machines you can use yourself under supervision.
Destructive Tools and Equipment
Having the proper tools makes destroying keys faster and more effective. Here are some go-to tools:
The blades of these heavy-duty cutters snip through metal with ease. Use them to chop key shafts and teeth.
Locking pliers can crush keys into compact shapes. Needle-nose pliers help hold small keys while cutting and drilling.
A bench grinder quickly grinds down metal keys. Angle grinders allow grinding in any direction.
A power drill with a small bit can pierce holes in metal keys, whether handheld or in a drill press.
Handheld blowtorches generate targeted heat to melt and deform metal keys easily.
The fine teeth of a hacksaw blade can saw through plastic and soft metal keys.
Heavy-duty scissors work for snipping plastic keys. Aviation snips cut tough metal.
A hammer can be used to bend, deform, and flatten metal keys beyond usability.
Wear protective equipment like goggles, gloves, and a mask when destroying keys to guard against debris, chemicals, and heat.
Destruction Methods to Avoid
Some common ways people try to destroy keys don’t work well and should be avoided:
While bending a key prevents it from opening the lock, it can often be bent back or decoded. Use other methods along with bending.
Cutting in Half
A key sliced in half can still be put back together and retain its key cuts. Make multiple cuts or slices instead.
Just hammering a key often only deforms or flattens it while leaving the bitting intact. Use additional methods like grinding.
Soaking in Water
While water exposure will eventually corrode some keys, most metal keys can simply be dried and still function normally.
Plastic keys will melt under high microwave heat, but metal keys reflect the radiation. This can also damage the appliance.
Coating a key doesn’t prevent reading by locksmiths. At best, paint just slows down wear and tear. The key underneath remains usable.
Alternative Ways to Secure Keys
Rather than destroy keys, you may want to just prevent unwanted access or copying. Some options include:
Storing Keys Securely
Keep your keys somewhere hidden where they can’t be found and duplicated without your knowledge. Options include a safe, bank vault, buried in your yard, etc.
Electronic Key Tracking
There are RFID tags available that alert you if your keys leave a certain geographical area so you can locate lost keys.
Installing New Locks
You can have new locks installed that your keys will no longer open. This prevents access without destruction.
“Do Not Duplicate” Keys
These restricted keys are only supposed to be copied by locksmiths with proper documentation, reducing duplication risk.
These advanced keys use encrypted codes that locksmiths can’t decode through duplication alone in order to make unauthorized copies.
Destroying a key completely requires inflicting substantial damage so that it cannot operate the lock or be decoded. The best methods for permanent destruction depend on the metal and plastic composition of the key. Using tools like bolt cutters, drills, grinders, hammers and fire effectively demolishes keys until they’re unusable. Cutting up, melting down, burning up or deleting a key’s code are all ways to fully destroy it and protect access. With the right techniques and equipment, you can demolish any key beyond repair.