Revolar is reader-supported. When you buy through links on our site, we may earn an affiliate commission. Learn more

What is a Skeleton Key? How Does It Work?

Fact checked by Teddy B.Miller

what is a skeleton key

Ever wonder why there is a vintage-looking key that opens all locks? You might be encountering what is called a “skeleton key”.

A skeleton key’s definition is a type of key that can open different locks thanks to a distinguishable hollowed inside bit. Furthermore, its removed serrated edge allows it to pick a skeleton key lock.

Now that you know what is a skeleton key, here are some other interesting facts about how it came to be!

History of Skeleton Keys


After learning the skeleton key’s meaning, you might be interested to know its origin story.

Skeleton Key’s history can be traced back to 4000 BC, when Roman soldiers used this type of key to access their enemies’ businesses and homes. They would rob them of their valuables while maintaining discretion and anonymity.

In the medieval age, nobles used it to escape back doors in times of crises. Commoners used skeleton keys to pick locks.

Nowadays, skeleton keys are getting phased out due to the rise of modern locks, which are more secure and cannot be opened with skeleton keys.

Purpose of Skeleton Keys

There are different purposes for why people get skeleton keys. Some business owners want to access their businesses with just one key for convenience. 

Some landlords also make use of skeleton keys so that they can have access to the doors of their tenants, especially in times of emergency.

How Do Skeleton Keys Work?


In order for skeleton keys to work, the locks should have the same lock mechanisms so that they can be opened with just one key. When you look at the parts of a skeleton key, you can see that the jagged edge has been filed down to accommodate different locks.

So why is it called a skeleton key? Because its serrated edges have been filed down or removed , the key has only parts which are considered essential, which look like a skeleton made of bones.

Are All Skeleton Keys the Same?


According to the identification guide, skeleton keys are not the same. This is because some skeleton keys have different barrel diameters and the key bit’s cut and size, which decides the type of locks they can open.

If your skeleton key cannot open your antique cabinet or chest, you might want to consult your locksmith if they have other master skeleton keys that can open them.

Pros and Cons of Skeleton Keys


Like any other keys, skeleton keys also have their ups and downs when you use them. Here are the pros and cons when you use a skeleton key: 

1. Pros

  1. Convenience: Since a single key can open all your locks, you don’t need to carry a lot of keys anymore, making it lighter for you to move around and travel.
  2. Efficiency: You don’t need to look for the right key to open a certain lock. You just pull your skeleton key, and you now have access to the room or chest.
  3. Security: Since you don’t carry a lot of keys anymore, you are more inclined to secure your single key.
  4. Cheap: Compared to other types of keys, skeleton keys are cheaper since you don’t have to modify the major parts of your key, unlike master keys.

2. Cons

  1. Safety: If your skeleton key gets lost, unauthorized people who will find your key can use the key to access all your locks. 
  2. Theft: Businesses with warded locks can be accessed by a skeleton key, which thieves can take advantage of and make illegal entries. 
  3. Durability: Due to skeleton keys being filed down, such as a folding skeleton key, they might become easy to break, which forces you to make or find replacement skeleton keys. 

Cost of Skeleton Keys

Since skeleton keys are no longer valuable and are only used for aesthetic purposes, they come off cheap. You can get one for around $10 or even less if you buy them in bulk.

However, for skeleton keys that have significant historical value, they can fetch for a higher price. For instance, a 1950 skeleton key was sold for $550 since the key’s bow had an engraved face on it.

The Symbolism of Skeleton Keys

Skeleton keys are sometimes used on Halloween because of their vintage look and spiritual meaning. Antique skeleton keys also symbolize the key to opening one’s heart, the key to becoming successful, and the key to unlocking all the doors. 

Some skeleton keys are also used to symbolize art. They are usually framed and displayed on walls. Some also use skeleton keys to make jewelry or even wind chimes.

Frequently Asked Questions

Why are skeleton keys no longer used? 

Since the invention of modern locks with warded locking mechanisms, skeleton keys have stopped being used. This is because skeleton keys cannot open multiple pin-tumbler locks since it doesn’t have the “teeth” to set the pins inside the lock. 

What is the difference between a skeleton key and a master key?

Skeleton keys are used in older times to open multiple locks with a single key. Since warded locking mechanisms were often used, it was convenient to create a skeleton key by filing it down. Hence, it fits and unlocks multiple locks. 

On the other hand, newer locks are designed with pin tumbler locks, which cannot be opened just by having a filed-down skeleton key. That is why master keys, which are basically modern skeleton keys, are designed to set the pins inside multiple locks to open them.


Learning about antique things that existed for thousands of years is interesting, especially if you have a knack for history. It adds to your stock knowledge and makes you more open to other interesting facts and materials that existed in the past.

Knowing the answer to “What is a skeleton key?” comes a long way. You can now identify skeleton keys and let your family and friends know how they became famous and useful back in the day.

5/5 - (2 votes)