What came first, the lock or the key?
We may never know.
But what we do know is that the concept of the key is old—at least 3,000 years old.
If our history is correct, the Egyptians were the first civilization to utilize locks and keys. However, in those days, it took a full-grown adult to carry around a key.
Today they are small and easy to lose. But they are also quite simple creatures.
In this guide, we'll cover in-depth the 9 parts of a key and how they work in a lock.
Let's get to it!
Table of Contents
Parts of a Pin Tumbler Key
The purpose of the key is to move internal components to the correct positions so that they no longer obstruct the shear line.
We'll talk more about the shear line a little further down this guide, but you can learn more about it in my ultimate lock picking guide.
The key is comprised of 9 main parts:
The blade is the long section of the key that is inserted into the plug of the lock.
This is also the functional part of the key that contains the cuts, bitting, warding, and tip.
The top of the key is the edge with cuts, while the bottom is the edge opposite of the cuts.
The bow, or head, is the large meaty section of the key and serves as a handle to turn the key.
This part also contains important information such as manufacturer name, key-codes, and type of keyway.
This gives the key a lateral restriction that aligns the key perfectly with its matched key pins. In a nutshell, it stops the key from entering past a certain point.
Without this, we wouldn't have any idea how far to push the key into the lock.
Not all keys have shoulders, and some utilize the tip of the blade to stop the key.
The tip is the end of the blade and opposite the bow. It is what enters into the keyway first.
Some locks utilize the tip to stop the key and align the cuts.
These are the cavities that are cut into the blade and make up the bitting of the key.
Cuts are various depths and are essentially the combination code that matches the pins in the lock.
Some keys have cuts on both edges of the blade—such as a car key.
The keyway of the lock determines the profile and overall shape of the key's blade.
When inserted, the shape of the key matches the shape of the lock's keyway perfectly.
Said another way, the key is the puzzle piece, and the lock is where you place that puzzle piece.
The lock's warding is essentially the shape or formation of the keyway, and this shape protrudes through the entirety of the lock.
Keys are manufactured to fit their lock's exact warding shape. This is an added security feature as it only allows the user to insert keys with that exact same warding. It also helps hold the key snug in the plug when inserted.
Manufacturers can sometimes get really creative with the warding. Extreme warding, such as paracentric keyways, adds another layer of security as the more extreme it becomes, the harder it is to pick—at least if you don’t know what you are doing!
The Key Bitting
The cavities that are cut into the blade of the key are essentially a combination that, when matched with the correct length of the key pins, will open the lock.
In the case of a pin tumbler lock, when the key is inserted, the bitting interacts with the key pins and lifts them to their appropriate position.
Engraved on the bow of the key can be a variety of information regarding that particular key.
Things you can commonly find stamped into the bow of a key are:
- Manufacturer information such as name or logo.
- Type of keyway the warding matches.
- The bitting of the key.
Some codes require a manufacturer codebook to decipher. These are called indirect key codes.
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How a Key Works
Now that we understand the anatomy of the key let's look at how a key works in a pin tumbler lock.
Watch the animation below, and we'll discuss what is happening after.
As you can see, when the key is shoved into the plug, it pushes upward on the bottom set of pins—the key pins (red).
Because the bitting of the key and the lengths of the key pins have been cut to match, the key pins will rise to their appropriate location and no longer obstruct the lock from opening.
Sum It Up
As we can see, keys truly are simple tools with simple parts.
I hope that this guide helped you understand the different parts of a key and how they work in a lock.
If you would like to learn more about lock picking and security, consider checking out my Academy for more free guides. Also, if you are interested in learning lock picking, be sure to stop by the shop and check out our selection of beginner lock pick sets.