What Are The Different Types of House Keys?

ADL-House keys

Locks and keys play an important role in our everyday lives. They’ve been around for centuries, and they’re primarily made for one vital purpose alone – to keep your property secure and safe.

In this article, we will examine the different types of keys and their uses, showing how they evolved and how they work. There will also be a particular emphasis on house keys and what to do should you lose your house key and need a replacement or simply want to get your house key copied.

By the time you finish reading this article, you may not be a qualified locksmith, but you will be significantly more knowledgeable about keys and their vital role in your day-to-day life.

Read here to learn everything you need to know about keys, how they are made, how they work, the different types of keys, and how they influence our lifestyles.

The Key Defined

A key is any device used to unlock a lock. Typically a key is made of metal with grooves and notches cut into it. Most keys have two parts – the bit and the bow. The key bit is the part that enters the lock, and the bow is the part that is left protruding from the keyhole on which the key user applies pressure to turn the key and operate the lock.

In its simplest form, a key has a pattern of notches and grooves cut into it, and these match a corresponding pattern inside the lock the key is designed to operate. Keys are essentially a form of security apparatus, and the general idea is that a particular lock cannot be opened except by the key it was designed to be opened with.

Metals commonly used to make keys include brass, nickel, and steel, and sometimes if it is an exotic key meant for decoration rather than security, it will be made from expensive metal like silver or gold.

The History of Locks and Keys

The earliest locks and keys appeared to be from Ancient Egyptian times, approximately 6,000 years ago. The Egyptian lock discovered by archaeologists was a wooden pin lock with a large wooden key. The locking mechanism had wooden pins inside and a wooden bolt. The wooden bolt had holes drilled in it, and the wooden pins would slot into these holes preventing the bolt from moving. The key would be inserted into the keyhole, which would lift the pins allowing the bolt to be moved.

The next big step in the evolution of keys came with the Romans when they invented metal locks and keys and the key ward system. The key ward is a series of protrusions or obstacles arranged in a set pattern, and it blocks the entry of any key that does not have a corresponding pattern. The correct key that opens a warded lock will have notches and grooves that match those of the ward pattern.

The Different Types of House Keys

The reality is there are many different types of house keys, and a house key is a lot more than just a standard metal key that unlocks the front door. Listed below are some of the more common types of house keys:

The Flat Key

A flat house key will be flat, slender, and rectangular shaped, and is generally attached to a key ring so it can easily be carried by the owner. In most cases, flat keys come in blank form from the manufacturer, and the professional locksmith cuts the groove and notch pattern onto the blank key.

Flat keys can be used as entry locks for the front door; however, they are usually used for opening padlocks, desks, filing cabinets, or security boxes. Each flat key will have a unique cut pattern corresponding to the pattern inside a particular lock.

The Corrugated Key

The corrugated key is commonly referred to as the paddle key because of its shape resembling a paddle, and they are made to open tubular-shaped pin-tumbler locks, which are commonly found on doorknobs.

The corrugated key is so called because it has a series of corrugations (or ridges) that correspond with the grooves inside a particular lock. The corrugated key is made from metal and has two sides with flat edges on one side and round edges on the other side of the key.

The Mechanically Cut Key

Mechanically cut keys are older designed keys that are made utilizing a mechanical cutting machine. The disadvantage of mechanically cut keys is that they are easily and cheaply duplicated, which means they do not offer high levels of security.

The Four-Sided Key

Many types of keys can be used as a house keys, but perhaps the most frequently used is the four-sided key. A four-sided key will have two or four pairs of teeth on either side of the key. The four-sided key is the most difficult to copy due to its intricate design.

Mechanically cut keys can be converted into two- or four-sided ones by licensed locksmiths. This will give a much greater level of security, which is essential, mainly if they are house keys. Typically, four-sided keys are not only harder to duplicate, but they are also more durable and less prone to damage or breaking.

The Dimple Key

As the name suggests, a dimple key is a key that has numerous dimples or indentations in the length of the key blade. These dimples are in a pattern that corresponds with the protruding pins inside a lock. The dimples and the pins line up exactly when the key is inserted into the keyhole, allowing the key to operate the lock.

Dimple keys are commonly used as house keys because they are easy to operate yet give an extra layer of security. After all, they are difficult to duplicate.

There are other types of house keys, but they are not as often used as the ones mentioned above. These include abloy, skeleton, magnetic, and digital keys.

How to Get Your House Key Copied

There are several ways to make a copy of a house key, including some do-it-yourself methods. However, it is strongly recommended that you contact a professional locksmith when making a copy of your house key. Licensed locksmiths have the right equipment that enables them to cut most types of keys quickly and accurately.

Security must be maintained when making a copy of a house key; this is another reason you should let a qualified registered locksmith do it for you. A licensed locksmith will also have insurance, which adds an extra layer of security for the customer when getting a key duplicated.


A house can become a home, and it is where we keep our valuable possessions. A home is where we store our valuables, which can include both emotional and monetary value. When a house becomes a home, security becomes a particularly important factor.

To secure your home from burglars and other intruders, it is essential to have a fully functional lock and key system. It will primarily include your front and back doors but may also include your windows and garage door.

The humble key has been an integral part of protecting our belongings for thousands of years, and in today’s world, it is still just as relevant. The lock and key are essential elements of any house security system.

What sort of house key do you have? Ask ADL about it!

Many people ask themselves, what kind of house key do I have? The truth is many different types of keys offer various degrees of security. Some keys are easily copied and replicated, while others are complicated and difficult to duplicate.

If you’re purchasing, upgrading, changing, or repairing your lock and key system, using a professional certified locksmith like Alexius Denver’s Locksmiths is always a good idea. Most people who require a Denver locksmith turn to us as we have the right people with the right equipment and expertise to do the job quickly and efficiently, ensuring that your home security will never be compromised. Call us today for all your locksmithing needs!

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