15 Types of Keys: Explained With Example Pictures

Adrian Rodger

By Adrian Rodger

Last Updated on July, 2024

The lock and key mechanism is the driving inspiration behind significant security systems. Lock and key have been around since the years 870 and 900. 

Naturally, they have been updated, so much so that we have countless shapes and craftsmanship for regular keys and those that open a specific lock. 

The number of keys I’ve encountered while researching can not be squeezed into this written piece. 

They have evolved worldwide from fascinating antique pieces to modern intelligent car keys. This evolution allowed us to keep our homes, garages, offices, and even special lockers from intruders. 

So, we’ll go over fifteen of them, but some are considered subcategories of others. Some of them are a mixture of two different types of keys.

Quick Summary

  • There are fifteen primary types of keys, including flat keys, dimple keys, transponder keys, and antique keys, each designed for different types of locks and varying levels of security.
  • Keys have transformed from traditional antiquities to modern, smart car keys, serving as a crucial element in securing homes, offices, and other spaces. The lock and key mechanism, which has been vital in security systems since the 9th century, continues to play a major role worldwide.
  • Some of the most secure types of keys include double-sided keys, high-security keys with sliders, pins, and sidebars, and paracentric keys. Antique keys also have cultural and aesthetic value.

Types of Keys

picture of a bunch of keys hanging in a table

Different types of keys are used for different locks. The primary fifteen types are:

  • Flat keys. 
  • Corrugated keys. 
  • Transponder type of keys. 
  • Access cards used to open doors. 
  • Dimple keys. 
  • Double-sided keys.
  • Master keys. 
  • High-Security keys. 
  • Wafer tumbler keys. 
  • Abloy key. 
  • Paracentric key. 
  • Rim cylinder keys. 
  • Smart keys. 
  • Mortise cylinder keys. 
  • Antique keys. 

Some of these are designed for locks that are almost impossible to pick. So, let’s start. 

Flat Keys

This type has a flat, thin, and rectangular surface, distinguishing it from others. It is for older pin tumbler locks, and the manufacturer only partially makes it.

The locks are sent to a locksmith for individual markings. This unique pattern makes it hard to duplicate, even if the owner wants a second key.

If you have one of these and want a copy, use the right key. 

Padlocks are convenient locks for gates, lockers, and storage units. Padlock keys are an excellent example of flat keys. 

a picture of a flat key

A Flat key is very sturdy, so it can be used for a long time as a house key. Padlocks have also changed, but the classics still work with them. 

Cabinet keys come in various formats and styles. If you choose cabinet locks with a high-security feature, they may even have a code system. However, a traditional cabinet key is an excellent example of flat key. 

Because not all flat keys are hard to duplicate, having them for your cabinet can be convenient if there are more than two authorised people with duplicate keys. 

Corrugated Keys

They have complicated wavy cutting on the edges that make it hard to pick them.

Locks for corrugated keys give high-level security, and they’ve been used in the past for important buildings like government institutes. 

This intricate design is an art that no key-cutting services can produce.

A pin-tumbler lock is a great example. Crafting keys for these locks has long been a skill associated with vintage cabinets and cash registers.

Pin tumbler keys are well known for the cuts corresponding to tumbler locks.

The pin tumbler keys align themselves with the pattern inside the lock to work, making an excellent example of corrugated keys. 

a picture of an old corrugated key

Transponder Keys

They are commonly used mainly for the modern car key system.

They have a unique electronic chip inside lock mechanisms that communicate to the car’s system, ultimately unlocking the vehicle. 

The car also checks for the correct key code on the chip when you insert the key in the ignition. 

Only the correct key has the code to send a signal to the car, which allows you to start the car.

This mechanism has significantly decreased the number of car thefts.

a picture of a person holding a car key

These are the most commonly seen types, yet they are popular because they work so well to protect your vehicles. 

Sometimes, people refer to these as electronic or valet keys. This is because the electronic single that this key uses to unlock a car is electronic. The transponder key has played a role in eliminating car theft.

Access Cards Used to Open Doors

These are referred to as access cards but also known as card keys. You’ve seen them used for hotels, educational buildings, offices, and sometimes house keys.

This key type uses magnetic stripes, RFID (Radio-Frequency Identification), NFC (Near Field Communication), or smart chip technology to secure the lock.

It is the best security system for an office where many employees need access to different floors. 

The reason is that the card unlocks a door based on the information encoded. 

a person using an access card to open house door

Dimple Keys

This type has dimples or depression marks engraved on a flat surface. In many ways, it’s not very different from the flat keys.

However, the dimples on the surface are unique and allow an extra layer of security. 

Locks for this type are tough to pick because the pins in the lock align perfectly with the dimples. 

Other names for Dimple keys are button, bump, or dot keys. Many locksmiths recommend locks that use a dimple key as a house key.

They are also primary keys for vehicles and business locks. 

a picture of a dimple key

Double-Sided Keys

A double-sided key has cuts and notches on both sides of it. This arrangement allows the key to unlock from both sides.

It seems easier to pick but is more challenging than other locks. 

Having cuts on both edges means more pin arrangements inside the lock, allowing more possible combinations. Hence, it’s harder to pick and duplicate. 

Double-sided are also the most commonly used for cars and can be used in many locks.

Besides the apparent fun fact of a double-sided key working in either direction, it’s loved for its design, too. 

a picture of a double sided key

Master Key 

The most common use of a master key is in offices, apartment buildings, and governmental buildings.

Although it is convenient, it’s essential to control the use of this key to avoid unauthorized access attempts using one. 

One way of avoiding this is to keep the primary key to the access control systems protected in the control room.

This key type is different from any other kind because it is designed to unlock multiple locks; each lock also has its key. 

This key poses a risk to security because if it ends up with an unauthorised person, the entire building can be exposed. It’s best to safeguard a master key adequately. 

a picture of a master key

High-Security Keys With Sliders, Pins, and Sidebars

Some locks have exceptionally high-security mechanisms.

They have pins, sliders, sidebars, and even biometric authentication, making them resistant to drilling or tampering. 

These advanced-level security locks are for commercial, industrial, and residential use. A sidebar key, also called a laser-cut key, is an example of this key type.

Sidebar keys are widely used in high-security locks, mainly for cars.

a high-security key with sliders, pins, and sidebars

Their design creates an extra groove on the key, which slides perfectly with the insides of the lock to unlock it. This extra groove gives them the name Sidebar Keys. 

This level of security is considered modern; hence, it is used to prevent car thefts because key duplication for such a type is nearly impossible. 

Wafer Tumbler Keys

Wafer Tumbler keys are for a wafer tumbler lock with flat wafer key pins designed inside the lock instead of regular pins.

This untraditionally designed key type allows extra security for wafer locks, which can only be unlocked with a wafer tumbler key. 

Although the design is unique for this key, they are still used for low-medium security. 

The inside structure of a wafer lock has a rotating part that moves with the pin tumbler key, a stationary cover, and several spring-loaded wafers.

Sometimes, a mixed key is manufactured for the lock’s pins and wafers to make them extra secure. 

a picture of a wafer tumbler key

Abloy Keys

Abloy is a Finnish Company that manufactures locks with a unique cylindric and disc-like rotating mechanism.

Abloy is a very well-known brand, and its locks are one of a kind. 

The disc cylinder design rotates when the key is aligned in a specific pattern to unlock.

Their locks are also built for extended durability, giving high security with minimal maintenance. 

This key type is specially made for abloy locks. They proudly make their key distinct from any other. 

a picture of a abloy keys

Cylinder keys are used to turn the disc for locks with cylinder mechanisms. Others, not just Abloy, need a cylinder key. Cylinder keys are used in various places, such as homes, offices, and stores. 

Cylinder keys are crafted with solid materials like brass. They consist of a long blade with cuts on both sides to fit the pins inside the lock. 

Paracentric Keys

A Paracentric Key is one of a kind. They are designed with a special feature: warding. Warding is done by creating little bumps on the key’s blade.

The bumps work well to prevent break-ins, even with a lock-picking tool. 

This key type is why people have trusted such locks to keep government agencies and data centres safe.

They are sturdy and long-lasting but can be used only by authorised persons or licensed locksmiths because the warding requires a particular skill. 

a picture of a paracentric key

The Dimpled Paracentric Key is an extraordinary mixed key of dimples and paracentric. It is used for locks that need dimples and cuts on the key to turn and unlock. 

They have a narrow and intricate design to create an obstruction, giving it the ultimate security from picking and manipulating attempts. This correct combination creates a very high-security system. 

Rim Cylinder Keys

Rim Cylinder Locks are designed for wooden doors of houses, apartments, and commercial and car doors. One particular thing about these locks is that they are mounted on the door’s surface instead of inside. 

Rim Cylinder Keys are manufactured specifically for Rim Cylinder locks. They have a shape with sharp edges, making them unique to the rim cylinder’s modern locks.

When the key is inserted in the rim cylinder lock, the edges fit in, allowing it to get unlocked. These locks have anti-bumping and anti-picking mechanisms to prevent unauthorised access. 

Smart Keys for Electronic Locks

Smart keys are another name for electronic keys. These are highly advanced security systems on vehicles.

The idea of smart keys is to secure cars with smart locks and electronic technology that can’t be manipulated. 

Some vending machines work best with a smart lock because tubular keys operate locks in a certain way.

But that doesn’t mean they are limited to electronic technology. It can also be radio frequency identification technology creating advanced security solutions. 

Another name for these is intelligent keys. They limit the possibility of manipulation and picking because of the smart security system on the vehicle. 

smart key for electronic locks in a vehicle

The key fobs have buttons on them. Some can control access, like unlocking the car, and some can even open the vehicle’s trunk. 

Useful guide: How to Override Function to Remove Key From Ignition?

Mortise Cylinder Keys

Mortise Cylinder Keys are specially designed for mortise cylinder locks. It is a lock used especially indoors. Unlike rim cylinders, these are installed within the door. The cylindrical structure covers the locking mechanism. The key for such locks has specific designs to match the keyway.

Interestingly, Mortise’s Cylinder keys come with many variations. It can have pins, tumblers, and dimples.

Antique Keys

As the name suggests, these keys are beautifully crafted keys you come across. These vintage keys are of aesthetic and cultural value. Skeleton Key is an excellent example.

Antique skeleton keys were made with incredible details for door locks, chests, and vintage drawers. The material for these keys varies from time to time.

Different types of old keys are made of other materials like copper. 

They also have intricate designs with brass, steel, silver, and gold materials. Barrel keys are another example of them, and they are used for tubular pin tumbler locks.

People keep skeleton keys for decoration purposes. They tell the story of their time, and it’s a great way to keep a piece of history in your house. 

a picture of antique keys

Worth reading:

To Wrap it Up

Choose a lock that fits your needs. The way keys have evolved with time shows that humans have updated security systems to cater to different needs. 

One of the many locks will cater to your level of security. Never force different keys into locks that they don’t fit in. Instead, call a locksmith and get the issue sorted


Leave a Comment