What Is A Deadbolt Lock, And Why Should You Install It?

Key Takeaway

  • Deadbolt locks work by pushing a bolt into a door frame that can only be retracted either by a key, thumb-turn or electronically.
  • They provide better security than door knobs that have spring latches.

Deadbolts have become the mainstay of home security over the last few years. More often than not, you will find them on almost everybody’s front door.

But do you know what is a deadbolt and how does it work? what are some of its vulnerabilities? Or what are the different types?

A deadbolt is a locking mechanism that works by pushing (or retracting) a bolt into the doorframe and can only be turned by a key, thumb-turn (or lever) or electronically. They don’t contain spring latch as is found in doorknobs that makes them more immune to loiding.

In this article, we will take a deep dive into the world of deadbolts. We will try to understand intricate details yet keep the language simple. So let’s get straight down to it.

How Does a Deadbolt Work?

Deadbolts are often morticed into the door and works by extending (or retracting) the metal bolt into the strike plate (on doorjamb) with a key, thumb-turn or electronically.

As shown in the video above, the bolt is activated by a touchscreen or a key on the outside and a thumb-turn on the inside.

Deadbolt gets its name because the bolt becomes “dead” when pushed into the strike plate. It can only be operated manually. This is in contrast to door knobs where latches are spring loaded and can be jimmied with a crowbar.

The Important Parts of a Deadbolt (Real Images)

Though there are many small parts of a deadbolt, for the sake of brevity and context, we will keep the list only to the important ones. I will be sharing images of Kwikset Halo that is a smart deadbolt and is installed on my front door.

  • Outer Assembly: Outer assembly is the part of the deadbolt that you see on the outside of the door. This will contain either a keyway or electronic keypad (or touchscreen) to lock and unlock the bolt.
Outer assembly of the Kwikset smart deadbolt that is installed on the front door
  • Inner Assembly: As the name suggests, this is on the inside of the door. More often than not, you will find a thumb-turn to activate the bolt. There are some instances when you might find a keyway as well. More on this later.
Thumb-turn on the interior assembly
  • The Bolt: Bolt is a metal piece that extend from the door into the strike plate. It wouldn’t be wrong to say that the bolt is the star of the deadbolt. They come in various shapes and sizes but the most common shape is a rectangle.
The bolt
  • Strike Plate: It is a metal casing that is affixed on the doorjamb that holds the bolt tight. Without the strike plate, the bolt might damage the wooden frame if enough force is applied.
Strike Plate

How Is Deadbolt More Secure Than a Door Knob?

So now when we have learnt about different parts of a deadbolt and how does it work, let’s understand what makes it more secure than a door knob.

Deeper Bolts

The bolt in deadbolts are longer (around 1 inch as compared to 0.5 inch on doorknobs) and extends farther down the hole on the doorjamb. This helps them withstand larger brute force as compared to door knobs

Loiding Proof

Deadbolt bolts are not spring loaded which makes them immune to bypassing techniques like loiding.

Loiding is a technique where a thin metal sheet like credit card is inserted between the latch and the strike plate, putting enough pressure on the latch so that it retracts. Learn how to do it – picking a lock with a credit card.

Since the bolt in a deadbolt is not spring loaded, putting pressure will not make it retract providing better security than door knobs.

Deadbolt Vulnerabilities

All this while we have only seen positives of a deadbolt but does that mean it doesn’t have any vulnerabilities?

Definitely no! Deadbolts have their fair share of vulnerabilities. Some of them are –

  • Lock Picking: As is the case with any lock, even a deadbolt can be picked with lock picking tools.
  • Bumping: Bumping is way of opening a lock by forcing the bump key violently into the keyway and moving the pins to the sheer line.
  • Impressioning: Impressioning is the technique where a new working key is made for the lock without disassembling or breaking it.
  • Brute Force: It is a known fact that burglars try to force their way through a lock rather than pick them as forcible entry is much easier and quicker than picking the lock. And deadbolts are not immune to brute force being applied on them. However, It is worth noting that their ability to handle brute force is determined by their ANSI lock grade. Higher the ANSI grading, better will be their tolerance.
  • Drilling
  • Snap Guns
  • Brute Force

Even though deadbolts have all these vulnerabilities, they are still the best lock mechanism to protect your front door.

Different Types Of Deadbolt Locks

Different Types Of Deadbolt Locks

Though there are various types of deadbolts and covering them extensively here will not be possible, I am listing the most commonly found ones.

  • Single-Cylinder Deadbolts: These are the most common deadbolts found in households. They have a key on the outside and a thumb-turn on the inside.
  • Double-Cylinder Deadbolts: Comes with 2 cylinders which means that they are operated by keys on both sides of the door. To learn about which one to choose, read my earlier article on Single cylinder vs double cylinder deadbolts.
  • Vertical Deadbolts: The bolt moves in vertical direction instead of horizontal as in standard deadbolts.
  • Rim Deadbolts: Surface-mounted deadbolts that is accessible only on the inside of the door.
  • Electronic Deadbolts: These deadbolts are operated with battery. If an electronic deadbolt connects with wifi and can be operated with a mobile app, then they are called smart deadbolts.

Frequently Asked Questions 

Q1. Can you add a deadbolt to a steel door?

Answer – Yes, you can add a deadbolt lock into a steel door, but the process of drilling is a little different and more complex as you would require to use self-tapping screws. 

While standard screws require a pilot hole to be bored or punched before they can be fitted, the hole is drilled and tapped in one step when using self-tapping screws. I would recommend taking the help of a professional in this case if required.

Q2. Can you put a deadbolt on the bedroom door?

Answer – You can easily install a deadbolt on a bedroom door as you do on an exterior door. However, the interior doors are usually thinner than the exterior doors of the house, so ensure that the deadbolt fits well on your bedroom door before installing.


Deadbolts are one of the simplest and most cost-effective enhancements you can make to the protection of your house or office. Despite the fact that they are not entirely pick-proof, they can guard you against any forced entry and avoid several forms of illegal entry. 

This article must have helped you gain an insight into what deadbolts are and how they work. You can choose from different types of deadbolts depending on your specific requirements. 

If you have more questions about your home’s safety and security, write to me in the comment section.

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Hey! I am Mark. Though I am not a locksmith by profession, but locks have always fascinated me since my teens. And it all started when I got locked out of my house and I had to pick the lock. Since then it has become my hobby to learn more about different kinds of locks, understand their working and methods to pick them up. In due course of time, I have also become better aware of how installing the right lock goes a long way in ensuring iron clad security. I aim to share my passion (about locks) through this blog. If you are also passionate about picking locks or are just looking to beef up the security, hop on the ride.