What Is a Deadbolt Lock and Why You Should Use One

Deadbolts are the bread and butter of home security and are a cheap and effective way to improve the resilience of your doors.

But what is a deadbolt lock, how do they work, and why exactly should we use them?

A deadbolt is a locking mechanism that pushes a bolt into the doorframe and is activated using a key, thumb-turn, or electronically. Deadbolts add another layer of security and make a door more resilient to brute force attacks.

Now that's the short answer. Let's break the deadbolt lock down a little more so that you can utilize this amazing device to its full potential and make your doors iron-clad!

How Do Deadbolts Work?

Deadbolts work by forcing a hardened metal bolt into a doorframe reinforced with a metal "strike plate."

This bolt is considered "dead" because it can not be retracted from the doorframe without manually actuating the locking mechanism using a key, a thumb-turn, or electronically (such as smart and keyless locks).

There are three main advantages to using a deadbolt.

1. Deadbolts must be mechanically activated—unlike a spring-latch used in doorknobs that can be loided (jimmied) using credit cards, knives, or professional tools such as latch slips.
2. The bolt extends deep into the doorframe—making it more resilient against forced entry—such as kick-ins.
3. They are easy to use—which means they will be used more often.

In a nutshell, a good deadbolt can protect your doors against quick access techniques, such as loiding, and can extend the time it takes to kick in your door.

The Main Parts of a Deadbolt

There are a lot of nitty-gritty parts to the deadbolt—most of which you'll never need to know.

However, there are four main parts worth understanding:

1. Bolt: The section that extrudes from the lock into the doorframe. They vary in material, size, shape, and length—depending on the quality of your lock.
2. Outer Trim: The section on the outside of the door that uses a keyed-lock cylinder to actuate the bolt.
3. Inner Trim: The section inside your home that is activated using a thumb turn. On some occasions, the inner trim can also use a key cylinder and requires a key on both sides of the door.
4. Strike Plate: Used to re-enforce the section of the door in which the bolt sits. Without the strike plate, the bolt can easily rip through the wooden frame if adequate force is applied.

This is a mile-high description of the parts of a deadbolt and only includes the main parts. If you would like a deeper dive, including other internal components, check out my guide on the parts of a deadbolt.

Can You Pick a Deadbolt?

Do you still need to worry about lock pickers if you install a deadbolt?

Deadbolts can be picked using lock picking tools and bypassed using other common lock manipulation tactics like bump keys, snap guns, Lishi picks, and impressioning.

However, lock picking is not the problem that deadbolts solve, and the truth is that most thieves do not pick locks; they break them.

Let's look at a little data.

In 2019, 55.7% of burglaries involved forcible entry. In 2010 the U.S. Justice Department released a report that determined only 1.3% of locks were unlawfully bypassed using any lock manipulation technique such as lock picking, shimming, bumping, impressioning, or others. This figure also included lock manipulation of windows and sliding doors, not just front doors.

Check out my article Why Burglars Don't Pick Locks for a breakdown of the numbers and all the sources.

The reality is, most thieves and low lives don't pick locks for three main reasons:

1. Lock picking can be slow and unpredictable—there are so many variables that can affect how long it takes to get through a lock.
2. Burglars seek the smallest risk—which can mean finding either an unlocked door or one that is weak enough to kick down quickly.
3. Professional lock pick tools are a dead giveaway for malicious intent—burglars don't want to be caught with anything that might incriminate them.

Oddly enough, the most commonly used tools of a thief are screwdrivers, crowbars, and hammers. 99.9% of lock pickers are hobbyists and not out to steal your stuff.

But this doesn't mean that malicious lock picking isn't a problem to worry about. You should still do everything to protect your locks against lock picking techniques.

Use high-quality locks and never rely on one thing to protect you. Layer your security using different methods such as:

• Alarms
• Night latches
• Cameras
• Signs
• A dog

You don't need to make your home impenetrable to make it safe. Instead, you just need to make it too annoying and risky for anyone to try. The more time it takes for a burglar to break in, the higher the chance they get caught.

Burglars seek the smallest risk—the path of least resistance.

But most importantly, use your locks. An astonishing 39.5% of non-forced entries are simply because a burglar could walk up and open the front door or find an unlocked window. Security is only secure if you use it.

Other Vulnerabilities

In addition to lock picking, deadbolts have other vulnerabilities, such as:

• Lock Bumping
• Impressioning
• Snap Guns
• Lishi Keys
• Drilling
• Ice Pick Attack
• Weak Door or Door Frame
• Improper Installation

If this seems like a lot of vulnerabilities, you are correct. Remember, deadbolts are not foolproof, and there is no such thing as an "unpickable lock."

When looking to replace a deadbolt, you should strive to find one that provides "resistance" against many of these attacks. For example, the best deadbolt locks will utilize a hardened plate or install ball bearings in front of vulnerable areas (shear line or mounting screws) to protect against drilling attacks.

But the most important thing that you can do is install it correctly. Many people throw away the strike plates or install them wrong, and as a result, the door buckles under the first kick. Always use the strike plate and install it with 3" to 4" hardened screws.

If you want to take it to the next level, consider looking at a high-security front door lock that provides extra resistance to manipulation.

Deadbolt Types

The deadbolt can come in many forms, but they all fall under five main types.

1. The Single-Cylinder: Keyed on the exterior side, thumb turn on the interior side
2. The Double-Cylinder: Keyed on both sides of the door
3. Keyless Deadbolt: Programmable electronic locks such as keypad locks and smart locks
4. Vertical Deadbolt: The bolt moves up and down instead of horizontally
5. Rim Deadbolt: Is only accessible on the interior side of the door

If you would like to learn more about the different types of deadbolts and how they compare to other common types of door locks, check out my comprehensive guide on the types of deadbolts.

Final Thoughts

When properly installed, deadbolts are one of the cheapest and most effective additions you can make to the security of your home. While not perfect, they can statistically protect you from the most common type of unlawful home entry—brute force.

That being said, the deadbolts are not foolproof. They are essentially worthless when installed on cheap doors or weak doorframes and can fall quickly to many lock manipulation techniques—such as lock picking.

For this reason, you should not rely on a deadbolt alone and layer your security. Use a deadbolt to protect your doors against kick-ins while using other methods to protect against other types of bypasses.

I hope this guide helped you better understand the true purpose of a deadbolt and why you should use one. They really are important devices to help safeguard the things we love most.