Bump Keys: The Secret Weapon Of Locksmiths And Criminals Alike

Key Takeaway

  • A bump key is a specially designed key that can be used to pick a lock by inserting the key and tapping it with a blunt object, causing the pins inside the lock to jump and allowing the lock to be turned
  • While bump keys were originally developed for use by locksmiths, they have been adopted by criminals as a means of gaining unauthorized access to buildings and vehicles.
  • To protect yourself from bump key attacks, it’s important to take security measures such as installing high-security locks, using lock-bumping protection devices, and being vigilant about the security of your property.

As we go about our daily lives, we tend to take security for granted. We lock our doors, secure our windows, and think that we’re safe from intruders. However, what many people don’t realize is that some locks are more vulnerable than others, and there are techniques that criminals can use to bypass even the most sophisticated security systems. In fact, according to the FBI, you can expect 1 out of every 36 homes to be robbed at some point or the other. (source)

One such technique is lock bumping, which involves using a bump key to open a lock without a key. Lock bumping is a technique that locksmiths have used for many years to open locks quickly and efficiently. However, in recent years, this technique has also been used by criminals to gain access to homes and businesses. At the heart of lock bumping is the bump key – a specially crafted key that can be used to open many types of locks without the need for picking or drilling.

Being a lock picking enthusiast, I shall help you take a deep dive into bump keys, exploring what they are, how they work, and tips to protect yourself from this type of attack.

What Is A Bump Key?

A bump key is a specially designed key that can be used to pick a pin-tumbler lock. It is typically made by filing down a regular key to create a series of “teeth” that are all the maximum depth allowed by the lock.

What Is A Bump Key?

When inserted into the lock, the user applies pressure to the key while “bumping” it, causing the pins to jump above the shear line momentarily and allowing the lock to be opened. Bump keys are often used by locksmiths and law enforcement agencies but can also be used by burglars and other criminals to gain access to locked buildings or vehicles.

What Is A Bump Key?

It is important to note that bump keys are not legal in some jurisdictions, like Ohio, Virginia, and Nevada, and their use could result in criminal charges. 

Is Lock Bumping A Security Threat?

Yes, lock bumping can be considered a security threat because it can be used to open many types of locks quickly and without the need for specialized knowledge or tools. Lock bumping is a relatively simple technique that can be learned by anyone easily. On top of that, bump keys can be easily found online, making them a real threat to security.

While not all locks can be bumped, many common household locks, padlocks, and commercial locks are vulnerable to bumping. It’s important to be aware of the risks of lock bumping and take steps to secure your property and belongings accordingly.

Principle Of Using Lock Bumping Key

A bump key works by using the principle of Newton’s Third Law of Motion, which states that for every action, there is an equal and opposite reaction.

Principle Of Using Lock Bumping Key

Similarly, when a bump key is struck with a hard object, such as a hammer or screwdriver handle, the force of the impact causes the pins inside the lock to jump above the shear line.

Principle Of Using Lock Bumping Key

As mentioned above the bump key is designed in such a way that the teeth of the key are cut to the maximum depth allowed by the lock. When inserted into the lock, the teeth push up the pins inside the lock, preventing the lock from turning. However, by applying pressure and then bumping the key with a hard object, causes the key to push all  the pins up even further creating a gap between the pins and the shear line.

This gap allows the key to turn and unlock the lock. The process is quick and relatively easy hence bump keys have become a popular tool for both legitimate and illegitimate purposes.

How To Use A Bump Key?

How To Use A Bump Key?

Using the technique of bumping keys to open locks can be illegal and also not recommended without proper training and authorization. However, if you are a licensed locksmith or have the legal right to use bump keys, here are the general steps for using a bump key:

  • Step 1: Obtain a bump key that is designed for the specific type of lock you want to open.
  • Step 2: Insert the bump key into the lock all the way.
  • Step 3: Apply a slight amount of pressure to the key to keep it in place.
  • Step 4: Use a hard object, such as a hammer or screwdriver handle, to “bump” the end of the key while still applying pressure.
  • Step 5: The pins inside the lock will briefly jump above the shear line, allowing the lock to turn and open.

How To Prevent Lock Bumping?

There are several ways to prevent lock bumping and make your locks more resistant to this type of attack. Here are some of the most effective methods:

  1. Install High-Security Locks: High-security locks are designed to be more resistant to bumping, picking, and other forms of lock manipulation. Look for locks that have anti-bump pins, side pins, and mushroom pins, as well as locks that are made of strong materials, such as steel or brass.
  1. Use Lock Bumping Protection Devices: There are several types of devices that can be installed on your lock to make it more resistant to the bumping procedure. These include anti-bump pins, which are designed to prevent the pins from jumping above the shear line, and cylinders that are specifically designed to resist bumping.
  1. Upgrade Your Locks: If you have older locks, they may be more vulnerable to bumping. Consider upgrading to newer, more secure locks that are designed to be bump-resistant and don’t rely on the pin tumbler locking mechanisms.
  1. Use Electronic Locks: Electronic locks, such as keypad locks or smart locks, are not susceptible to bumping, as they do not use traditional keys. These locks are becoming popular and can be a great way to enhance the security of your home or business.
  1. Keep your locks well-maintained: A poorly maintained lock is more vulnerable to bumping because its internal pins and springs may become worn, damaged, or misaligned over time. Regularly lubricate your locks and replace worn-out parts to ensure that they are functioning at their best. In a well-maintained lock, the internal pins and springs are properly aligned, making it more difficult for a bump key to cause the pins to jump.
  1. Install security systems like CCTV cameras and alarms: Installing security systems like alarms and CCTV cameras can enhance the security of a house in several ways. Security systems can detect and alert homeowners to potential security breaches. Alarms can be set to go off if a door or window is opened without authorization, and CCTV cameras can capture footage of any suspicious activity. The presence of security systems can also deter potential intruders from attempting to break in. This is because burglars are more likely to target homes that they perceive to be easy targets.

Frequently Asked Questions

Q1. What are the different signs that your lock may have been attempted to be bumped?

Answer. There are several signs that your lock may have been attempted to be bumped, including scratches around the keyhole, a misaligned keyhole, difficulty turning the lock, and loose or damaged lock components. 

If you notice any of these signs or suspect that your lock may have been attempted to be bumped, it is important to contact a licensed locksmith to inspect and rekey the lock as soon as possible. You may read more about what to do if your lock has been tampered with in one of my previous articles.

Q2. Can all locks be bumped?

Answer – No, you can’t bump all locks. Some locks are designed to be more resistant to bumping than others, such as high-security locks and deadbolts. 

A deadbolt typically has a solid metal bolt that extends deep into the door frame, making it more difficult to bypass the lock by bumping. Additionally, many high-security locks have special features like anti-bump pins that make them more resistant to bumping.

However, many common household locks and padlocks are vulnerable to bumping.

Q3. Can lock-bumping cause damage to the lock?

Answer – Yes, bumping a lock can cause damage to the lock, making it more difficult to open or requiring it to be replaced entirely.


Bump keys represent a serious security threat that is often overlooked. While they were originally developed as a tool for locksmiths, they have been adopted by criminals to gain unauthorized access to buildings and vehicles. The ease with which a bump key can open a lock is genuinely alarming, and people must take steps to protect themselves from this type of attack. 

By understanding how bump keys work and implementing security measures such as installing high-security locks or using lock-bumping protection devices, you can significantly reduce the risk of becoming a victim of lock bumping. 

If you found the information given in the article helpful, share it with your friends and family. It’s always better to be proactive when it comes to security, and by taking action now, you can help ensure the safety of your property and loved ones for years to come.

Leave a Comment

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.