How to Break a Lock with a Hammer (3 Methods)

You may need to use a hammer if you’ve lost or misplaced your lock key and don’t know how to break in.

I’ve used this method as a handyman and will teach you how to do the same safely in this guide. You might even be able to reuse the lock if all goes well. Applying the right amount of force when tapping can render the lock reusable by minimizing the damage to the pins underneath the lock’s body.

In general, you need to follow these steps to break a lock with a hammer:

  • Fetch a bump, mallet, or a ball-peen hammer.
  • Put on your safety gear and gloves.
  • Pull the hammer shackle by inserting your fingers while avoiding the lock’s body.
  • Insert a bump key if it’s a mounted or cam lock.
  • Tap the lock’s side (or bump key) repeatedly with a hammer to disengage the pins underneath.
  • Keep tapping the lock until it opens.

My guide below will cover the procedure in more detail for 3 scenarios. Let’s begin.

Breaking a Lock with a Hammer (3 Methods)

We will focus on 3 methods to show how to use a (non-regular) hammer to break 2 types of locks: a padlock, when detached and attached, and a mounted or cam lock.

However, you can use tools like wrenches and screwdrivers for the same purpose. Follow the steps below to break a lock with a hammer without fuss.

The Things You’ll Need

You will need the following 3 items:

  • A bump hammer, mallet, or ball peen hammer (not a regular type)
  • Safety gloves

A Non-Regular Hammer

You have 3 options for using a hammer, which must not be a regular one to minimize damaging the lock:

  • A bump hammer is designed to bump a lock. It is made of a high-density polymer with a rubber handle. It enforces proportional pressure on the lock and exerts a sharp impact, which is key to ramping it. If you can’t find a bump hammer, use a mallet instead.
  • A mallet is a special hammer with a soft head that pounds objects lightly without inflicting undesirable damage. Mallets ensure an easier and more strategic aim when striking a lock. Mallet hammers are made of wood, rubber, soft metals, plastic, or rawhide.
  • Use a ball-peen hammer if you can’t access a mallet or bump hammer. It has two hammerheads: a regular-shaped one and a round hammerhead. Use a size appropriate for the size of your lock. A size 4 ball-peen hammer is usually right for a small lock.

Three different type of hammers

Other Requirements

You will need a bump key and a rebound ring for the 3rd method to open a mounted or cam lock.

Safety Gloves

Wear safety gloves with thick fabric (or hammer-proof gloves) to protect your hand from stray hammering.

They are reinforced with a thermoplastic layer that sucks up the pressure of a stray hammering. But be extra cautious because only the fingers are safe; the palm is still vulnerable.

A variety of hammer-proof gloves are available, including leather and Kevlar gloves. I prefer leather gloves to Kevlar because they provide a firmer grip. However, Kevlar gloves are thicker and can thwart abrasions and cuts. Importantly, ensure your hands fit inside the gloves.

Using a Hammer to Break a Detached Padlock (2 Steps)

Use this method if the padlock is not attached to anything, and you can hold it easily in one hand.

Step 1: Hold the Lock

Hold the detached padlock in one hand and the hammer in the other, as shown below.

A person is holding a metal lock
Video | BosnianBill

Step 2: Tap Lightly

Tap rapidly but lightly on one side of the lock with the hammer.

A person is using a hammer to open the metal lock
Video | BosnianBill

The lock should open after a few taps.

A person is holding a padlock
Video | BosnianBill

Using a Hammer to Break an Attached Padlock (3 Steps)

Use this method if the padlock is attached to something.

Step 1: Preparations

Gather the necessary tools for the task — a hammer and safety gear.

If not careful, you could sustain two potential injuries in this activity: the impact of the flying objects on your eyes and that of a stray hammer on your hand. So, have your safety gear on before proceeding.

Step 2: Pull Up the Lock’s Shackle With a Hammer

Insert any two fingers you’re comfortable with into the shackle loop and force the shackle from the top of the lock. The locking pins (inside the lock) align themselves well, making the crack job easier.

Alternatively, you can place a crowbar on top of the lock and unleash brute force on the crowbar with a hammer until the lock flings open. Eliminate all slack or leeway in the shackle. Otherwise, the lock won’t break easily, no matter how strongly you knock it. Avoid grabbing the lock’s body section to get a space for the hammer.

crowbar on top of the lock
Video | BosnianBill

Step 3: Tap the Lock’s Side Repeatedly

Now, target the fixed end of the shackle’s side, where the pin is on the inside.

Pound the lock multiple times with quick and short strikes. This action disengages enough pins to bump the lock open.

Resist the temptation to swing for the fences. The pins must constantly move or disengage to override the lock, not brute pressure. Teeing up can only harm you.

Using a Hammer to Break a Mounted or Cam Lock (3 Steps)

Use this method if the lock is a mounted or cam-type, whether attached or not.

Step 1: Insert a Lockpicker or Bump Key

Insert a lockpicker or bump key into the key slot.

Then, put a rubber rebound ring over it, shown in green in the picture below. It will help in striking the lock’s face and bump it quickly.

Step 2: Use a Small Tension Wrench

Put a small tension wrench in the key’s bow.

Step 3: Tap Lightly

Tap lightly with a bump or other non-regular hammer.

Keep tapping until the lock opens.

Repurposing a Forcefully-Opened Lock

Depending on the lock’s condition after forcefully opening it, you can repurpose or reuse it.

You can reuse the lock if it is still usable — if the pins inside the lock are still intact; however, fasten it well first. Otherwise, discard it in a scrap collection for a few dollars.


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About Sam Orlovsky

AvatarCertifications: B.E.E.
Education: University Of Denver - Electric Engineering
Lives In: Denver Colorado

Electrical engineering is my passion, and I’ve been in the industry for over 20 years. This gives me a unique ability to give you expert home improvement and DIY recommendations. I’m not only an electrician, but I also like machinery and anything to do with carpentry. One of my career paths started as a general handyman, so I also have a lot of experience with home improvement I love to share.

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