How to Cut a Lock

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Have you found yourself locked out? You put that padlock on there to keep others out but now you can’t find the key, or maybe you misplaced the combination. Truly, it happens to the best of us. What do you do when you get locked out? You cut the lock!

In this guide, we will show you how to cut a lock and walk you step-by-step through the process.

Prepare for the Task

You will need some tools in order to be able to cut a lock. The good news is that there are several different tools you might be able to use. If you have just one of the potential tools we recommend, you are good to go.

If you have nothing at all that falls into the list, you may need to consider buying something. You don’t have to go spend a bunch of money so if you do need to buy, just find the most convenient and affordable option to help you out.

Locked door

Here is the list of tools that we recommend. You don’t need all of these, just one will do.

  • Bolt Cutter (this is our recommendation if you have it)
  • Angle Grinder: be sure you have a cutoff wheel attachment if you opt to use an angle grinder
  • Dremel Tool: You will need a cutoff wheel attachment to use with a dremel
  • Cutting Torch: If you have a cutting torch or a plasma cutter, these make quick work
  • Hacksaw & Propane Torch: A hacksaw works best if you also have a propane torch to heat the metal of the lock.

In addition to one of these tool options, we also recommend having safety goggles as well as work gloves to keep you safe while you work.

For the most part, cutting a lock will be fairly simple if you follow the right steps to do so.

Since you can use any of these tools, we will walk you through how to cut a lock with each of them so you know exactly how to use whichever one is available to you.

Cutting a Lock with Bolt Cutters

Bolt cutters are perhaps the easiest thing to cut a lock with because they are designed for just such a task. If you have bolt cutters, then you need to look no further than this part of the instructions to cut your lock. This is one of the most popular solutions and that is because they are simple and effective.

Bolt cutters look like large pliers and they work like scissors on a lock. We recommend bolt cutters that have a long handle as this just makes it easy to get the leverage and strength you might need behind the cut.

The key for bolt cutters to work on a lock is they have to be a heavy-duty pair. So, while you may have been excited that you have bolt cutters for the task, if they aren’t heavy-duty bolt cutters, you will need to try one of the other options here.

If you have heavy-duty bolt cutters with long handles, you should be able to place them on the lock. You will need some strength and leverage, so keep that in mind as you make your cut.

Cutting a Lock Using an Angle Grinder

If you have an angle grinder with a cutoff wheel, this is another simple way to cut your lock. Angle grinders can get loud so you may want some earplugs in addition to your gloves and safety goggles for this one.

Before you get started, make sure you have the correct disc for cutting a metal lock. As mentioned earlier, we recommend using a cutoff wheel attachment, and you can change out the wheel on your angle grinder following these instructions.

Here are some steps for cutting a lock using an angle grinder.

  1. Safety Gear: You will need to put on your safety gear. We recommend eye goggles and work gloves. Since angle grinders can be noisy, you might also want some earplugs. The earplugs are optional but with the noise, you won’t regret them.
  2. Line Up the Grinder: Line up your grinder so that it is at a perpendicular angle to your lock. It is the blade that should be perpendicular before you start cutting.
  3. Make the Cut: Once you line up the blade properly, you should be able to use the angle grinder to slowly cut through the lock. You will want to let the tool move slowly. There is no need to apply extra pressure.
  4. Cut the Other Side if Needed: If you are unable to work the lock free from cutting just one side of the lock, you can use the exact same steps to cut through the other side of the lock and get it to come free.

Don’t forget to keep your movements slow. While you will need to exert a bit of pressure, you should let your angle grinder do most of the work for you.

It will move slowly but as long as it is moving, just be patient and let the grinder do its job. If you get one of the best angle grinders, it should make very short work of your lock.

Cutting a Lock with a Dremel Tool

Another handy way to cut a lock is to use a dremel tool. With a dremel, you will need a cutoff wheel, which is quite similar to that of an angle grinder.

The best dremel tool usually is smaller than an angle grinder. In fact, you might find that a dremel tool is easier to use, especially if the space to cut the lock is tight in any way. The small tool is easier to move around and place as needed to make the cut.

Here are steps for cutting a lock with a dremel tool. You will notice these steps are very similar to the steps for an angle grinder.

Dremel
  1. Safety Gear: Before you start, make sure you put on your safety gear. Dremel tools are not as loud as angle grinders so you don’t necessarily need earplugs. However, you should plan to wear safety goggles and work gloves for your protection.
  2. Line up the Dremel: Line up your dremel to prepare to start your cut. The cutoff wheel needs to be held at a perpendicular angle to the lock, much like what we discussed with the angle grinder.
  3. Make the Cut: Now, you are ready to start cutting with the dremel tool. Keep your angle steady and let the dremel do the work. You may need to exert some natural pressure but don’t press too hard. The dremel will move as it cuts.
  4. Cut the Other Side if Needed: Much like what we saw with the angle grinder, you might be able to work the lock off after just cutting one side. However, if you can’t get it off, you can cut the other side of the lock using the exact same methods.

If you’re considering picking up a dremel, read our reviews on the 3000 vs 4000 model and the 4000 vs 4300 model.

Cutting a Lock with a Cutting Torch

Not everyone has a cutting torch or a plasma cutter and that is ok. However, if you do have either of these tools, they will make quick work of cutting through a lock.

An A/O torch is the fastest possible way to cut a lock. While locks are strong and sturdy, they simply can’t stand up to a cutting torch that is designed to defeat materials like what a lock is made of.

Like we said, don’t go out and buy a torch just to cut off a lock. Some people would actually say this is far more power than you need. However, we feel like if you have this tool at your disposal, why not put it to use? We’ve use it to cut a lock, and its very simple.

If you are using a cutting torch, you can follow these steps.

  1. Open Oxygen: Start by opening your oxygen tank all the way. Turn your acetylene approximately a quarter turn to 5-6 PSI. You will then set your oxygen PSI around 45-50.
  2. Spark Your Torch: Spark the torch when you have the oxygen and acetylene set properly. Adjust the acetylene after the torch is sparked, reducing until there is no more black smoke. Follow up by then adjusting the oxygen so that your flame turns to a white cone.
  3. Make the Cut: Once you have your settings and flame ready, use the flame to cut through the lock. You might want to focus the flame on the lock for just a moment to heat it up first. Then, you can simply move the flame back and forth in a cutting motion until the lock gives and you have cut through it.

Cutting a Lock with a Hacksaw & Propane Torch

Our final method is to use a propane torch and a hacksaw. This is probably the last resort to be used if you have nothing else at your disposal. It takes the longest and isn’t always easy to do.

To use this method, you will first use the propane torch to heat up the lock. This weakens the steel. Heat it until it glows. You will then need to let the lock cool after turning off the heat. Use the hacksaw to cut through the spot that you heated.

Heating and cooling takes several minutes but once you start cutting, the cut itself will only take 1-2 minutes most likely.

Summary

Cutting a lock can be done in many different ways. Any of these methods will work for you if you have the tools available to try them out. Remember to always practice safety and follow the proper steps to avoid damaging your tools or the surrounding areas.

An expert at home repair, remodel, and DIY projects for nearly 40 years. His first experience came in completely restoring an antique home. Completely redone from the inside out, and restored to its original form, the home is a featured design by renowned Southern California Architect Cliff May, considered to be the father of the California Ranch Home. Now Dennis spends his time on fine woodworking projects and tool comparisons.