Locked Out? Here’s How to Cut Off a Lock

Getting locked out happens to the best of us. Maybe your lock rusted shut, or you’ve lost your keys. Maybe you’ve just purchased a storage locker at auction, and now you need to cut the old lock off.

In any event, the question of how to cut off a lock is fairly easy to answer, and today we’ll cover a bunch of different ways you can get the job done, quickly and easily.

What You’ll Need

There are several different tools you can use to get the job done. Chances are, you have at least one of these tools in your arsenal already. If that’s the case, stick with what you have. You can learn how to cut off a lock using any of the tools below:

Beyond one of the tools above, all you’ll need is some safety equipment to protect yourself from sparks and metal shavings:

Using Bolt cutters

Bolt cutters are one of the most effective and popular ways to cut through a lock. Essentially, bolt cutters are just a bit pair of scissors that are equipped with a fulcrum joint which allows them to transfer much more power to the blades, allowing you to cut through thick metals.

Bolt cutters with long handles provide the most leverage and make it easy to cut through thicker, harder metals. Meanwhile, bolt cutters with shorter handles may not be able to cut through a heavy-duty lock. If you don’t have a heavy-duty pair, move on to one of our other methods.

Using an Angle Grinder

An angle grinder with a metal cutoff wheel can make quick work of cutting through a lock.

First, put on your safety goggles and work gloves as you’ll be dealing with metal shavings and sparks. You may also want to consider wearing earplugs as well.

You want to hold the angle grinder, so the blade is perpendicular to the lock. Then, slowly and deliberately begin cutting. Don’t apply too much pressure; the tool will do all the work for you.

Once you’ve cut through that side of the lock, you should be able to work the lock free. If that's not an option, cut the other side of the lock as well.

Using a Dremel

A Dremel with a cutoff wheel follows the same premise as an angle grinder does. Since a Dremel is smaller, they can be particularly helpful for use in tight quarters since they’re easier to maneuver.

Take extra care when cutting with a Dremel and use a reinforced cutoff wheel wherever possible to limit the chance of the wheel breaking as you cut.

Using a Cutting Torch

Using a A/O torch is probably the quickest way to cut through a lock since the lock is no match for the power of a torch. This method may be overkill, but if you happen to have a torch handy, this is a great way to make use of it!

First, open your oxygen tank all the way and your acetylene tank about a quarter turn. Set the PSI for the oxygen tank at about 45-50 PSI and the acetylene at about 5-6 PSI. Next, turn the oxygen valve on your torch all the way up and turn the acetylene valve slightly.

Now, you can spark your torch. Adjust the acetylene valve until the torch is no longer producing thick black smoke. Now, adjust the oxygen valve until the flame becomes a focused, white cone of heat. You’re ready to cut the lock.

Before you begin your actual cutting motion, it can be helpful to preheat the lock. Once you’re ready to cut, move the flame slowly and deliberately across the shackle of the lock until you’ve cut all the way through.

Using a Hacksaw & Propane Torch

This method is a bit more time consuming and impractical. But if you don’t have bolt cutters or other cutting tools, this method may be your best bet.

The shackle of most locks is made from hardened steel, and a hacksaw blade is no match for it. But, if you heat the shackle up before cutting it with the hacksaw, you’re able to weaken the steel to the point where it’s easy to cut.

First, turn your propane torch on, and begin to heat the area of the shackle where you plan to cut. Continue to heat that area until it begins to glow from the heat. Once it’s glowing, shut your torch off and allow the lock to cool.

Once it’s cool, you’ll be able to cut through the shackle with a simple hacksaw in about a minute flat.

Final Word

When it comes to how to cut off a lock, there are multiple routes we can take that will all lead us to the same destination. Whether you’re using bolt cutters, an angle grinder or Dremel, a cutting torch or even a hacksaw, be sure to work slowly, carefully and safely. Follow these tips, and you’ll have your lock cut off in no time!

About Gus Donaldson

I built houses for over 30 years and recently retired. I've made lots of mistakes and hopefully teach you not to make the same ones. I still love to build and have a garage workshop that I use for hobby projects like the walnut bookshelf I made for my wife. I like to write and let people know that working with your hands and tools does not need to be intimidating.

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