How to Get a Broken Key from a Lock

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Losing a key is frustrating enough, but breaking one in the door is next level. Not only is it panic-inducing, it can also be an expensive mistake if you have to completely replace the lock. While it’s tempting—and in some cases, totally justified—to force your way in, that can mean that you’re gearing yourself up for a large bill from a locksmith. The good news? There are some tricks you can try before you need to call a pro.

Here, tips from two lock experts with different skill sets share some tips on the best way to retrieve a broken key. Certified master locksmith and North East Director of Associated Locksmiths of America Bill Mandlebaum has many years of experience helping people during a lock emergency. Security anthropologist and international speed lock-picking champion, Schuyler Towne, can pick a lock blindfold and underwater, has a whole host of tips for “keyhole surgery.” Together, they explain what to do—and what not to do—if you find your key’s broken off inside your lock.

What not to do if your key breaks in the lock

According to Bill Mandlebaum, the best way to ruin a lock is to put glue on one piece of the broken key and then reinsert it into the lock believing it will bond with the other piece. “Every locksmith has seen this multiple times, and all it does is bond to the lock. Then you have no option but to drill it out and replace it,” Mandlebaum says. That’s expensive, and probably avoidable. 

First, identify what kind of key you’re working with

If the key is an old-fashioned bit key, the ones with a flag at one end and a long barrel, then, Mandlebaum says, the flag has probably broken off and a professional will have to take apart the lock to retrieve it. Unless you live in a haunted mansion, you should probably upgrade your security anyway. 

Modern cylinder keys, on the other hand, can be maneuvered out with a little skill and a steady hand. If the key is aligned vertically in the lock, the tumblers (or pins) that the cuts on the key manipulate should not be engaged. If you follow these steps, you should be able to slide the key out.

Note: Unless you are competitive lock picker like Towne, you probably don’t have a set of lock picking tools. However, there are several everyday items that you might carry with you, or be able to borrow from a neighbor, that both Towne and Mandlebaum say will work if you have the patience to use them. 

1. Examine the lock

If the key broke at an angle, take a small flathead screwdriver or a hair pin with the rounded plastic ends broken off, and slide it into the keyway (keyhole) to nudge the key upright. 

2. Use a tool to grab the broken key

Find something small enough to insert into the keyway that will catch hold of the broken key. Mandlebaum recommends using a fishing hook—but if you don’t know anyone with fishing tackle, Towne says bending the tip of a needle so it has a barb on one end will work the same way. Once you’ve “caught” your key, pull it straight out; don’t angle it up or down, as it could catch on the pins. Make sure your fingers are dry, so they don’t slip off the needle or hook, or wear a rubber glove if you have one to get a better grip.

3. Pull the key the rest of the way out with pliers

Pull the broken key towards you as far as you can using this method, then use pliers to pull it from the lock. Mandlebaum says nail clippers or tweezers will grab it just as well in a pinch.

If the key is sticking, try crushing a tiny piece of pencil graphite onto a piece of paper and blowing it into the lock to smooth the way. Never use petroleum-based oil as a lubricant, which will just collect dust and gunk up your lock.

What to do if it’s an emergency

Towne recommends calling a locksmith immediately so one is on the way, and then looking to see how far the key turned before it broke. “Just because the key is broken doesn’t mean it won’t work,” he says. If the key turned a little bit in the lock before it broke, you may be able to turn it all the way to open the door. Towne suggests using the key part in your hand to push the broken key all the way in to engage all the pins; you may feel a click when it is in position. Then, using a flathead screwdriver or other flat piece of metal, twist it in the direction it usually turns. A key needs to rotate in the lock between 90 and 100 degrees for a latch, and a bit more than that for a deadbolt. 

This method means sacrificing the entire lock, because once the key is turned it won’t come out—but if you left something flammable on the stove or have some other emergency that necessitates getting inside as quickly as possible, it might be worth it.

What to do if the lock is frozen

Rain sometimes gets into front door locks and can freeze in low temperatures. Ice in the lock will make it harder to turn a key and therefore easier to break it. If this happens, use a hair dryer to melt the ice and dry the remaining water. If you don’t have a hair dryer, Mandlebaum has used a car cigarette lighter by holding it so it touches and heats the metal lock. 

What to do if you have to call a locksmith

If you are able to get the broken key out yourself, don’t discard it. Mandlebaum says a good locksmith can use a broken key to make a new one. If you need a locksmith to help you after hours, Towne recommends using one who has a portable key punching machine so that once they’ve removed the broken key they can clip a new one to open the door—it will be cheaper than drilling out the whole lock and replacing it.