A key that has broken off inside your door lock can be irritating as well as inconvenient. However, such cases are not uncommon and lucky for you, it's easy to get it out if you use the right tools and follow the right procedures. Here are a few guidelines to help you through this simple task.
Step #1: Don't Try Using the Key Again
This is a precautionary measure that you need to consider. Don't try using the rest of the key to open the lock by fixing it on the part that's already inside the lock. This is a bad idea because you might end up pushing the broken further into the lock, making it even more difficult to remove. Most of the methods of removing the broken part of the key out your door lock will work much easier the shallower the key blade is inserted into the lock.
Step# 2: Apply a Lubricant into the Keyhole
Find a graphite-based lubricant spray or penetrating oil from your local hardware or home improvement store. The lubricant may not be necessary but will help loosen up the works. It is usually very helpful especially if handling the door lock had recently been difficult.
Step #3: Look At How Much Of the Broken Key You Have In Your Hand
Finding out how much of the key broke off the lock will give you a hint of how best to remove it. For instance, if part of the key that broke off includes some of the key cuts, your lock could still be aligned to let the key slide in and out. On the other hand, if you only have the head of the key, you might have already turned the key before it broke. In such a case, you will need to insert a screwdriver into the door lock to turn the key to its vertical position before proceeding to the next step.
Step #4: Remove the Key
Insert the tip of a pair of metallic hair clips or needle-nosed pliers into the keyhole. There are high chances of this method working if all the key cuts are inside the keyhole. This will mean that you will find a grip more easily. You can simply pull out the rest of the key when you find this grip.
If the pliers and clips don't work, try using a jig saw or scroll saw. Insert the blade of the saw into keyhole. Make sure the teeth point downwards. Push the blade down until you feel the blade's teeth grabbing the key cuts. You should then pull out the blade to remove the broken key.
Remember that while you can save some money by doing this on your own, it's always a good idea to call a locksmith.
