A key breaking off inside the lock will definitely be an inconvenience because you simply might have locked yourself in or out. Keys can break off inside the lock if you are in a hurry, due to wear and tear, or if the lock has a problem. Whatever the cause, knowing what to do next in terms of a resolution is important. Usually, you will want a professional to handle the case, especially if you have a valuable lock. However, there are some cases where you can remove the key on your own. Here is a look at a few things you can do in such a case.
Don't Enter the Rest of the Key
Perhaps your first instinct would be to try using the remaining part of the key on the lock. This could actually cause more harm than good. By inserting the part you have in your hand in the lock, you risk pushing the part that broke off inside even further, which means you will be making it harder to deal with. You don't need to use the rest of the key, but you shouldn't throw it away. If you are successful removing the broken key from inside the lock, your local locksmith should be able to cut a new key for you from both pieces.
Look at How Much of the Key Broke Off
This will determine your next course of action in removing the key. If part of the key is sticking out of your lock, you may be able to grab it with your fingers and remove it. If you can't pinch the key but part of it is still sticking out, a pair of pliers (needle-nosed) should help. There are high chances of you being able to grip and pull out the broken key more easily if the portion that broke off inside contains all the key cuts.
If the key isn't sticking out at all, you can try using a jig saw or scroll saw. Simply slide it into your keyhole until it grabs one of the key cuts. You can then easily pull it out. However, remember that if the key broke off between the lock and unlock position, you need to twist it to either position before you withdraw it. Before you use your saw or pair of pliers, consider spraying some penetrating oil into the keyway. Lubricating your keyhole will make it easier for you to remove the key.