WD-40 is generally a great product to have on hand whenever there’s an immediate need for an all-purpose lubricant, although it will eventually dry out and need to be reapplied. Avoid using any lubricants that aren’t appropriate for home improvement use, such as cooking, botanical or sewing machine oil. Most oils will just attract dust that then forms new layers on the locking mechanism, making the problem worse.
Some newer containers of WD-40 feature permanently-attached straws. Keep an eye out for these, as they’re just what you need. [3] X Research source A straw will also keep the spray of the lubricant confined inside the lock where you want it, rather than all over your front door.
Wearing gloves while handling lubricants can help prevent a slippery mess.
Make sure you’ve properly coated each part of the locking mechanism by running through the locking and unlocking action a few times. After you’ve applied WD-40 to the lock, the interior pins should disengage with no resistance and the cylinder should easily rotate when you turn your key. Lubricate the locks around your home with WD-40 regularly to keep them maintained.
Once applied, the graphite particles form a fine layer on the surface of the metal, lubricating and “brushing” away dust and dirt. A small container of powdered graphite can be purchased in most places for as little as $2.
Make sure you’re holding the bottle level so that graphite doesn’t escape around the opening. Consider covering the area of your door around the lock to guard it from stray graphite particles
Start by using a little bit of lubricant and apply more if the lock still sticks. Handle powdered graphite carefully. Otherwise, the fine black dust can get everywhere, staining surfaces and creating a big mess.
Sliding your key in and out of the lock will help spread the graphite around inside to the place where it most needs to be.
For especially stubborn locks, try squeezing a little graphite onto the door’s latch as well. This is the part of the locking mechanism that moves in and out of the door frame when you turn the knob. Lubricating the latch can help ease the keying action. [12] X Research source If you still don’t have any luck after trying powdered graphite, call a professional locksmith to come out and take a look at your locks. Sometimes the problem is with the pins inside the lock slipping down and loosening, which can’t be fixed with just lubricant.
