Originally Posted by crawdaddio

WD-40 is a water displacement product. It is used as a cleaner, not a lubricant. When it dries, it will also attract particulates, gunking up your lock. It SHOULD be used on OLD, gunky, rusty, cruddy locks to clean them out. Spray some into the keyway and all moving parts. Wait 5 minutes or so and wipe as much out as you can. Wait as long as you can to let it dry out, and apply a teflon lubricant.