How to lubricate the lock core

Pencil ash can be used for lubrication. Just scrape a little pencil ash off the sharpened pencil with a knife, and then pour these pencil ash into the door lock. Of course, you can also use some lubricants, but you should choose the lubricating products used in mechanical operation, and you should not use edible oil or sesame oil to lubricate the door lock, because they are sticky and will accelerate the wear and tear of the door lock.