Keyhole

The keyhole, “ojo de la cerradura” in Spanish, is the everyday name for the opening you put your key into, what the trade calls the keyway. Behind it is the slot of the cylinder or, in lever locks, the lever mechanism.

It is the most exposed part of the lock and the one that suffers most in daily life. A few tips prevent a lot of faults:

• Do not put glue, cocktail sticks or paper clips in it to “fix” anything.
• Do not use cooking oil or thick lubricants, which trap sand.
• If the key feels rough going in, clean with air and use a dry lubricant.
• If someone has deliberately put something inside, do not force the key.

In beach houses shut up for months, the keyhole fills with dust and salt and the key may jam when you come back. If that happens, see what to do when the key will not turn or ask for a cylinder replacement.