Q. What is a rim lock used for?

Answer

A rim lock is a type of surface mount lock that doesn't penetrate the door's surface but instead attaches to the outside of the door and secures the door by use of a latch that slides into a keeper on the door's rim or frame. Knobs and handles made of porcelain, brass, and other materials are commonly used to activate the latch on rim locks. Doors that are too small for an internal lock mechanism often have rim locks installed. They are not recommended for outside doors due to how easily they may be opened with a screwdriver. Rim locks were traditionally forged from iron, but modern versions come in a variety of materials and coatings, including iron, composites, brass, and nickel. Body, keeper, escutcheon, and privacy latch are the parts that make up the lock.