The most striking feature of the cage nut is the square sheet metal cage that encloses the nut. This cage is attached to sheet metal into which no thread can be cut in order to provide a nut thread despite the thin material. In addition, the cage is provided with noses that can snap into corresponding holes in the sheet metal.
An application example is a so-called '19-inch rack' in which components of servers, network distributors or laboratory equipment are installed. The usual size of cage nuts in such 'racks' is M6.