Expanded Metal Expanded metal is a form of metal stock made by shearing a metal plate in a press, so that the metal stretches, leaving diamond-shaped voids surrounded by interlinked bars of the metal. The most common method of manufacture is to simultaneously slit and stretch the material with one motion. Expanded metal is used in grates, outdoor furniture (e.g. benches), fencing, installation of heating floor system, plastering (metal lath). It is often used also for guarding to prevent contact with hot surfaces or machinery.