Expanded metal can be curved, bent, or rolled to different curvatures without any major distortions to the diamond-shaped pattern. Expanded metal is made from sheet metal uniformly slit and stretched. 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 mesh is formed from a single piece of metal. This means that there are no strained joins or welds that can work loose. This makes expanded metal ideal for forming and rolling.
Unlike perforated plate that punches holes out, expanded mesh is more economical and less wasteful thereby complying with modern-day “green” engineering standards. Expanded metal has a higher strength-to-weight ratio than sheet metal because expanding the metal from its solid sheet form adds strength in the process. This makes the mesh ideal for catwalks, stairs, ceiling panels, platforms, screens, grills, ventilating equipment, and safety guards. The openings permit the passage of light, air, heat and sound. The picture below shows expanded metal curved into half pipe as a cover for machinery.
Most of the expanded metals are made from common grades such as hot rolled, cold reduced and galvanized steel. There are three major types of expanded metal: raised, flattened and decorative. The raised pattern is sometimes called the “standard pattern” and in its rawest form has a raised surface. The flattened pattern is manufactured by passing the raised pattern sheet through a cold-roll, reducing mill. Flattened and expanded metal turns the strands and bonds down to provide a flattened surface, reducing the thickness and elongating the pattern. The decorative expanded metal comes in many patterns and has a more aesthetically pleasing design. In addition to machinery and equipment applications, architects who strive to give an industrial flavor to their designs often turn to the many varieties of expanded metals, either flat or curved.