Expanded metal sheet can be different type and material, the expanding process uses special machines to cut metal sheets (such as steel plates, aluminum plates, etc.). The cutting method is not complete cutting, but forming a series of cuts according to a certain pattern and spacing. These incisions create conditions for the subsequent stretching process. For example, the cutting pattern can be an arrangement of shapes such as diamonds, squares, etc. After cutting, the metal sheet is pulled apart from the incision by mechanical force, causing the metal to stretch along the incision and form a mesh. The degree of stretching can be adjusted as needed to obtain different sizes of mesh holes and thicknesses of sheets. The surface area of the stretched metal plate will be much larger than that of the original thin plate, and it will have a three-dimensional structure.