The word “plate” is generally used in reference to thick metal planes, though there is no universal minimum thickness that a metal plane must meet before being designated as a metal plate.
The words used to describe such metal products are qualitative and are usually meaningful only in reference to each other. For example, a perforated metal plate seems more likely to be used as a floor panel or drain covering than would a perforated metal sheet.
It is this difference that informs an understanding of the words used to describe different metal products. While plates do not have to be of a specific size in order to be considered plates, they are generally accepted to be the appropriate raw materials for more demanding applications.
For example, architectural perforated metal that serves access restriction purposes in addition to its role as an aesthetic improvement must be able to retain an attractive appearance while also deterring unwanted access to restricted spaces.
Such products are used in the construction of cabinets and some kinds of doors. Plates are thin enough to be easily punched with decorative shapes and thick enough to resist impact or other kinds of trauma.
Perforated plates can be made out of many different materials. Perforated steel plates are often the best choice for applications in which the plate is likely to be subject to impact or the bearing of heavy loads; perforated steel plates are often used as floor gratings or as wall paneling.
Aluminum is known for its light weight and resistance to corrosion. It is not as strong as steel, so it is not usually employed in very demanding applications. However, because of its resistance to oxidation it can be used in ways in which steel cannot.
For example, outdoor perforated metal seating and decorative paneling are often made out of aluminum plates instead of steel. Copper, brass and many other metals can be rolled into thick plates and perforated, but they are less commonly used for such purposes because of their high price compared to other metals like steel and aluminum.
Perforated copper and brass products tend to be much thinner and are used in low-demand applications.