... carbon steel ,G I ,SS Technical:perforated Hole punch sheet metal :1. Hole Punching Metal Mesh Material: Low carbon steel ... steel board, copper board and nickel board.2. Hole Punching Metal Mesh Characteristics: The surface is flat, ... and grain storage ventilation, mechanical protection5. Hole patterns of Hole Punching Metal Mesh: Round, Rectangular hole, square, Triangle, Diamond, Hexagonal, ...