... ventilation.2)The main products is also called punch plate, perforated plate, perforated plate, mine screen, screen machine.2.Features1)Rugged, handsome ... than 3mm.3)materials:low carbon steel, stainless steel plate, galvanized plate.4)Sieve-shaped with round hole, square hole, diamond hole ... pore size 0.4mm--100mm.6)5mm thick stainless steel plate can be punched 5mm diameter hole. China punching hole ...