... , square, circular, angular, scale-shaped Opening Dia. : 0. 3-100mm hole punching perforated metal sheet:Materials: cold-rolled steel plate, hot-rolled ... -25mm; Length: 20m2. Openin Dia: 0. 3mm-25mmProcessing: the punched hole metal mesh, used to be in filteration & ventilation, set foot ... to it's characteristics of fireproof, enviroment friendly, beauty etc, hole punching mesh