... , galvanized, brass, copper and plastic.Shape of holesRound,Square,Rectangle,Triangle,Fish-scale,Diamond,Hexagon,Cross,Obround,Fish-mouth ... . Variations include 45 degree staggered and straight line pattern. Square hole: Staggered or straight line pattern.Slotted hole: Side ... if more practical, by the number of perforations to the Square Inch.MarginsPerforated Stock Size Sheet & Plates: The long sides ...