... .steel,,Galvanized.steel,Aluminum,Brass,ect.The hole shap : Round, Square, Long round, Triangle ,Scale ,Diamond, and Oval etc.Aperture : In ... for something different.3.StraightA popular arrangement, straight center round hole patterns are available in multitude of sizes and ... requiring good visibility and through-put such as guards.5.Round - slot staggeredRound - slot, side staggered patterns are ideal ...