Cutting wings on the shaft counter-bore the deck board, helping to prevent fastener spin out. Cap-style head reduces mushrooming material, ensuring a cleaner-looking installation. Available with a Quik Guard® ; double-barrier coating and in stainless steel. #9 diameter with #2 Undersized square drive. Sharp point. Pre-drilling recommended near board ends to prevent splitting. Driver bit included in each package. NOTE: Quik Guard ® coating has been tested to show less than 10% of surface red rust at 950 hours of ASTM B117 salt spray testing. It is suitable for exterior applications with most preservative-treated woods. It is not suitable for higher exposure environments such as seaside applications.