Coarse threads approximately 2/3 up shank draw board tightly to substrate. Pre-drilling always recommended and a must near board ends to prevent splits. 0.344 in Dia, #2 square drive bugle head. ‘Beaver Bite’ type 17 auger point for extra fast starts. For pressure-treated lumber.Coarse threads approximately 2/3rd up the shank draw the decking and other material tightly to the substrate350 count packs contain enough screws to fasten 100 sq-ft of deckingPre-drilling recommended near board ends to prevent splittingBugle head provides for flush countersinking