Use this screw for fastening all types of wood decking, including cedar, redwood and preservative-treated woods. Bugle head provides for flush countersinking.Mfg of 18-8 (300 series) Stainless Steel, Type 17 Cutting Point Type-17 point for fast startsCoarse threads approximately 2/3 up the shank draw the decking and other material tightly to the substratePredrilling recommended near board ends to prevent splitting