The small deeply countersunk heads and slender shanks are easily driven flush with or below the surface. Ideal for fastening corner boards, balusters, handrails, piers and docks, or any decking work. 1 square drive bit is included with each box. Grade 305 stainless steel. Suitable for new treated lumber. Coarse threads approximately 2/3 up shank, draws board tightly to substrate. Pre-drilling recommended. Pre-drilling is a must near board ends to prevent splits. Wear safety glasses when using this product.