Silicon Bronze is the traditional choice for marine construction. It is corrosion resistant, helps prevent rot around the screw holes when used under water, and is relatively strong. Although stronger than Solid Brass, Silicon Bronze screws are not as strong as Stainless Steel. They require a carefully sized pilot hole to avoid breakage. We recommend drilling twice (once for the root and once for the shank) as well as using Ackempucky Fastener Lubricant to avoid breakage.