These Phillips flat head self-tapping screws from Phillips are made from marine grade 316 stainless steel, making them highly durable and corrosion resistant. The countersunk head allows for a flush fit when fastening materials together, providing a seamless look. Available inquantities of 20 pieces across varying thread sizes and lengths, these screws are ideal for use in marine environments as well as other wet and humid conditions. Their hardened steel construction and self-tapping design makes installation quick and easy, drilling and threading into material in one single step for fastening wood, plastic, metal and more.