Rock-On 23320 2-1/4 Inch Zinc Plated WaferHead Phillips Screws 100 Pack For Attaching Cement Board To Wood and Light-Gauge Steel Ideal for attaching durock and wonderboard to wood and light gauge steel Use these screws on a variety of projects including work with bathtubs, Showers, Countertops and flooring applications Zinc-plated steel construction Climacoat coating provides protection against rust and corrosion