C-Deck Composite Deck Screws are for interior and exterior use with wood, composite and other plastic materials. These screws are specially designed to eliminate the mushrooming and blemishes that can occur on composite materials. They are also an excellent choice for wood decks, where the top threads work to pull down and hold warped lumber and lock the boards together. A multipurpose fastener which meets the challenge regardless of the material used.This top of the line fastener will not produce secondary lumps around the screw head leaving projects smooth and flush, complete with a professional flush finish. Milled with a trilobular design and a "Star Drive", C-Deck starts easy and drives with less torque and offers reduced splitting and snapping.Screw Products, Inc's C-Decks are available in ACQ Compatible e-coat or a 305 stainless steel combined with a color matched head. Avoid rust and corrosion in any exterior application. C-Decks are color matched in the U.S.A to give them the best color match.