TIMco 4mm X 25mm Pozidriv Double Countersunk Zp Solo Chipboard & Wood Screws 200 Pack. A single thread woodscrew mainly used in various types of timber and man-made boards or into masonry with the use of a plastic plug. Features: Double countersunk reduces the likelihood of head shear and assists completion of countersinking. Wax lubricated to enhance screw insertion time, extra driving torque and resistance to corrosion. 40° Deep single thread to provide a secure fixing with high pull-out resistance. 25° Sharp point and single lead for a fast start and improved thread acceptance. All sizes up to and including 75mm are fully threaded and lengths 80mm and above all have 70mm thread length. Finish: Zinc & Yellow. Head Type: Double Countersunk. Material: Carbon Steel. Thread Coverage: Fully Threaded. Driver Bit Size: PZ2.