The TIMCO Concrete Screws Flat Countersunk Exterior Silver – 7.5 x 80 provides a rapid and effective light duty anchoring system for fixing into concrete, brick, stone, concrete block and wood. These through fixings offer a single solution that replaces traditional fixings such as nylon frame and hammer fixings. Features include TX30 drive recess to reduce driver wear and prevent camming out, serrated V-threads for optimum insertion into all masonry types, and exterior plating that provides reliable corrosion resistance tested to 500 hours salt-spray. The high-low thread design ensures ease of insertion, making them ideal for fitting windows and door frames.