General description Specifically designed for fixing cement board to steel dry-lining frames (max. 3.0mm), these TIMCO Self-Drilling Cement Board Countersunk Exterior Silver Screws offer a reliable solution for your construction needs. The screws feature a self-countersinking head that ensures a secure and flush finish, making them ideal for a professional appearance. Technical specifications Dimensions: 4.2 x 42 mm Self-drilling point with a self-tapping thread Exterior grade coating for superior corrosion resistance in damp environments