These Tolsen self-drilling metal screws with a diameter of 4.2mm and a length of 16mm are designed to simplify your fastening tasks by eliminating the need for pre-drilling holes in metal surfaces. Each pack contains 500 pieces with a zinc-plated finish that helps protect the hardware from corrosion over time. Featuring a Phillips cross-head for a secure grip during installation, these 4.2x16mm screws are a practical choice for various metal construction and repair projects, specifically suited for thinner materials.