What size screw should be used to attach steel sheathing to a metal structure?

Using a self-tapping #8 screw is appropriate for attaching steel sheathing to a metal structure because it strikes a balance between strength and ease of installation. Self-tapping screws, particularly those sized #8, are designed to create their own threads in metal without the need for pre-drilling, which is advantageous in construction settings where time efficiency and structural integrity are essential.

The #8 screw provides sufficient tensile strength while also being capable of securing heavier materials like steel sheathing effectively. When fastening materials, it is important to select a screw that can handle the load requirements and is compatible with the thickness of the sheathing and substrate. The #8 size is commonly used in various metal applications, ensuring a good fit and a reliable hold.

In contrast, while smaller or larger screws may be used for specific applications, they may not offer the same balance of strength and ease of use. A #6 screw might be too small, risking insufficient grip on the metal structure, while a #10 or #12 screw might be more challenging to drive or could potentially create too large of a hole, leading to a weakened connection. Thus, #8 self-tapping screws are generally considered the standard choice for this type of application.