These Phillips flat head sheet metal screws are a #8 x 3 in. size, supplied as a box of 100. Sheet metal screws, or tapping screws, are highly versatile: they are designed to attach metal to metal and are also used to attach metal to wood, fiberglass and plastic. They are great for general repair around the house, and the sharp threads draw materials together and ensure a secure hold. The screws are fully threaded with a sharp point. A pre-drilled hole is required for installation.