Sheet metal screws, or tapping screws, are highly versatile. Though they are designed to attach metal to metal, they're also used to attach metal to wood, fiberglass, and plastic. Great for general repair around the house, their sharp threads draw materials together and ensure a secure hold. Sheet metal screws are fully threaded with a sharp point. A pre-drilled hole is NOT required for installation. Attaching Metal, Wood, Fiberglass and Plastic Sharp threads ensure a secure hold Zinc finish for moderate corrosion protection Design makes it easy for them to tap into and tighten against whatever they are being installed into Pre-drilled hole is required for these screws