When screwing two pieces of wood together, use the traditional wood screw over the drywall screw for better results. A drywall screw is threaded the full length. Since the top threads tend to grip the first board it enters, this can force two pieces of wood apart slightly because you have threads in both boards. The top part of a wood screw, on the other hand, has a smooth shank that won’t grip the first board. This makes it easier to clamp two pieces of wood together. There’s another reason to avoid drywall screws: The hardened, brittle steel shafts of drywall screws will often break during installation, especially when screwed into hardwoods. Removing them from a finished material is nearly impossible and getting them out damages the surface.