Which type of screw is used for fastening wood to wood where a flat surface is required?

A flathead wood screw is specifically designed for applications where a smooth, flat surface is necessary after installation. The unique shape of its head allows it to sit flush with the surface of the wood, providing a clean appearance. This characteristic is particularly beneficial in woodworking projects where aesthetics are important, such as furniture making or cabinetry.

In contrast, other options do not serve the same purpose. A finishing nail, while useful for attaching wood, does not provide the same level of surface finish because its head is typically smaller and may still be visible after driving it in. A fuse puller and a flaring tool are entirely different tools used for electrical and plumbing tasks, respectively, and have no application in wood fastening. Therefore, the flathead wood screw is the most suitable choice for fastening wood to wood when a flat surface is desired.