brad
A small, thin nail used for delicate wood projects.
A brad is a thin nail with a small head, almost invisible once it's hammered in. Carpenters and woodworkers use brads when they want to attach pieces of wood together without obvious nail heads showing. Picture building a birdhouse or a picture frame: regular nails might split the thin wood or leave ugly bumps, but brads slide in smoothly and barely leave a mark.
Brads work especially well for delicate projects like attaching trim around doorways or securing the backing on a piece of furniture. Because their heads are so small, they can be pushed slightly below the wood's surface and covered with a tiny dab of wood filler, making them almost invisible.
While regular nails get pounded in with heavy hammer blows, brads are small fasteners that hold things together with more finesse than force.