A double-headed nail, or duplex head nail, is the nail of choice for quick projects such as construction scaffolding, form work or temporary braces. Double-headed nails are as strong as common nails but feature two heads for easy removal. The nail is driven into the surface to the first head, leaving a small bit of the nail and the second head sticking out. All you need is the reverse end of a claw hammer to remove a double-headed nail.