This Science Buddies project explains how to build a mechanism that will reproducibly swing a hammer so you can determine the amount of force needed to hammer a nail through various densities of wood. The Science Buddies project ideas are set up consistently beginning with an abstract, objective, and introduction, followed by a section on terms, concepts, and questions, bibliography, list of materials and equipment, experimental procedure, suggestions on how to vary the experiment, plus a focus on the sort of careers this experiment might relate to.