Abstract: A nail driving apparatus comprising a tube, a rod with a mass attached to one end, a spring connecting the mass to the tube, and a sleeve encircling the exposed portion of rod between the tube and the mass. When the mass is in the forward, closed position, the spring is slightly stretched, holding the apparatus in the closed position. When the mass is drawn away from the tube, the spring is displaced, increasing the tension in the spring and, thus, aiding the user in driving a nail. An expandable sleeve protects the exposed portion of rod between the tube and the mass from being contaminated by debris. It also prevents the user's hand from being positioned at the point of contact. As the mass is drawn away from the tube, the sleeve expands to protect the entire length of exposed rod.