The most popular of all fastening agents is the nail. There are two common forms: wire nails (Fig. 107) and cut nails (Fig. 108). The wire nail is made of a cylindrical piece of wire, with one end sharpened to a point, and the other end flattened into a head. The wire nail is valuable because of its holding power and because it will not split the wood. A disadvantage is that it will bend unless hit squarely on the head.
A cut nail, as its name implies, is made from cut iron or steel. It has two flat, parallel sides and edges which taper from the head to the point, thus forming a wedge. When a cut nail is driven into wood, it should enter the wood across and never parallel to the grain. In this way the wedge-shaped nail enters the wood in its strongest direction, the length of the fibers. The holding power of the nail is thus increased and the wood is not split. Because of their clinching power, cut nails are generally used to secure the short hinges of a barndoor. Nails are packed and shipped in kegs (Fig. 110).