Kinds of Nails and Their Uses
Nails are usually used for joining pieces of wood or for fastening other materials to wood. They are simply hammered into place and are held there by friction. Some have roughened shanks so that they will hold better.
There is a tremendous variety of nails, since they are used for so many different purposes. There are many different kinds made for specialized uses, but only a few are used for most ordinary wood construction. These include the common nail, the box nail, and the finishing nail. All are available in different lengths and gauges, or diameters.
- The ordinary all-purpose ones most of us use are called common nails and are most widely used.
- Finishing nails, used in furniture and cabinetwork, have very small heads that do not show on the finished work. They have very small heads and are used when it is undesirable to have the nail head showing. The smallest ones are called brads and are used to fasten thin moldings or panels.
- Box nails are slightly thinner than common nails and are not as strong. They are used for light construction.
- Roofing nails have very large heads. They are used for nailing shingles or tar paper to a roof. The large head holds the thin material and keeps it from tearing loose.
- Some nails have two heads, one above the other. The nail is driven only as far as the first head. The top head of the nail remains above the surface of the work, to make it easy to pull the nail out. Two-headed types are used to hold scaffolding and other temporary structures together.
Most nails have notches, or grooves, near the head so that they will hold better. Some have screwlike threads for extra holding power. Specially hardened nails, designed to be driven into concrete or masonry, have longitudinally grooved shanks for a tight grip. There are also special double-headed ones for nailing temporary structures.
The most effective way to drive a nail is to strike it with a hammer squarely on the head. When driven in this way, it is less likely to bend or break. Nails should always be driven at a slight angle to the grain of the wood so that the wood does not split. The nail must be strong enough, and it should be long enough so that it completely penetrates one piece of wood and at least half its length penetrates the other piece.
History of Nails
Nails have been used for at least 3,000 years, and during most of that time they were individually made by forging the metal and hammering the heads. Modern nail-making machines were developed from a machine invented by Ezekiel Reed of Massachusetts in 1786.
Most nails are made by machine from heavy steel wire. These machines can make hundreds of nails per minute. First, the machine cuts the wire to the correct length. Then it flattens one end of the wire to make the head. And finally, it cuts the point at the other end.
Most nails today are manufactured from steel wire that is fed from large spools into a machine that cuts it into individual nail lengths. Grippers hold the piece of wire firmly while a powerful hammer strikes one projecting end, flattening it to form the nail's head. It is then moved forward, and two knives converge on it, cutting it to the proper length and making the point.
Some types of nails, called cut nails, are stamped, or cut, from sheets of metal. These are rectangular rather than round.
Most nails are made of steel. Masonry nails, used on concrete or masonry, are made of specially hardened steel. Some nails, such as roofing nails, are galvanized. That means they are coated with zinc to prevent rusting.
Nails used on boats must be extra rustproof. They are usually made of brass or bronze. Large nails are called spikes, and are usually over fifteen centimeters long.