The parts of the nail are the head, shank or shaft, point, and the gripper marks – slight grooves incised into the shank near the head of most (but not all) varieties of nails.
The nail functions by displacing wood fibers when it is pounded into the workpiece, and the pressure exerted against the shaft by the displaced wood provides the holding power.
Nails are sometimes referred to by their length in inches, but more often the traditional terminology of the penny is used. Dating from the days when nails cost a lot more than they do today, the term penny identifies the size of a nail. In an earlier era, one hundred nails of a certain size cost three pennies; hence the name “threepenny nail.” One hundred nails of the next size cost four pennies, and so on. The pricing structure has long since been abandoned (today, nails are sold by the pound), but the nomenclature of the penny survives.
The word penny is often abbreviated in the British style by the letter d (for denarius, a Roman coin) — as in “3d nails,” for example, to identify “threepenny nails.” Nails shorter than one inch are generally identified by fractions of an inch rather than by pennies.
Wire nails are indeed the rule today, but not all wire nails are the same. They vary in size and in other ways as well. Various nails are manufactured for specific purposes, with differently proportioned and shaped heads and shafts.
Nails are made of brass, aluminum, and copper, though most often of steel. The steel may be plain or galvanized, the latter being the right choice for damp applications where a rust-resistant nail is required.
The following are eleven of the most common kinds of nails.
Common Nail. As the name suggests, these are your everyday nails. Used for rough construction work, the common nail can be purchased in lengths varying from one to six inches (2d to 60d). The largest common nails are colloquially known as spikes.
Box Nail. These look like common nails, but are thinner. This means they are less likely to cause splits in the wood; as they displace less wood, they also have less holding power, so are not generally used where structural strength is critical. Box nails are generally available in lengths from one inch to three and a half inches.
Finishing Nail. Finishing nails are (surprise, surprise) used for finish work. When the nailhead will show in the final product (as with moldings, for example), finishing nails are often used because their barrel-shaped heads are small and can be driven below the surface of the wood using a nail set (a technique called countersinking). Finishing nails are generally available in lengths ranging from one to four inches (2d to 20d).
Casing Nail. A near relation of the finishing nail, the casing nail is slightly larger and has increased holding power. It is most often used for attaching moldings such as window and door casings where added strength is required.
Brad. Brads are essentially diminutive finishing nails, proportionately smaller in diameter and length (one inch or less). They are used in making frames, attaching plywood paneling, and in cabinetwork.
Roofing Nail. Roofing nails have disproportionately large, round heads and heavier shafts for their length. They are designed to hold roofing materials in place, in particular composition and asphalt- based materials. In order to resist rust, roofing nails are heavily galvanized or made of aluminum. Three-quarter-inch to one-and-three- quarter-inch sizes are usual; the penny system is not used in reference to roofing nails.
Masonry Nail. Several types of masonry nails are sold; all are designed to be driven into brick or concrete walls. These hard nails may be rectangular in section or have fluted shafts, but all are hardened to resist bending and breaking as they are driven into almost rock-hard materials. Given the nature of masonry materials, be sure to wear safety glasses or goggles when nailing masonry nails, as flying chips pose a danger to your eyes.
Cut Flooring Nail. The lone surviving direct descendant of the once-dominant cut nail is the flooring nail. These nails are large, strong, and are often used in a nailing machine.
Spiral Flooring Nail. Spiral flooring nails feature a spiraled shaft and were traditionally used for nailing subfloors. Nail guns and the specially designed nails used in them have superseded these nails in much construction work today.
Annular Ring Nail. Often sold in galvanized steel, annular ring nails are commonly used as siding nails, to hold clapboards or shingles in place, or for underlayment or paneling. They are thin, lined with rings for added holding power, and resistant to rust.
Duplex Nail. This is a variation of the common nail. Featuring a second head formed a short distance down the shaft from the end ot the nail, the duplex nail is used for temporary construction (like scaffolding and staging) because it can be driven snug, yet be easily removed.
Other Nails. Drywall nails, which feature rings on their shafts, are sold for hanging wallboard; their heads are traditionally driven slightly below the surface of the plaster panel (the hammer stroke creates a dimple that is then filled in with joint compound or plaster). Cement-coated nails are roughly the size and weight of box nails, but are coated with a resin for added holding power. They’re used to nail outside sheathing.
Many of the varieties of nails discussed above are also sold in magazines for use in air-powered nailers. Framing, finishing, and roofing nails, as well as brads and flooring nails, are commonly available for such equipment.