What Is a Metal Nail Made of?
Long an integral part of carpentry and general construction, the composition and form of nails evolve to improve old techniques and suit new applications. By definition, the shafts and heads of all nails are composed of metal. However, metal type of protective coatings vary according to the application of the nail, particularly the nail's installation location, the materials the nail must fasten and the required holding strength. With an understanding of nail metals and their characteristics, you can choose the right type of nail for your building project.
Metals of Manufacture
Steel is the most common metal of manufacture for construction nails. Workers across all construction trades use steel nails. For example, masonry workers use steel nails to construct concrete forms, carpenters to frame structures, plumbings and electricians to install strapping and secure boxes, and roofers and siding installers to install covering materials. However, special applications, such as boat building or metalworking, employ a variety of alternative metals, include stainless steel, aluminum, brass and copper.
Although many nails are bare, most metal nails available in home-improvement stores are coated with lubricating or protective compounds. Carpenters' framing nails, called coated sinkers, are often coated with a vinyl lubricant to aid quick, smooth entry. Alternatively, nails for outdoor building, roofing and siding require coatings to enhance corrosion resistance. The most common types of corrosion-resistant coatings are hot-dipped and electrogalvanized. Both types of coatings apply a layer of corrosion-resistant zinc to a bare nail's shank and head.
Nail shape, length and composition varies according to application. For example, thin nails without heads, called finishing nails, fasten trim pieces to interior surfaces. The finishing nails' heads sit flush beneath the trim's surface to create a streamlined look. Alternatively, roofing nails have large, flat heads that increase the nails' grip and resistance to wind loads. Nearly all types of nails are available in a broad range of lengths. Typically offered in increments of 1/8 to 1/4 inch, the right type of nail for a particular job depends upon the thickness of the components that the nail must join.
The unique designs of specialty nails enhance the nails' appearance or functionality. Examples of decorative specialty nails include cut head nails, which resemble the hand-wrought nails of a blacksmith's forge, and furniture tacks, which feature finish-quality, colored heads. Specialty nail designs that increase functionality include the ring-shank and spiral-shank nails. Often used to construct heavy-use items, such as shipping pallets, the grooves cut through ring- and spiral-shank nails' shanks increase the holding power.