From before biblical times, through the 1700s, nails were hand wrought, forged one at a time. The time consuming process made nails a valuable commodity—so much so that nails were sometimes used as a substitute for currency. People even deliberately burned down houses to be able to collect nails from the ashes.
In 1795, near the beginning of the Industrial Revolution, American inventor and mechanical engineer Jacob Perkins, patented a process for making nails cut from sheets of iron. The iron was oriented so that, when cut, the grain of the metal was parallel to the shank of the nail, making it stronger. The mass production of these cut nails made them cheaper and influenced construction methods, leading to the popularization of balloon framing and the decline of timber framing.
Cut nails eventually began to fall out of favor as wire nails were introduced in the mid 1800s. Manufacturing of wire nails was, at the time, an almost completely automated process, which made them even cheaper to produce. These nails were made from metal drawn into long strands of “wire” and are basically what we picture when we think of nails today. But, cut nails' old-time aesthetic, and their superior holding power still make them a viable option for certain projects.
The Advantages of Cut Nails
Faster and cheaper to produce doesn’t necessarily mean better, though. Cut, or square nails, do have some advantages over their round, pointed, modern day replacements. Their wedge-like profile gives them tremendous holding power. And despite their shape, they’re actually less likely to split the wood they’re being driven into.
The flat, square tip, when hammered, tears through wood fibers, breaking them as it passes through the wood. The wedge shape pushes the ends of the fibers down and gets tighter as the nail is driven deeper. These wood fibers act like angled teeth that help prevent the nail from backing out, giving it a lot more holding power than modern round nails that push their way between the fibers. That parting of the fibers as a wire nail passes through the wood is often the reason for wood splitting.
When to Use Cut Nails
The most common use for cut or square nails today is for face-nailing natural wood flooring. This is done for a decorative, rustic look as well as being a practical method for holding down wide-plank floor boards. Face-nailing through the top of the boards—instead of blind-nailing at the tongue edge—can help prevent cupping of the board in the center, keeping the floor flat and even.
Another common use for cut nails is in making rustic plank or barn doors. The style calls for vertical boards, with braces in a “Z” pattern nailed on to hold the planks together. Really, anything you construct that will have exposed nails and an historic aesthetic is appropriate project for cut nails. Tremont Nail Company makes dozens of styles and sizes to suit your needs. I recent used Tremont’s 2.5-inch square-cut fire door clinch nails, with a black oxide finish, for a wide-plank floor I installed. And they look fantastic. These have a nicely shaped, wider head and a reverse taper on the shaft near the head that lets the wood fibers relax and close back in on the nail, locking it in place.
The Types of Cut Nails
There are two main cut nail profiles you’ll see. The first is a straight-sided, wedge-shaped nail. The second is a wedge shape that tapers back down toward the head; this is called a clinch nail. They both come in different widths and lengths and are often named for their intended purpose (i.e. boat nail, sheathing nail, siding nail, etc.). Further, cut nails may have one of three types of heads: square, wrought, or rose. Wrought- and rose-head nails are typically used on softer woods, where the larger head helps keep the nail from pulling through. The smaller square-head nails are often used on hard woods, where there’s less risk of pull-through.
Whatever your project, if you have exposed nails and an old-fashioned aesthetic, there’s a cut nail to suit your needs.