Using Nails in Woodworking
When you began woodworking, whether you’re a beginner or an accomplished artisan, did you expect that you’d use nails in your work? I didn’t. I looked at nails as something too common to use in better work. I searched for ways to join carcasses and mouldings that used anything but nails. Then, I visited the museums and began studying furniture construction.
Nails are present in many of the most treasured pieces of American furniture that line the walls and stock the backrooms of our museums. Wonder why? Nails are great connectors and, unlike screws which hold parts fast, nails allow for seasonal movement. As the woods expand or contract the nails bend to accommodate the movement. That’s a good thing. It’s what helped keep those treasures in their best condition. If the nails didn’t bend to allow for seasonal adjustments, cracks would result in cross-grain construction.
A Bit of History
Originally, nails were hand-forged. The process to make nails was slow and hard work. Nails were expensive.
Around 1750 the process of shearing nails from steel plates was developed. These nails are known as “cut” nails or “square” nails and within the next century, cut nails dominated the markets. Unlike hand-forging, machines made cut nails reducing the expense to the woodworker. One machine would shear the nail while a second would form the nail’s head. But they were still expensive.
In fact, in pre-1850 America it was common to burn dwellings that were to be destroyed in order to collect the nails from the ashes. If the nails were simply pulled from the building, workers could damage them.
By the beginning of the 20th century wire nails, those most used today, were developed. Round steel wire is cut, a head is formed and the end is sharpened to a chisel point all in one machine. Thousands are produced per minute. (Read more about wire nails including sizing, at appaltree.net/aba/nails.htm.) That’s progress, yet we continue to use the cut or hand-forged nails in furniture. Why?
If you’ve ever driven a wire nail into wood I bet you’ve had the wood split.
That’s because the chisel point of the nail drives or forces through the wood fibers, splitting the fibers along the way. One of the best tricks to learn when using wire nails is to flatten the nail’s point to lessen the possibility of splits. It’s contrary to regular thought, but it works.
Cut nails have that flattened point built right in. As a result, these nails maneuver through the wood fibers, twisting and turning as the grain directs. No splitting. But even better, as the nails twist and turn they are actually gaining a stronger grip in the wood. So, cut nails hold better versus wire nails.
Proper installation of square nails requires drilling a pilot hole. The size of the drill bit used is equal to the median width of the nail. And the pilot hole isn’t as deep as the nail. If you drill the pilot the entire length of the nail you’re creating a path for the nail and that lessens the twisting as the nails are driven, reducing the holding power of the nail.
Drill through the piece that is being attached, such as a backboard or a face frame, but only slightly into the second surface , the shelves or case sides. The shallow hole in the second surface helps guide the nail, but leaves enough wood intact for the end of the nail to grip.
Because square nails are wider in one direction than the other, it’s important to drive the nails correctly. Always orient the wide section of the nail with the grain. If the wide section is across the grain, splitting of the wood is likely because you’re wedging a piece of steel into the wood.
Nails that affix backboards to the cases (I like hand-forged nails for this task) are simply hammered tight to the surface while the heads of cut nails are set flush or slightly below the wood’s surface. Do you fill those recessed nail holes? I did at the beginning of my career, but now I allow the years of wax, dirt and the other age-adding impurities to fill those holes.
That’s my story. But, there are as many theories to installing nails as there are types of nails. For a bit different technique and point of view check out editor Christopher Schwarz’s article “Build Furniture with a Hammer” (MAR06WM_HAMMERS.pdf (427.89 KB))in our sister publication Woodworking Magazine.