There are so many types of nails; it is often difficult choosing the correct one for the job. Choosing the correct nail is critical if you want a joint that will stand the test of time. Choosing the correct nail will depend on the type of material you will be joining together and the application. Using the wrong nail for the job can cause damage to the wood and lack holding power.
Nail History 101
Wherever you buy your nails I am sure you have seen sizes such as 16d or 8d nails, or heard the term 16 penny nail.. Have you ever wondered how nails got their names? Let me explain the history.
There are a couple of schools of thought as to how the name “penny”, such as 16 penny stuck through the years. The most often and believable story is that since nails used to be sold by the hundred, the small nails cost less since they weighed less and a hundred two-penny nails cost two pence, a hundred eight-penny nails cost eight pence and so on.
In this day and age the “penny” notation refers only to nail length. The most frequently used nails are the 16p which is 3 ½” long and the 8p nail which is 2 ½” long. Typically these types of nails will come in 2 types, a common nail with a disk-shaped head that is typically 3 to 4 times the diameter of the shank and a box nail which has a thinner shank. Box nails are not used for conventional framing because of this thinner shank, which simply equates to less holding power.
Typical Nail Sizes and Their Length in Inches
|2d nail = 1”
||9d nail = 2 ¾”
|3d nail = 1 ¼”
||10d nail = 3”
|4d nail = 1 ½”
||12d nail = 3 ¼”
|5d nail = 1 ¾”
||16d nail = 3 ½”
|6d nail = 2”
||20d nail = 4” considered a spike
|7d nail = 2 ¼”
||30d nail = 4 ½” considered a spike
|8d nail = 2 ½”
||40d nail = 5” considered a spike
There is also a coating that can be added to common framing nails. Nails that are coated with this adhesive (cement) for greater holding power are called “cement coated”. This coating melts from friction when driven in, and when it cools it adheres to the wood. The “cement coating” color varies by manufacturer, although tan and pink are common colors for this coating.
A good rule to follow is to choose a nail that is three times as long as the thickness of the material you are fastening. If you want to hold 1/2″ drywall to a stud wall, the length of the nails should be at least 1 1/2″. This is a reasonable guide most of the time. When nailing very thin materials into wood, a minimum of 1/2″ of penetration is necessary. If you are attaching something very heavy and the nail is the sole support or attachment point, consider using screws.
Other Types of Nails
Cut Nails were first used in the 1700’s. Cut nails are often used to attach wood to concrete block, mortar joints, and brick or to fresh concrete. For best results you want about 3/4” of penetration into masonry for good holding power. Cut nails are cut or sheared from steel plate and are generally hardened. They have a wedge shape with a square, blunt point which reduces spalling during penetration into concrete or masonry. Cut nails are thick and because they displace more wood fiber, they have greater holding power than standard nails. Since the end is blunt it tears through the wood fibers instead of spreading them like a pointed nail.
Duplex Head Nails are a specialty nail useful for temporary construction, such as concrete forms, or building temporary scaffolding. The nail’s double head (duplex) makes it easier to remove and pull out of the form boards or other temporary construction.
Drywall or Ring Shank Nails are another specialty wire nail that has rings on the shank providing better grip and additional resistance to pull-out of the lumber. This type of nail is also used for drywall nails or deck board nails because of the pullout resistant feature of the annular rings on the nail shank.
Brad Nails are used in light finish woodworking. Because of the small shank diameter and the small head, these nails greatly reduce the possibility of splitting when used in hard wood. Brads are ideal for general joinery and are usually countersunk below the surface of the wood and filled to give smooth appearance.
Casing and Finishing Nails are similar and differ primarily in the shape of the heads. A finishing nail has a small slightly rounded head just a tad bit bigger than the nail shank. The head is designed to fit into a nail set to be countersunk and the nail hole filled.
A Casing Nail is often used in exterior applications and is often galvanized. The nail head of a casing nail is tapered and may be set flush or just below the wood surface.
Roofing Nails are used to fasten shingles, roofing felt, or sheet metal to wood. The shanks can be smooth or ringed for increased pull out resistance.
Galvanized Nails are more a treatment to the nail rather than a different type, this type of weather and corrosion resistant coating can be attached” to the nail, through several different processes.
There are, of course, specialized nails for use with different materials, some of which we spoke about above, but there are many more. Nails are also made out of all sorts of metals… aluminum, iron, steel, and rustproof stainless steel. Some are coated with zinc, known as galvanized nails, to be more rust resistant. Some are hardened by heat so that they can be hammered into very hard materials, such as cement nails. There are also special nails for hardwood flooring, and upholstery. There seems to be an ever-increasing array of specialty nails, with new nails being developed as new products are also developed.
There is an entire family of nails for use in power actuated nailing guns. These nail guns driven by electricity or compressed air, use nails that are manufactured in strips, or coils. A nail gun can be used to install trim, roof shingles, or even in the framing of a home. They are very helpful but also can be dangerous if used improperly.
When you are going to fasten an unusual material you will want to check with the supplier or manufacturer to see if they have a speciality fastener. One such product that comes to mind is foam insulation board, or Celotex (brand name). There are specifically designed “cap nails”, a ring shank nail with a plastic washer about the size of a quarter that helps to keep the nail head from pulling thought the soft foam material
There you have it, a quick lesson on nail history and uses. If you need a few tips on how to hammer a nail, check out my video “How to Hammer a Nail” at the Contractor John Web Site.