Nails 101—Nail Sizes and Types Around the Home

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    Pile of nails against white background
    Michael Wildsmith/Getty Images

    The hammer and nail. Like peanut butter and chocolate, it's a classic combination that has been around forever. And while a hammer and nail may seem as simple as it gets, do you know which nail to use in every application? Just as hammers require some knowledge for using them effectively, nails have right and wrong uses. The right nail has the right strength, size, and other design features for the job at hand. The wrong nail for the job can result in a weak connection and/or damage to the wood. 


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  • 02 of 10

    How Nails are Sized

    Row of nails of different heights
    Erik Dreyer/Getty Images

    You've probably heard of nail sizes referred to as 10d, 16d, and so on. The number and "d" suffix are called the "Penny" system. The English penny used to be designated with a "d" representing the first letter of the Roman coin denarius. Today, the penny system refers specifically to nail length. A 2d nail is 1 inch long; a 16d nail is 3 1/2 inches long. Each higher number in the penny system represents a 1/4-inch length increase up to a 12d nail (3 1/4 inches long). After the 12d nail, the penny system does not have a clearly defined relationship to length.

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  • 03 of 10

    Common Nails

    Hillman Fasteners Common Nails

    Common nails are used for general construction and specifically for framing and other structural work. They have a thick shank, a wide head, and a diamond-shaped point. They are most commonly used with dimensional lumber (e.g., 2x4 framing). Their thickness makes them strong but also more likely to split wood than when using thinner nails. In some applications, it makes sense to actually ​dull the nail tip to prevent splitting the wood.

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    Box Nails

    Box Nail with Smooth Shank

    Box nails are similar to common nails but have thinner shanks and are better suited to thinner wood materials, like 1x (3/4-inch-thick) lumber and exterior trim. Box nails should not be used for structural projects because they don't have the strength and the holding power of common nails. The thinner shank of a box nail is less likely to split thinner materials. 

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    Duplex Head Nails

    Bright Double-head Shank Duplex Nail

    Duplex head nails are specialty nails useful for temporary construction, such as form work for pouring concrete. You drive the nail until the lower head is flush with the wood. When it's time to disassemble the project, you pull the nail using the upper head. 

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    Annular Ring or Ring Shank Nails

    Common Annular Ring Shank Type

    Annular ring also called ring shank, nails have rings on their shanks for extra grip and additional resistance to pulling out of the wood. They are commonly used for installing subflooring (to prevent squeaks from loose nails). Other nails that may have rings are drywall nails or deck board nails, also for pull-out resistance. 

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  • 07 of 10

    Masonry / Concrete Nails

    Masonry Nails and Fastener Gaskets

    Masonry and concrete nails are hardened nails, often with longitudinal grooves along the length of the nail's shaft. These nails are thick and very strong. They are designed to be fastened into concrete, concrete block, and mortar joints.

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    Brad Nails

    Multi-Pack Brad nails

    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 hardwood. Brads are ideal for general joinery and are usually countersunk below the surface of the wood using a nail set, then the hole is filled with putty for a finished appearance.

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  • 09 of 10

    Casing / Finish Nails

    Polish Finish Nail 6D

    Casing and finishing nails are similar, differing primarily in the shapes of their heads. A finishing nail has a small, slightly rounded head just a tad bit bigger than the nail shank. The head is designed to accept the pointed tip of a nail set, making it easier to countersunk the nail without slipping and gouging the wood. 

    A casing nail essentially is large finishing nail and is often used in exterior applications, such as for installing exterior trim boards and for nailing door frames and trim. They are commonly galvanized for corrosion-resistance. The nail head of a casing nail is tapered and may be set flush or just below the wood surface.

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    Roofing Nails or Clout Nails

    Electro-Galvanized Roofing Nail

    Roofing nails, sometimes called clout nails, have a short shank and a wide, flat, thin head. They can be used to fasten shingles, roofing felt, or sheet metal to wood. The shanks can be smooth or ringed for increased pull-out-resistance.