Understanding Nail Sizes and Basic Types

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 2 x dimensional lumber. Their thickness makes them strong but also more likely to split wood than when compared to thinner nails. Some carpenters actually dull the nail tip to prevent splitting the wood, though to do so means the tip will tear the wood fibers, thereby slightly reducing the holding power. 

A special type of common nail is the sinker, which has a slightly narrower shank and a special head designed to be sunk flush with the surface of the wood. 

Box Nails

Box nails are similar to common nails and sinkers but have thinner shanks and are better suited to thinner wood materials, such as  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. 

Duplex Head Nails

Duplex head nails are specialty nails useful for temporary construction, such as formwork for pouring concrete or attaching temporary cleats during roofing work. You drive the nail until the lower head is flush with the wood. When it's time to disassemble the project, you can extract the nail using the upper head and the claw of your hammer or pull bar. 

Annular Ring or Ring Shank Nails

An 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, where the extra holding power can help prevent floors from squeaking. Other nails that may have rings include drywall nails or deck board nails, also for improved holding power. 

Masonry/Concrete Nails

Masonry and concrete nails use hardened steel, often with longitudinal grooves along the length of the nail's shaft to help them penetrate very hard materials by spiraling as they are driven. These nails are thick and very strong. They are designed to be fastened into concrete, concrete block, and mortar joints.

Casing/Finish Nails

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

A casing nail essentially is ​a large finishing nail. It 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.

Brad Nails

Brad nails (or brads) are used in light finish woodworking​ and are essentially very small finishing nails. 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—the holes are then filled with putty for a finished appearance. Brad nails can be made for use in a nail gun (as pictured here) or to be hand-driven.

Roofing Nails or Clout Nails

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.