Nail Types: What Actually Matters When You Pick One

Nails look simple but picking the wrong one causes split wood, weak holds, or rust stains on exposed work. Here's what actually matters when you're choosing.

The main types

Common nails

The workhorse. Thick shaft, large head. Good for framing and rough carpentry where strength counts more than appearance. Sizes 2d to 60d (1" to 6").

Finishing nails

Smaller head that can be countersunk and filled. Used for trim, cabinetry, moldings. If you're painting the surface, these are what you want. Sizes 2d to 16d.

Brad nails

Thinner still — 18-gauge. Good for thin trim, paneling, decorative work. These won't split narrow moldings. But they're fragile under real stress, so don't use them where there's load involved.

Roofing nails

Big flat head, holds down shingles and felt. Hot-dip galvanized because they sit exposed on every roof. Use uncoated ones and they'll rust through in a single season.

Masonry nails

Hardened steel, fluted shaft. For driving into concrete or brick. Don't confuse with concrete screws — these are impact-driven, not threaded.

Box nails

Like common nails but thinner. Less likely to split thin wood. Used for light framing, boxes, crates. Tradeoff is lower holding power.

What actually matters

Think about what you're fastening, how much load it carries, and whether the nail will be visible. The rule: penetrate at least two-thirds into the second piece. For anything outdoor or wet, galvanized or stainless. Don't use common nails in trim — the head is too big to hide.