Nail length is given in “penny” sizes, written with a “d” (from the old British penny). This chart converts penny size to length with common uses.
| Penny size | Length | Common use |
|---|---|---|
| 2d | 1 in | Trim, small work |
| 4d | 1-1/2 in | Trim, lath |
| 6d | 2 in | Siding, trim |
| 8d | 2-1/2 in | Framing, subfloor |
| 10d | 3 in | Framing |
| 12d | 3-1/4 in | Framing |
| 16d | 3-1/2 in | Framing (most common) |
| 20d | 4 in | Heavy framing |
16d is the framing standard. For nailing 2x material together (like studs to plates), the 16d common nail is the workhorse. Use galvanized or stainless outdoors.
See the Screw Size Chart and Fastener Size Chart.