What size is a 16d nail?
A 16d common nail is 3 1/2" long and 0.162" thick — the standard framing nail. Every penny size from 6d to 20d, and where the rule of thumb for them stops working.
A 16d common nail is 3 1/2" long with a 0.162" shank — the nail a framing schedule means by 16d.
A 16d box nail is the same length but thinner, at 0.135". Commons run about 49 to the pound, boxes about 71.
How that is worked out
- The d is a penny — the old English abbreviation for a denarius, from what a hundred nails once cost. It names a length by convention, not by any arithmetic.
- The rule people quote is penny ÷ 4 + 1/2": it gives 3" for a 10d, which is right, and 4 1/2" for a 16d, which is 1" too long. Past 10d, read the table.
- Nails to the pound comes from the steel: a 0.162" × 3 1/2" shank weighs about 0.0204 lb, so about 49 in a pound.
Framing nail sizes, ASTM F1667 shank diameters
| Penny | Length | Common | Box | Commons per lb | Rule of thumb |
|---|---|---|---|---|---|
| 6d | 2" | 0.113" | 0.099" | 176 | holds |
| 8d | 2 1/2" | 0.131" | 0.113" | 105 | holds |
| 10d | 3" | 0.148" | 0.128" | 68 | holds |
| 12d | 3 1/4" | 0.148" | 0.128" | 63 | says 3 1/2" |
| 16d | 3 1/2" | 0.162" | 0.135" | 49 | says 4 1/2" |
| 20d | 4" | 0.192" | 0.148" | 31 | says 5 1/2" |
Worth knowing
- Common nails are what a nailing schedule assumes unless it says otherwise. A box nail of the same penny is thinner, holds less and splits less — the trade you want near the end of a board.
- Nail-gun nails are sold by length and diameter rather than by penny, and many framing nails for guns are thinner than a 16d common. If the plans call for 16d commons, match the diameter, not just the length.
- Nails per pound is worked out from the shank volume and agrees with the box to within a nail or two; coatings and heads move it a little, so treat it as an estimate and the box weight as the fact.
Sources: ASTM F1667, Standard Specification for Driven Fasteners: Nails, Spikes, and Staples, ASTM International.
Work out your own numbers
- Nail sizes
What a 16d actually measures, common against box against finish, and how many come in a pound.
- Screw length
How long a screw to put through one board into another, and whether the tip comes out the far side.
- Wall framing stud count
Field studs at 16" or 24" on centre, corner studs, and the king and jack studs every opening adds.
Related questions
- How long is a 16d nail?
- 3 1/2", whether it is a common, a box or a finish nail. The families differ in thickness, not length: a 16d common is 0.162", a 16d box 0.135".
- What is the difference between a 16d and a 10d nail?
- 1/2" of length and some thickness: a 10d common is 3" × 0.148", a 16d 3 1/2" × 0.162". The 16d is for nailing through a 2x into another 2x; the 10d is common for toenailing and for nailing through thinner stock.
- How many 16d nails are in a pound?
- About 49 commons, or 71 of the thinner box nails. Galvanised nails carry zinc and run a few fewer to the pound.