Nail sizes, and what the d means
Pick a penny size for its real length and shank diameter, the difference between a common, a box and a finish nail, and how many come to the pound.
1 lb and 5 lb boxes are the usual two
A 16d common nail is
3 1/2"× 0.162" shank
Per pound
49
500 nails weigh
10.2 lb
5 lb boxes to buy
3
Where to buy this
- 3 × 5 lb 16d common nailsHome DepotLowe'sAmazon
Coating is the choice this page does not make: bright nails rust, and anything outdoors or in treated lumber wants hot-dipped galvanised or stainless.
Plain search links, nothing sponsored. Prices and stock are the shop's, and a local lumberyard will usually beat both on solid stock.
The formula, and where it stops
The quoted rule is penny ÷ 4 + 1/2", and it is exactly right from 2d to 10d. At 16d it gives 4 1/2" and the nail is actually 3 1/2" — past 10d the table is the authority and the formula is a coincidence that ran out.
Why a common nail
The framing nail. Thickest shank of the three and a wide flat head, which is what a nailing schedule assumes unless it says otherwise.
Every penny size, common
- 2dabout 868 to the pound
- 1" × 0.072"
- 3dabout 562 to the pound
- 1 1/4" × 0.08"
- 4dabout 312 to the pound
- 1 1/2" × 0.098"
- 5dabout 268 to the pound
- 1 3/4" × 0.098"
- 6dabout 176 to the pound
- 2" × 0.113"
- 7dabout 157 to the pound
- 2 1/4" × 0.113"
- 8dabout 105 to the pound
- 2 1/2" × 0.131"
- 10dabout 68 to the pound
- 3" × 0.148"
- 12dabout 63 to the pound
- 3 1/4" × 0.148"
- 16dabout 49 to the pound
- 3 1/2" × 0.162"
- 20dabout 31 to the pound
- 4" × 0.192"
- 30dabout 23 to the pound
- 4 1/2" × 0.207"
- 40dabout 18 to the pound
- 5" × 0.225"
- 60dabout 11 to the pound
- 6" × 0.263"
Diameters are the ASTM F1667 figures. The count to the pound is the volume of the shank times the density of steel, which lands on the published counts because the head and the point roughly cancel — real boxes vary by maker, and a hot-dipped galvanised nail carries measurable zinc.
About nail sizes
- What does the d in 16d mean?
- Penny — from the Roman denarius, by way of what a hundred nails once cost. It says nothing about the nail except by convention, so 16d is simply the name of a 3 1/2" nail. There is a formula people quote, penny ÷ 4 + 1/2", and it is exactly right from 2d to 10d and then breaks: it predicts 3 1/2" for a 12d, and a 12d is 3 1/4". Above 10d the table is the authority.
- What is the difference between a common and a box nail?
- The shank. Same length, thinner wire — a 16d common is 0.162" and a 16d box is 0.135". The thinner nail holds less and splits less, which is exactly the trade you want near the end of a board or in thin stock. It matters for more than splitting, though: a nailing schedule that calls for 16d commons is assuming that diameter, and substituting box nails quietly reduces the connection.
- How many nails are in a pound?
- About 49 for a 16d common, 69 for a 10d and 106 for an 8d. That is not a lookup here — it is the volume of the shank times the density of steel, which lands on the published counts almost exactly because the head and the point roughly cancel out. Real boxes vary by maker and by coating, so treat it as an estimate: hot-dipped galvanised nails carry measurable zinc and run fewer to the pound.
- Can I use finish nails to frame with?
- No. A finish nail's head is barely wider than its shank, which is what lets it set below the surface and be filled — and it is also what makes it useless in shear against a bearing member, because there is no head to stop the wood pulling over it. Finish nails are trim fasteners. Nothing structural on this site is calculated with one.
You might also need
- Fastener calculatorScrews or nails for a sheet good on an edge-and-field pattern, with the box count to buy.
- Screw and nail holding strengthWhat a screw, nail or lag holds before it pulls out, by species and by how deep the thread goes.
- Wall framing stud countField studs at 16" or 24" on centre, corner studs, and the king and jack studs every opening adds.