# What do pennies measure in a nail?

You often see nails marked in both inches and pennies. What does the penny measure? Is it related to the antiquated unit of pennyweights?

https://en.wikipedia.org/wiki/Nail_(fastener)#United_States_penny_sizes
This may help. More pennies is longer, but no strict correlation.

It’s a measure of how many pennies it costs to get a hundred nails. Or used to cost, like six hundred years ago, in England.

And it was the long hundred (i.e. 120), not our usual 10^2 hundred.
(That is, the hundred in the number of nails, not the hundred in the number of years).

Thanks, Quercus, for the Wikipedia link. Now I know that a 10-penny nail is 3" long.

When I was a boy, a friend played a record of a comedian (Brother Dave something) who had a bit with a glorious bit of language in it. “…I’m gon’ hit you so hard, you’re gonna hum like a ten-penny finishin’ nail been hit by a greasy ball peen hammer.”

I hope I remembered that accurately.

I don’t think finishing nails are sold in penny sizes, just common nails. But I suppose finishin’ nail sounds funnier.

And to make it even more confusing, the “penny size” is designated by a “d”, which is from the Latin “dinarius”. So if you’re looking for 6-penny nails, you look under 6d (not 6p) in the hardware store.

That “d” was the normal abbreviation for “penny/pence” in the sense of coins/money as well, before money was decimalised in the UK. So “6d” in money was half a shilling.

I remember when I was younger, taking a while to work out why a pound of nails was always the same price, regardless of the size.

Emphasis added. When was that? Just wondering.

On Decimal Day.

I still have some boxes of finish nails, bought within the past ten years, that are marked 4d and 5d. From what I see on the Lowes site, they now refer to them only in inches.

Wow… decimal currency and no more rum in the navy, all within a 8 month span.

That same general approach was used for lots of other things back in the day.

A 12 guage shotgun is larger than a 20 guage shotgun. Because you can cast a pound of lead into either 12 larger balls or 20 smaller ones.

Wire gauges are similar.

A 12-count shrimp is bigger than a 20-count shrimp. Same reason.

But shell-packing as a mathematical problem is for different shells.