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?

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.