I’m getting old enough to say: “I’ve forgotten more than you’ll ever know.” I’m sure I knew this once, but what’s the origin of ‘penny’ in nail size designations, and why is it abbreviated ‘d’? How are nail sizes specified where the metric system is used?
Thanks!
Al Mollitor, Sharon MA
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Replies
The way I learned it was that 4d, 6d, 10d etc. were what you'd pay in jolly olde england for a pound of nails.
Mike
That doesn't make sense to me. It would take a lot more effort to make a pound of small nails than a pound of large nails.
I suppose you're right about that. After reading the others, it makes more sense that it would cost 4d, 6d or whatever per hundred, not per pound.
penny comes from pennyweight, how many nails of a certain size weigh a certain amount.
Incidentally, in the maritimes of canada, I have never seen nails referred to by pennyweights. everything is purely length. I'm amazed that the pennyweight designation still exists at all.
Actually, I believe this a corruption that has gained a lot of traction through the retelling.
A Pennyweight is a unit of measure in the old Troy system, approximately 1½ g. (someone can look it up if they want to let us know exactly) - but it has nothing to do with nails. The British monetary system contains the pound ( £ ) and the penny ( d ). While both symbols do have a tie-back to the Troy measurement system, a 10d nail means that 100 of them could for 10d. Now why, you may ask, did they get frozen in value ? It's because during the period of history when the barter system was being replaced by the monetary system, but coins were still in short supply; there was an ad-hoc hybrid system where, for example, a carpenter could exchange 6d worth of nails for a 6d tankard of ale and the values became ritualized and fixed even though 6d worth of nails may really have cost 9d.
PS, you probably won't find this answer in te following excerpt, but it's interest reading none-the-less. http://www.geolib.com/smith.adam/won1-04.html.
Phill Giles
The Unionville Woodwright
Unionville, Ontario
-penny
an ending added to a number to indicate the size of a nail, as in "sixpenny nail" or "tenpenny nail." It's not clear exactly how this terminology began, although the usual guess is that tenpenny nails originally cost ten pence per hundred. There is, very roughly, a linear relation between the size designations and length: an n-penny nail is roughly (1/2) + (1/4)n inches long. This makes the tenpenny nail about 3 inches long, the eightpenny about 2.5 inches, and so on.
pennyweight (dwt or pwt)
a unit of weight in the traditional troy system (see also pound [2]), equal to 24 grains or 1/20 troy ounce . One pennyweight is approximately 1.5552 gram. The d in the traditional symbol dwt is from the Latin word denarius for the small coin which was the Roman equivalent of a penny. (The letter d is also the traditional symbol for the penny in the English monetary system.) See troy weights for additional information.
from: http://www.unc.edu/~rowlett/units/dictP.html
For a little anthro on how to identify the type of nails in historic buildings:
http://www.anthro.utah.edu/IMACs/470-Nails.pdf
Yeah, the 1 penny = 1/4" in length works fine from 3d (1+1/4") through 10d (3"), but then things get strange again as a 12d measures 3+1/4" (following the 1d=1/4" formula it would be 3+1/2") and a 16d measures 3+1/2" - go figure.
All that is not to be confused with sinkers, which have been in widespread use here on the left coast since at least the mid 70s when I came out here. These sinkers are vinal coated and for some reason have a length system all their own. 8d sinkers measure 2+1/2", for example, but 16d sinkers only measure 3+1/4", which to me should make them 12s, but they aren't, they're 16s. If anyone can explain that one, I'm all ears.
Now, as to henways...
May be wrong, but recall that sinkers began after kegs from Japan quit saying made in "occupied" Japan, so could be a tie-in there. Con-current was Wyerhauser leading the conversion from 1-5/8 to 1-1/2 lumber thickness, so the nails had to be shorter to not poke thru when driven at 10 deg off vertical <G>. Begs another question, why not 3" long??
"Begs another question, why not 3" long??"
That is what framers use for wall framing in these parts, 10ds, for that very reason, Art.
If your question was serious, I'd have to say that it wasn't all that long ago framing lumber was 1+5/8" thick, like you stated earlier. So 2 plates would add up to 3+1/4" and a 16d wouldn't poke through unless the lumber was perfectly dry, and perfectly milled and the nail was driven perfectly perpendicular.
I've heard of inspectors who demanded to see the tips of nails projecting through the bottom of the bottom top plate (what I'd call the "top plate") so they knew you were using 16s, but I learned to always nail the double top plate directly over studs so the electricians and plumbers wouldn't hit nails with their drill bits. Guess I've been lucky and never run into an inspector like that.
Edited 10/18/2003 4:36:17 PM ET by jim blodgett
The use of Penny in nail sizes is from the old British system based on the cost in "pennies" of 100 nails. "d" being the British symbol for penny -- from the Latin "denaius". This dates from at least the 15th century when all nails were hand made from wrought iron.
deblacksmith
Well, it's already been said but I thought I would offer another "official" voice to the discussion. According to my Thomas J. Glover Pocket Reference (Third Edition - ISBN 1-885071-33-7),
"The "d" listed after each Size Number stands for "penny", which was origionally used in old England as a way of describing the number of pennies needed to buy 100 nails. Today, "penny" is used only to define the length of the nail."
However, I've also seen 3 1/4" nails marketed as 16d's. According to the charts in my reference, all 16d's should be 3 1/2". I suspect the shorter 16d's are marketed as such because they have an 8 gauge shank rather than the 9 gauge shank common on 12d's.
One thing is clear... at those prices, they dang sure weren't marketing stainless ringshanks to fit my nail gun when they established this convention back in old England!
Kevin Halliburton
"I believe that architecture is a pragmatic art. To become art it must be built on a foundation of necessity." - I.M. Pei -