In the United States, some nails are measured in pennies, such as 10-penny, which is written 10d. The penny measurement goes back to the 15 century in England and referred to the price for 100 nails. A nail about 3 inches long would cost 10 pence per hundred. The larger the nail, the higher the price for 100 nails.
The symbol “d” is an abbreviation for denarius, the name of a Romain coin very similar to a penny. refers to the price of one hundred nails in I’ve purchased 10-penny nails, but until today had no clue what the “penny” unit of measuring meant. The term penny size originated in England, but is no longer used there.
|Jancie VanCleave’s Science Through the Ages|