Why are steel nails measured in ';penny'; increments and how did this measurement system come about?

It origally refered to how much the nails weighed (16 penny nail weighed the same as 16 pennies)


Nowadays it refers to lenghth.


16d penny nail is 3 1/2';


10d=3';


8d=2 1/2';


6d=2';Why are steel nails measured in ';penny'; increments and how did this measurement system come about?
In the US, the length of a nail is designated by its penny size. It is commonly believed that the origin of the term ';penny'; in relation to nail size is based on the old custom in England of selling nails by the hundred. A hundred nails that sold for six pence were ';six penny'; nails. The larger the nail, the more a hundred nails would cost. Thus the larger nails have a larger number for its penny size.





The penny size is written with a number and the abbreviation d for penny (e.g. - 10d). D is an abbreviation for denarius, a Roman coin similar to a penny.





3d - 1-1/4'; (~30 mm)


4d - 1-1/2 (~40 mm)


6d - 2'; (~50 mm)


8d - 2-1/2'; (~65 mm)


10d - 3'; (~75 mm)


12d - 3-1/4'; (~80 mm)


16d - 3-1/2'; (~90 mm)


20d - 4'; (~100 mm)


40d - 5'; (~125 mm)


60d - 6'; (~150 mm)Why are steel nails measured in ';penny'; increments and how did this measurement system come about?
as Wayne stated.
if its in america its because americans have to be different even if it means being stupid