On Tue, 19 Oct 2004 08:25:58 +0100, Alun Saunders
wrote:

Mark Hopkins wrote:
From this site.....http://www.appaltree.net/aba/nails.htm

We still use the term "penny" when referring to a nail's size. It is
believed that this term came into use in the early 1600's in England. The
English monetary unit was the Pound Sterling (£) which was divided into
Shillings and Pence. The cost of 100 nails in Pence in the 1600's is how we
refer to nail sizes to this day. For example, 100 small nails that sold for
4 pence were called 4d nails (4 d is the abbreviation of 4 pence). 100
larger nails that sold for 16 pence are 16d nails. And so on.

How quaint I (in Ireland) buy nails either in inches, or millimetres!
Makes more sense to me ...

Actually, the current 'd' designation of nails corresponds, according
to current issue of WOOD mag., to length in inches as follows:

1. 2d = 1 in.
2. Each increment adds 1/4 in. up to 16d
3. Above 16d, each increment adds 1/2 in.
4.Note that all numbers dont exist e.g. 20d is next increment above
16d.

Thus a 10 d is 3" and 20d is în.