The item below is from a question/answer column on page 28 of the November 2004 issue of WOOD Magazine. It has some interesting info, but I question its accuracy, in part because the last paragraph makes no sense at all if you do the calculations. (If the last number is a typo (should be 5") and the 16d to 20d is considered a "1d" increment, then it makes sense, but certainly the way it is written leaves a lot to be desired.) Anyone have better info?
How are wood nails classified in metric countries? Simply by style and length? Jim Elwell *************** Q: What is the origin of "penny," the word used to define nail sizes? A: The "d" abbreviation for penny dates back to Roman times and the coin called the denarius. The "penny" system of nail designations, however, stems from the English pence. At no time did a 6d nail cost sixpence, but records showthat 100 6d nails had once cost that amount, and that 100 8d nails had simultaneously cost eightpence. Today, the "d" designation pertains more to length than cost. A 2d nail used with wood measures 1" long. Each 1d increment equals a 1/4" nail-length increase up to 16d. Above 16d, nail length increases come in 1/2" increments. that explains why a 10d nail is 3", and a 20d nail, the next size jump above 16d, measures 4". ***************
