When shopping for nails, there is a lot to keep in mind. Do you want stainless steel nails or copper nails? What grade of corrosion resistant nails do you need? These questions are only the beginning! Then, you come across nails being described with "penny" or "penny weight" and it adds yet another thing to decipher. Don't worry, we are here to help you understand it all!
What is a “Penny” or “Penny Weight” mean?
Get ready for a quick history lesson! The"penny weight" of a nail refers to the price for a hundred nails in 15th century England. The larger the nail, the more "pennies" that would have been required to purchase 100 of them. At that time, 240 pennies equaled a one-pound sterling. Today, we have converted pennies into the length of the nail.
While we no longer pay pennies for nails (unfortunately!) we still use the term. Today, the penny weight is most commonly used to refer to the length of a nail instead of the price.The symbol for penny weight is "d." This comes from the Latin word "denarius", and is loosely translated as coin or penny. It's worth noting that this is only used in American-made nails, not those from Canada or Great Britain.
We're finished with our history lesson, and moving on to a bit of math. A 2d (penny) finishing nail is 1-inch long. Each 1d is assumed to be an increase of 1/4" of length. A 2d nail is 1 inch long and a 3d nail is 1.25 inches long. This is true up to a 16d (3 1/2"). After 16d, nails jump to 20d (4") and increase in length by 1/2" by multiples of 10 (20d, 30d, 40d, and so on.)
As complicated as this may seem, the penny weight/length is not the same for all nails and they are not uniformly used by all manufacturers. This is why to avoid confusion, many experts feel it is best to call for a nail by the length and diameter instead of the penny weight.
Reach out to Fastener USA with Questions
When looking at nail sizes, the “d” stands for penny. As a quick example, 2d refers to a 2-penny nail, 8d to an 8-penny nail, and so on. To put it as plainly as possible, it is a way to indicate nail length. If you're still not quite sure, that is okay! We encourage you to reach out to our team of experts and ask any additional questions you may still have. Send us a quick note and we'll get back to you as quickly as possible!