For historical reasons, nails are sold both by a number followed by d and (less confusingly) by length. The “d” stands for penny, so 8d refers to an 8-penny nail, 16d to a 16-penny nail and so on.

We show marking the wide face, which will help you align twisted studs. Tack the pairs of plates together with 8d nails after marking them so they don’t get separated and mixed with other plates.