Best research practices in psychology: Illustrating epistemological and pragmatic considerations with the case of relationship science.
Briefly, a date nail is a nail with the date stamped in its head. I concentrate primarily on the nails used by railroads.
Lengths run from a paltry 3/4" up to 3", with shank diameters running from 1/8" up to 5/16".
The nail heads can be round, square, diamond, pentagon as well as other more rare shapes.
Most date nails are steel, though many are copper, aluminum, malleable iron, or brass.