When a rotted or mechanically damaged tie was removed, the date on the nail was noted.Ties were never removed because of age, so date nails did not tell section foremen when to replace ties.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.To buy or trade nails, join the Texas Date Nail Collectors Association (see below) or subscribe to the e-mail newsletter Nail Notes (it's free: see below). If you like shiny new looking nails, let them sit overnight in a jar of vinegar.You will come in contact with other collectors this way. There are about 190 members of the TDNCA, and subscribers to my Nail Notes, most of whom are NOT in the TDNCA, number over 180. Don't use any really abrasive method of cleaning, like sandblasting or muriatic acid, and don't paint, varnish, or plate your nails.
In some locations it is handy to drag a powerful magnet through the cinders or to use a metal detector to find these elusive steel gems. Some collectors prefer nails with that rusty patina.
There are over 2,000 different date nails used by North American railroads that show the year.
Add to that the nails which, tell wood, treatment, and other information, and toss in all date nails used in poles and other timbers, and the total number of different nails from this continent easily exceeds 3,500.
Briefly, a date nail is a nail with the date stamped in its head. Most date nails are steel, though many are copper, aluminum, malleable iron or brass.
Date nails were driven into railroad ties, bridge timbers, utility poles, mine props and other wooden structures for record keeping purposes.