Dating old nails
By the early 1920's, however, most of these railroads had returned to the practice of placing nails in every treated tie.
Each railroad conducted its own experiments, so the nails used on one railroad will not be like those on other lines.
There is a standard notation to describe date nails.
The 18 pictured above is: 2 1/2 x 1/4 rnd I stl (07) 18.
Briefly, a date nail is a nail with the date stamped in its head. I concentrate primarily on the nails used by railroads.
It indicates that the nail was made by American Steel & Wire Co.Over 2,000 different date nails were used by North American railroads which 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. This one was manufactured to be 2 1/2" long (it was cut a little short), and is made from steel wire 1/4" in diameter. Note the crude, somewhat faint diamond on the shank to the left of the anchor markings.Go to the Photo Album for more pics of nails in ties.Date nails were manufactured by steel companies on high speed machines, even in the early years.