Jay D. Edwards and Tom Wells, researchers from Louisiana State
University, have published a working paper on historical nail
technology. Their work chronicles the development of nail technology
from 1720 to 1900. The study was undertaken to help historians
pinpoint the precise construction dates of historical buildings.
The authors’ systematic chronological presentation of the
subject includes many photographs and drawings that transform
complicated technological research into an easy to read and understand
They begin by explaining the three ways in which nails are made:
by forging, by cutting, and by drawing. Forged nails are hand
shaped one at a time by a blacksmith. After the shaft is shaped,
it is placed into a heading tool and the head is formed with several
blows of a hammer. This process produces what is commonly called
the Rose Head nail.
Cut nails are made in a two-step process.
- First, blanks are cut from flat strips of iron.
- Second, the nail is held tight while the head is formed by
the blow of a mechanical heading device.
Drawn nails are made by pulling wire through a series of dies.
Die sizes, of course, determines nail size. The wire nail is then
held in a clamp and headed in a separate process. Although drawn
nails were experimented with in France in 1820 and in New York
State in 1855, it was the development of Bessemer steel in 1885
that made the drawn nail feasible.
Edwards and Wells have sorted the many types of nails into twelve
easy to understand groupings.
Groups 1 and 2 are nails made entirely by hand. These nails are
the ones that antique dealers call Rose Head nails. The reason
for dividing handmade nails into two groupings is that two different
forming methods were used. A close inspection of a handmade nail
will often reveal the method used and therefore its approximate
Of the seven remaining groupings, nails in groups three, four,
five, six, and eight are the most common nail used to fasten together
American country and American primitive furniture. These nails
were cut then headed by machines. There are many easy-to-see differences
in each of these five styles. Antique dealers who learn to recognize
these five styles of nails can date country and primitive furniture
to within a twenty-year period and by combining nail technology
with those of hinges, screws, latches, saw marks, and plane marks
can pinpoint the actual construction date to within ten years.
Machinery leaves telltale marks on the piece it makes. In the
case of machine cut nails, the shaft of each nail will exhibit
cutting marks where the nail is stamped out of a sheet of iron
in much the same manner as a cookie cutter works. As the nail
cutter slices through the nail plate it rounds the top face and
leaves a burr on the bottom (or back) of the nail. Nails cut in
this cookie cutter fashion were made from 1790 to 1890.
The first nail making machines were crude and lacked power. The
nail stock had to be turned over because the cutting blades could
only cut one side at a time. This process left a cutting burr
on each side of the nail shaft. Nails with opposite side burrs
were made from 1790 to 1835.
Besides cutting marks, the nail shaft will also exhibit clamp
marks near the head where it was held tightly so that the head
could be formed by a heading machine. Early heading machines grabbed
the nail from the side and left quite a noticeable imprint when
it did so.
After 1835, a new method of heading nails was employed and this
machine grabbed and held the nail on its face leaving a recognizable
indentation on the face. This one bit of information can help
date cupboards to before or after 1835. Typically, side pinched
nails date 1790 to 1835; face pinched nails date 1835 to 1890.
At the other end of this scale is group 10, a square cut steel
nail introduced in 1885 that had a short life span because it
was almost immediately replaced by the wire nail.
Groups 11 and 12 are a detailed examination of the modern wire
nail that came into use in 1880 and by 1900 had displaced the
cut square nail.
Wrought iron has a grain much as wood has a grain. Hand forged
Rose Head nails were made with the grain running lengthwise of
the nail shaft. However, when nails began to be stamped out of
flat sheets of wrought iron, it was found that the cutting machine
did not work well with the in-line grain. Therefore, early machine
cut nails were cut across the grain. This process produced an
inferior nail that could not be clinched but their low cost far
out weighed this disadvantage.
Consequently, from 1790 to 1848 the grain of a machine cut nail
runs across rather than with the length of the shaft. In 1848,
a new machine was introduced that cut nails, once again, in-line
with the grain of wrought iron. This machine was used until steel
replaced wrought iron in 1885.
Using the above information nails can be dated as follows:
- A cut nail made out of steel dates 1885 and later.
- A cut nail that has opposite side (face and back) cutting
burrs, is side pinched, and has a grain that runs across the
shaft dates 1790-1848.
- A nail that has cutting burrs on the same side, is crossed
grained, and side pinched dates 1835-1848.
- A cut nail that has in-line grain, is faced pinched, and cutting
burrs on the same side dates 1848-1885.
There are many other combinations, too many to include in an
article of this nature.