Dating machine cut nails
The cutters had intersecting grooves, which sheared the iron lengthways.
It's impossible to say whether wrought nails were still widely in use after this point in Exeter.
Since the sheared cuts for each nail blank were made from opposite sides of the nail plate, the resulting two burrs are on diagonally opposite comers of the nail blank (see illustration a. Nails thus made until about 1830 are known as "Type A" cut nails. Nail samples from houses in several sites in Massachusetts and New Hampshire with known dates were studied and found to bump nail technology back several years earlier.
During the 1820s, machinery was perfected to speed up nail production and deliver a more consistent product, cutting and heading the nail in a single operation.* The iron nail plates were fed into the clipper as of yore, and the overhead cutter or shear was set diagonally at an angle of 4 to 6 degrees but, with each stroke of the shear, the nail plate was alternately angled from side to side producing the desired tapered blank; or, the plate passed under an indexing cutter head which produced the same result. The large end of the tapered blank was simultaneously upset in a heading machine pro- viding the desired configuration. The slitting mill consisted of two pairs of rolls turned by water wheels.
This was then passed between flat rolls which made it into a thick plate.
it was then passed through the second rolls (known as cutters), which slit it into rods.
The head is usually round or rectangular but sometimes has an off-center notch.
But because of their smooth shape, modern nails have less holding power than hand-forged or cut nails.
To determine if missing nails were antique or if they have been replaced with modern nails, look closely at the shape of the hole and the color of the wood around it.
Around 1880, a machine was invented that produced a round nail drawn from a piece of steel wire and formed with a perfectly circular, stamped head and a sharp, cut point.
Cabinetmakers continued to use cut nails into the start of the 20th century until stockpiles were used up, so you may find either type of nail in furniture between 18.
By 1800-1810, the use of cut nails was widespread in the U. In these early, treadle operated machines, the nail plate itself was turned over after each chop of the overhead shear producing wedge-shaped blanks (see illustration below).