Dating antique chairs
Handmade screws of the 18th century started out much as the handmade nails of the period did, as square iron nail stock produced in a rolling mill.
Today, if you run into these somewhat tall antique chairs you will probably notice that they're not very consistent in the height of the seat.
The screw on the right is a modern gimlet screw, post 1848, with tapered shaft, even threads, pointed tip and centered slot. The handmade nails of the period derived much of their holding power from the ability to drive the nail through two surfaces and bend it over on the back side, i.e. But that solution would not work for securing the top on a chest of drawers or table top without either driving a nail through the top from above or clinching it on the top to hold it fast.
The same problem arose while trying to affix a lock to the back side of a drawer.
Damp floors, wood worms and ill usage have taken their toll on all original sets.
Above is a wonderful example of an antique corner chair which was an English fashion that develop during the first half of the 18th century.