Dating antique chairs
Screws are relative newcomers to the production of furniture, primarily because they are so hard to make by hand.
But as the complexity and sophistication of furniture increased in the late 17th century and the use of brass hardware, locks and concealed hinges became more popular, there was an obvious need for a fastener that could hold two surfaces together without having to penetrate the back surface of the second piece.
Chairs were increasingly made in sets, I comprising both arm and single chairs.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.C., used a shaft with a surrounding spiral in a tube to lift water, making use of one of the basic tools of physics – the ramp.In effect a screw is a ramp wrapped around a column.