The Screw Threads of Antiquity: To Raise, to Adjust, to Measure, to Press, and to Hold

Abstract

The screw in antiquity took many forms suitable to an equally wide range of functions. Where pressure was to be exerted or a firm union achieved, both male and female screw threads were necessary. These were rarely produced in metal in the remote past. This paper describes a number of Late Roman crossbow brooches with tapering threaded pins and brass demountable lampstands or candelabra where the components were held together by a male screw engaging with the corresponding female screw. The way should have been open for the development of the familiar nut and bolt. Instead the succeeding demountable lampstands were held by much simpler bayonet fitting, and screws and bolts as known today had to wait for another thousand years.