Theophilus was a monk who, during the mid 12th century, wrote a text attempting to document the trades of painting, glassmaking, and metalworking. Thus the following descriptions can be held as relevant to the 12th century.
Hawthorne, John G. & Smith, Cyril Stanley. Theophilus: On Divers Arts - The Foremost Medieval Treatis on Painting, Glassmaking, and Metalwork. Dover Publications, Inc.: New York 1979. ISBN 0-486-23784-2 pages 87-89
Chapter 8. Iron [Plates] through Which Wires Are Drawn
Two iron [plates] three fingers wide, narrow atthe top and bottom,’ thin throughout and pierced with three or four rows of holes [of diminishing size] through which wires may be drawn.2
2 This description of the drawplate provides the first definite record of wire.drawing, although wire of precious metals and bronze was extensively used in jewelry and other applications for at least 3,000 years before Theophilus. It is tempting to believe that the long lengths of wire must have been drawn through a die, but there is no real evidence of this. The cutting of strip followed by rounding. under the hammer would not be too difficult an operation, and, indeed, shapes such as the Etruscan safety pins in which the wire is integral with a large body could only have been made this way.
The most famous wire in antiquity is that made by Vulcan by an unspecified technique to catch Venus and her paramour. An early reference is in the Bible (Exod. 39), where "twisted chains like cords" of gold were used on a breastpiece of Aaron’s ritual garment and also "gold leaf was hammered out and cut into threads to work into the blue and purple and the scarlet stuff, and into the fine twined linen in skilled design."
Hardwood slabs with holes drilled in them are known from fairly remote antiquity, and these seem to have been intended for scraping soft organic materials. In 111-62, Theophilus mentions the use of such a wooden die for smoothing out a braided cable. Such dies may have been used quite early for compacting rolled-up metal sheet and perhaps even for giving a smooth round and uniform surface to hammered wire of soft metal. It is not impossible that this led directly to the use of a sequence of holes of decreasing diameter for the true drawing of soft metals, with considerable reduction in area and increase in length. Another procedure which was in use in Africa even in comparatively modern times was the reduction of hammered bars by pure tension. A drawing of A.D. 1389 in the Mendel Brothers’ Hausbucb does show wire being treated apparently by merely winding under tension from one block to another, but this is probably the product of an unobservant artist, and, in any case, the method cannot be used for continued reduction, even with intermediate annealing, because any local thinness becomes exaggerated and leads to local failure.
The existence of mail armor is often said to prove the existence of wire-drawing. Quite to the contrary, however, all early mail and even some of late date is unmistakably made from strip cut from hammered sheet, and a satisfactory technique for drawing wire of a hard metal was obviously slow to develop (Smith, 1959). There are a number of fourteenth-century references to wire-drawers’ guilds and the like, and some excellent sixteenth-century drawings of wire-drawing equipment. The earliest illustration in a printed book is in 1530 in Pantheo’s Voarchadumia (Taylor, 1954), which has a woodcut showing the drawing of a coinage strip through a rectangular die, but the artist seems to have confused the windlass of the draw bench with the hand-operated tolling mill of the competitive process. Biringuccio (1540) has woodcuts showing three different hand-operated devices for drawing soft metal wire of different diameters, and a large water-powered crank-and-tongs machine. In the course of his detailed description of the operation, Biringuccio remarks that the drawing of heavy iron wire needs water power, from which it may be concluded that drawn wire for mail was indeed impractical prior to the development of the water wheel and its attendant machinery.
The fact that Theophilus describes the drawplate without bothering to describe its use suggests that it was too well known to need details. This is unfortunate, for his specification of a thin plate narrowed at top and bottom does not conform to later convention.
There is no satisfactory history of the origin and development of wire-drawing, despite its central importance among metalworking processes. This note is based partly on a private communication from F. C. Thompson. See also F. C. Thompson (1935, pp. 159— 62); Lewis (1942, pp. 15—23, 26—27, 56—60); Feldhaus (1914, pp. 199—203); Theobald (1933, pp. 275—79); and Oddy (1977).