Wire: The Raw Material of Maille
The Technology of Drawing Wire
There is considerable debate surrounding the medieval maille maker’s source of wire. There is no doubt that ancient man knew how to draw metal into wire. Examples of drawn bronze wire and stone draw-plates dating to around 2000 B.C. have been found.(1) There are even Biblical references to wire.(2).
What is in doubt is when man gained the ability to draw iron into wire.
E. Martin Burgess cites several examples to support the drawing of wire in the context of making maille. Among them, an illustration from a Nürnberg craft book dating to 1529 which shows "a long wire being wound from one drum on to another and passing through a multi-hole draw plate fixed between them."(3), another illustration, dating to 1533, depicting "a man drawing wire through a large multi-hole draw plate with large two-handed pliers."(4) and a third illustration, a Dürer watercolor, showing "wire being wound on to a drum of considerable diameter and great length which is being turned by a water wheel."(5)
Dr. Cyril Stanley Smith, in an article replying to Mr. Burgess’ above sited comments on drawing wire, provides evidence to support wire being fabricated by both drawing and by cutting a strip off of a sheet of metal, saying, "The cross sections of most of my European samples had slag distributed in a way that indicated that an approximately circular section had been maintained for some time during the process of reduction, i.e., that the wire had been drawn extensively. The oriental wires, however, all showed evidence of having been cut from sheet or strip, and three of the European ones (Nos. 2, 3, and 5) had been drawn only a little, if at all." He further states, "The European wires may have been drawn through a finishing die, but they had been reduced in cross-sectional area by certainly far less than 50 per cent after the metal had been slit or sheared from a strip. Some of the oriental links showed no distortion whatever of the ends of the fibers, and the metal originally at the corners of the cut rectangular section must have been removed, not compressed inwards. Although it seems surprizing [sic] to us that all wire was not drawn, the evidence on these few links is incontrovertible. It should be recalled that even nails were made by slitting until well into the nineteenth century."(6)
In another of Dr. Smith’s articles, he details his examination of 16 rings from various maille garments of known origin. When speaking of the rings of a 17th century Turkish shirt, he notes that, "...they have slag stringers running nearly parallel to each other right across the wire section, and show unmistakably that the wires had been cut from a thin plate or strip and filed, scraped or abraded to the present shape: they are definitely not made of die-drawn wire."(7)
The earliest of the 16 rings that Dr. Smith examined is from a 14th century European coif. Dr. Smith concludes that this ring was made of drawn wire. The earliest mention of wire drawing as related to armour that I have been able to document is a document, Livre des Metiers, written around 1260 by Etienne Boileau, which mentions two corporations of wire drawers in Paris.(8)
From my reading of the above and other sources, it seems likely that the drawing of iron into wire occurred sometime between the 13th and 15th centuries. However, since maille very much predates this time frame, it seems likely that at least the earliest maille garments were made from iron wire that was not drawn.
What we may deduce from this is that maille was undoubtedly made from both drawn and slit wire. It may also have been made from wire which was formed by simple hammering. We might be tempted to speculate that perhaps maille wire was originally made by "primative" means, being simply cut from sheets of iron, and that as the technology of drawing wire matured, drawn wire may have become more prevalent. This assumption about the evolution of wire manufacture may be incorrect, however, as the 17th century example made of slit wire, described above, might attest. It seems likely that economics dictated what kind of wire would be used. Whatever manufacturing method produced the cheapest, most readily available wire was likely that to which maille maker availed himself.
To read more about wire drawing circa the 12th century, click here.
To read more about wire drawing circa the 16th century, with specific references to drawing iron, click here.
Present wisdom seems to indicate that the raw material for the wire used to make maille was predominantly iron, not steel. Of the 16 rings mentioned previously by Dr. Smith, only 3 of them contained enough carbon to be considered steel.(9) Those three steel rings had also been heat treated to harden them. However, I have doubts as to whether enough maille has survived through the ages, and whether enough chemical analysis has been done on that surviving maille to draw any solid conclusions as to whether iron or steel was the preferred metal for making maille. Nonetheless, most publications on maille today cite iron as the primary material, and Dr. Smith's analysis above would seem to support that idea. So for the present time, I will assume that iron was the predominant metal used to make maille.
The question arises as to whether or not the medieval maille maker intentionally used iron or steel as a raw material. Certainly medieval metal workers have been familiar with the differences between iron and steel since ancient times. Pattern welded swords dating to the second century show that the mechanical properties and benefits of both metals were understood and put to use, making swords that combined both metals to produce one that was both hard enough to hold an edge and yet tough enough to take the abuse of battle. Thus "it was known that steel was a much more versatile material, but its relationship with iron was not understood. It was thought (by Biringuccio for example) that steel was a purer form of iron, and if iron was left within a charcoal hearth for hours, or even days, it was made purer or more ‘steel-like’ by having the impurities burnt out."(10) Though the early medieval smith may not have understood how to make steel, they obviously were able to differentiate between steel and iron. This may have been done by testing various blooms with a chisel to find ones that seemed harder than others, or though spark testing, whereby a piece of metal is held against a grinding wheel, and a judgment made based on the color and shape of the sparks produced.
If indeed the medieval armourer was aware of the differences between iron and steel, why then does it seem that the majority of maille was made from iron, rather than the stronger steel?
It would seem that economics is likely the driving force behind the choice of metals. During the Wallace Collection Arms and Armour Study Day that took place in November of 1999, Dr. Alan Williams presented excellent information that likely has great bearing on the choice of metal for maille making.
Dr. Williams presented data that plotted the size of iron blooms, recovered as archeological finds, against their probable date of origin. What he was able to deduce from this is that there is a definite correlation between the size of the blooms and the economic prosperity of Europe at the time of creation of the bloom.
Thus Dr. Williams was able to explain why it is not until the 14th century that items like one-piece breastplates began to appear in Italy. The reason is that economic conditions did not support the construction of large bloomery furnaces needed to make blooms large enough for such large plates until that time.
According to Dr. Williams, a one meter high furnace approximates 1kg blooms. Furthermore, it takes a ten kilogram bloom to produce a two kilogram plate of steel. The reason for this is because as the plate is heated and worked much of it is lost as scale. Therefore the furnaces producing such large blooms of steel were likely very large, permanent structures, and in fact there are period illustrations of such furnaces much taller than a man.
One of the side-effects to having such a large, tall furnace is that it takes the solid particles iron, carried by molten slag, more time to reach the bottom of the furnace. Consequently, the iron absorbs more carbon than it would in a smaller furnace. Additionally, a larger furnace may burn hotter than a smaller furnace, which again will enhance carbon absorption. To quote Dr. Williams:
"Higher C% is due to both higher temperatures, as you have reaalised, [sic] and, if taller, longer residence time. The particles of solid iron pass down the furnace, absorbing carbon on the way until liquid slag draws them together by surface tension and they sinter into a bloom. The longer they spend sinking downwards, then the higher their C %, and also the lower the Fe % of the slag."
The upshot is that larger furnaces are more likely to produce blooms of steel, rather than iron blooms usually produced by smaller furnaces.
Assuming that this is true, I believe it may help explain why we find most maille to be made of iron. First of all, only small blooms would be needed to make wire. After all, why waste large blooms, that could be used for larger plates, on mere wire? Well, if we accept that the smaller blooms would have been relegated to things like wire, and if we accept that smaller blooms would be the product from smaller furnaces and thus be less likely to be steel, than this might well explain why most mail was made of iron.
Dr. Wiliam’s response to my above theory was simply, "Precisely."
At least some maille garments were case hardened and tempered, for specific mention of this is mentioned in the publication Natural Magick Book XIII, in 1558:
"Take soft iron armour of small price, and put it into a pot, strewing upon it [soot, and organic powders to supply carbon], cover it, and make a good fire about it: then at the time fit, take the pot with iron pinchers; and striking the pot with a hammer, quench the whole herness red hot in water; for so it becomes most hard ... But, lest the rings of a coat of male [maile] should be broken, and flie in pieces, there must be strength added to the hardness. Workmen call it a return. Take it out of the water, shake it up and down in vinegar, that it may be polished and the colour be made perspicuous: then make red hot a plate of iron, and lay [it] upon the same: when it shows an ash colour, cast it again into the water, and that hardness abated, and it will yield to the stroke more easily: so of a base coat of male, you shall have one that will resist all blows."(11)
This suggests that some maille was at least partially converted to steel after assembly, and done so specifically for the mechanical advantages of hardened, but tempered, steel. However, according to Dr. Williams, no armour to date, maille or otherwise, has been analyzed and thought to have been carburized.
Brass and possibly more precious metals were sometimes used to add decorative trim to maille garments, often as edgings.