EARLY IRON

The network for early iron technology

The manufacture of chain-mail

Arne Jouttijärvi, Copenhagen Chain-mail is known in Europe as far backas around 300 BC. The method ofmanufacture is believed to have beendiscovered by the Celts, but the oldestremains discovered (in Denmark) are fromthe Hjortespring find on the island of Als,dated to around 350 BC (Rosenberg1937). This find was excavated by GustavRosenberg in 1921-22 and today, there isalmost nothing remaining of the materialdeemed to be chain-mail. Rosenbergdescribes several square meters coveredwith heavily corroded material. But there isdoubt as to whether this was chain-mail, ora layer of natural iron separation formedaround plant roots, the occurrence ofwhich can often be in the form of rings.The Romans adopted shirts of mail andthey were subsequently used throughoutthe Middle Ages (Blair 1972:19ff,Robinson 1974:154) most often in the 12thand 13th centuries but small pieces of mailwere used right up until the 17th centuryas a part of armor. Although shirts ofchain-mail were used for nearly 2000years, there has been surprisingly littleinterest in the manufacture of them. Sincethey are a very fine and without doubt ahighly specialized craft, carried out over avery long period of time, they are anexcellent object for studying technologicaldevelopment from the Iron Age to theMiddle Ages.

The construction of chain-mailA shirt of mail is a form of armor, made upof rings. As the rings can move in relationto each other mail is far more supple in

relation to plate armor. Chain-mail is alsolighter – the almost complete shirt fromVimose, displayed in the Danish NationalMuseum weighs only 8 kg. But a shirt ofmail represents much more work than sheetarmor, such as the well-known ‘Loricasegmentata’. In the Roman army, only thebetter-off legionnaires were able to afford ashirt of mail (Robinson 1975:164). We donot know how long it took to

Fig. 1

Typical chain-mail construction. Rowsconsisting of jointless rings alternatingwith rows of riveted rings. Each rivetedring connects four jointless rings.

make a shirt of mail. In medieval Germanguild books we can see that a mail-maker’smasterpiece was a shirt that would takehim 6 months.Common to all the types studied is thatthey consist of two ring types (1). The firstis made of a wire that is bent, overlapped

and connected using a rivet. The other hasno visible joint. The two types alwaysalternate in rows allowing each riveted ringto hold four jointless rings. Fig 1.

Ring size and appearanceIn the four types of chain-mail studied, ringsize varies greatly. The finest were foundat Hedegaard, the rings of which had adiameter of around 5 mm and a wirethickness of around 0.95 mm. Somewhatpoorer is the Brokbaer shirt, with a ringdiameter of around 7.2 mm and a wirethickness of around 1.0 mm. A shirt withvery similar rings was found at Vimose(Engelhardt 1869:12). The biggest mailrings were discovered at Vimose andThorsbjerg: 10.5 mm and 12.5 mmrespectively, with wire thicknesses ofapprox. 1.5 and 1.7 mm (Engelhardt1863:59; 1869:12).Corrosion to the shirts from Hedegaardand Kastenskov has caused the rings toswell, making it difficult establish theoriginal thickness. The Brokbaer shirt isalso heavily corroded, but it is possible tosee that the jointless ring had a flat side intowards the hole and a more roundedexterior. The clearest cross-section of thejointless ring can be seen on the shirts fromVimose and Thorsbjerg. Once again, theinside is flat and the exterior more roundedand a groove can be seen all the way roundon one side of the rings. On the smallVimose shirt, the edges of the grooveactually form burrs of 0.5 – 1.0 mm.The cross-section of the riveted rings is inevery case more rounded, although thewire thickness can vary. These rings arenot as uniform as the jointless rings, buthave a tendency to be oval and with muchgreater variation. The overlap at the rivetis always flattened, but least on theBrokbaer shirt, where only a canted cut isapparent with an overlap of 1.5 – 2.0 mm.

The biggest overlap is found on theVimose shirt, where there is up to 7.0 – 8.0mm and on the same shirt, the overlapconsistently follows the same direction,Fig. 2.The rivet heads are nicely rounded incontrast to the rivets used in some casesfor repairs where hammer marks can beclearly seen on the rivet heads.

Metallurgical studyThe jointless rings: A plane-section wasmade across the jointless rings and a seriesof cross-sections of the wire were taken(2). The plane-sections showed that therings are made of carbon-free iron. Only afew rings from the Thorsbjerg shirt werefound to contain up to 0.3% carbon. Theiron is generally quite homogenous andcontains almost no slag – in other words, itis high quality. The rings of the Hedegaardshirt contain 0.2% phosphor. There is nosign of weld joints, which may be expectedif the rings were made of wire bent into aring shape and then welded.

Fig. 2

The overlap of the riveted ends differs,from 1.5 – 2.0 mm to 7.0 – 8.0 mm. Theoverlap is always in the same directionwithin the same mail-shirt, but can be bothways.

Fig. 3

Plane-sections of jointless and rivetedrings show different slag structures. Theorigin of the jointless ring structure is bestexplained by theorizing that these ringswere cut from a thin iron sheet. If they hadbeen formed by drawn wire, the structurewould be similar to the form found inriveted rings.

Some hint of the method of manufacturecan be gleaned from the characteristic slagpattern, which runs in parallel bandsregardless of the rounded shape of thering. A slag pattern of this nature can onlyoccur if the ring is made of a thin, beatensheet and not if the ring (as previouslyassumed) was made of welded wire. Fig3a.Cross-sections of the whole ring also showa very characteristic slag pattern. Thestructure is clearly deformed, as thematerial has been forcibly depressed at thesides. This explains the burrs that evenwith the naked eye can be seen on many ofthe rings. These are the remains of groovessuch as those that can still be found on thesmall Vimose mail shirt. On the rings of theThorsbjerg shirt, the large Vimose shirtand possibly the Brokaer shirt, the grooveon the inside of the rings is very visiblewhilst the outside is more rounded. Only atrace of an outer groove can be seen.The riveted rings: A horizontal section ofthe rings shows that they are also made ofcarbon-free iron. The phosphor content inthe Hedegaard shirt rings is 0.1 – 0.2%.

Fig. 4

A cross-section of jointless rings shows atypical deformed structure where thematerial at the sides has been forceddownwards (a). In some mail-shirts theoutside of the rings are rounded, probablyby deliberate grinding in order to removesharp edges (b).

The riveted rings have an entirely differentslag pattern to the jointless rings: The slagpattern runs parallel with the surface of thering. Cross-sections reveal no depressedstructure.

The manufacture of the ringsThe observations noted here can beinterpreted as follows:The jointless rings: The raw material usedfor the rings was a 1.0 – 2.0 mm thicksheet of almost carbon-free iron. The ringswere either produced using a singlestamping process or in two steps, usinghollow punches. Stamping would seem tobe the most logical process for themanufacture of very large numbers ofuniform rings, but a stamping tool musthave been difficult to produce given thetechnology of the time. The individualcomponents of the tool must have beenexactly the same size and the upper partmust be placed accurately in relation to thelower in order to avoid damaging the toolitself. Additionally, the newly stamped ringcould get stuck in the tool. Today, they are

Fig. 5

The rings can be formed either by astamping machine or by first punching theouter rim and the hole with hollowpunches.

pushed out using powerful springs butsuch things would not have been availablearound the year 0.Bjarne Lønborg, of the City of OdenseMuseums has therefore suggested thathollow punches have been used (personalopinion). Such punches were used in theIron Age for the preparation of variousmetals – although not iron. But since pureiron is soft, in fact, softer than bronze, it iscertainly possible that it can be cut withpunches made of steel. The rings couldthen have been ground after punchingwhich would explain the rounded exterior.This would be done to remove abrasionsand sharp edges, which could otherwisewear through a leather vest wornunderneath – not to mention the wearer’sown skin. Grinding could have beenachieved in the way described by a Germanhandwritten text from the 15th century.The riveted rings: The round cross-sectionof the wire and slag pattern indicates thewire was drawn. This involves first forgingthe iron into a thin rod which is then drawnthrough a series of holes of decreasing sizein a steel plate until the desired thickness isachieved. This is still the most commonmethod used today. Wire making is a very

Fig. 6

A ringmaker finishing rings. The rings arestrung on the bowstring and then drawnthrough a hole in a wooden block.Grinding media may have been added tothe block (Treue 1965).

old technology and has been known in theMiddle East since around 1000 BC. It ispresumed that drawing plates from theEuropean Iron Age could only have beenapplied to silver, gold and copper(Johansen 1953:172). But wire could alsobe drawn from pure, soft iron. The wirewas wound around a dowel and cut intorings. The ends of the rings were laid overeach other, pressed flat and a rivet holemade with a sharp implement. This wasonly done once the ring had been passedthrough its four jointless ‘neighbors’.Finally, the rivet wire would be passedthrough the hole and the rivet head formed.Another common method of wireproduction was cutting, in which a verythin plate was forged and then using tinshears to cut a narrow band off the edge.This gave the wire a slanted cross-section.

Fig. 7The mean value of slag inclusion analyses from the Hedegaard chain-mail comparedwith reference analyses (mean value with confidence limits between 66% and 95%) fromthe eight main areas (I-VIII). The phosphorous-oxide (P205), calcium-oxide (CaO),Aluminium-oxide (A1203) and potassium-oxide (K20) content shows that the origin of theiron must be sought within the area VII – although area III cannot be excluded.

Repairs to mail-shirts were made usingrings made of cut wire. Perhaps they werecarried out by a local smith who did nothave the necessary equipment to drawwire. Cutting would also have been a muchquicker and easier way of making all thesmall lengths of wire needed for repairs.

Fig. 8

The mail-maker at his workbench. He isusing a pair of tongs, probably for riveting(Treue 1965).

These various operations were probablyperformed with special tongs. Noarcheological find known has included anytype of riveting tool or a chain-mail toolfor that matter. A German Medievalhandwritten text shows a ringmaker usingtongs for riveting. The rivets were alwaysmade of cut wire, often with a much

Fig. 9

Based on bloomery slag analyses,Northern Europe may be divided into eightmain areas, each having its own uniquechemical characteristics.

smaller dimension than the rivet hole. They must have been relatively weak jointsand only the riveted rings have beenrepaired. But since most of the strainwould be distributed over a large numberof rings, the strength of the joints wasusually sufficient.

Hedegaard mail-shirt’s originsBy analyzing the tiny elements of slagembedded in the iron, it is possible to givea well-substantiated estimation of whichgeographic area the iron originates from(3). A slag inclusion analysis of the rings inthe Hedegaard mail shirt shows that theycontain so much phosphor that theScandinavian peninsular and the south of –

Germany can be ruled out. The low CaOcontent also rules out the eastern part ofDenmark and the Baltic Sea coastline, Theanalyses match best the north of Germany(VII), but the west of Jutland cannot beexcluded. Fig 7.It can seem surprising the rings in this shirtoriginate from Germany and not the Celticareas. The Germanic peoples aretraditionally regarded as not being inpossession of sufficiently advancedtechnology and organization to be able toproduce such specialized handiwork of thistype. But it could be that our view of thesomewhat technologically-backwardGermans should be revised. If so, it couldbe imagined that even advanced technologyhas been known in the Germanic areas,perhaps in connection with centers ofwealth and power such as around Gudme.

ConclusionDespite the provisional character of thisstudy, some conclusions can be drawn. Thecraftsmanship of mail-making was veryspecialized, performed in specialworkshops. We can imagine these as beingpart of a more extensive‘arms-manufacturer’. The tools andexpertise used was not available at thelocal smithy. In previous studies and in anumber of archeological publications(Drescher 1981:186) the jointless rings areoften described as being welded. Ringsmanufactured by welding the ends of a bentpiece of wire have not yet been seen in theDanish material.Welding of wire only millimeters thick is adifficult job, as the heat in such smallpieces of metal is hard to control. It tendsto recede very quickly when the object isremoved from the fire.An essential requirement for the jointlessrings was that they had to be quicker andeasier to manufacture than the riveted ones

otherwise, all rings would be riveted. Suchmail only appears first in the Middle Ages.This makes stamping or punching morelogical. The forging of thin sheets wouldbe no problem for an experienced smithand stamping would be much quicker andeasier than drawing wire followed bywelding.

Notes(1) This article is based on a study of twomail shirts: The first from the pre-RomanIron Age from the burial site at Hedegaard(HOM 151x1054) and the second fromBrokaer (ASR C 3281) dated to the lateRoman period. The studies were latersupplemented by material from the finds atthe Thorsbjerg (NM 19503) Vimose (NM24219) and Kastenskov (NM C 13527)bogs.(2) Samples for metallurgical analysis weretaken from the Hedegaard and Brokaermail shirts supplemented by loose ringsfrom Thorsbjerg and Vimose, Since thereare a lot of common features, despite thedifferent dimensions of the rings, theresults of the study are therefore describedin general terms.(3) A method developed over recent yearsby the author of this article.

SummaryPieces from five different mail-shirts havebeen examined, all dating to the Latepre-Roman Iron Age and the Roman IronAge. These finds include one from a Latepre-Roman burial at Hedegaard in centralJutland, two bog finds from Vimose inFunen, and from Thorsbjerg in southJutland, and from a find in Brokaer nearRibe in western Jutland.The mail-shirts all consist of alternatingrows of riveted, and apparently jointlessrings. The sizes of the rings, however, arevery different, ranging from 5.0 mm to

12.5 mm in outer diameter. Thewire-thickness is 0.95 mm to 1.7 mm. Cross-sections of the wire show that thejointless rings have a flat inside and a morerounded outer side. A characteristicgroove is seen running around the lwerside of the rings, its edges sometimesforming burrs up to 1 mm wide. Thestructure of the jointless rings has beenheavily deformed, the material being forceddownwards at the inner and outer edges. No sign of any joint has been seen in theplane-sections of these rings. The slagpattern indicates that the rings were cutfrom a piece of sheet-iron. Punchingseems to be an obvious method for makinglarge numbers of identical rings. Thepunching might have been done by using aone-step punching machine or, more likely,two different sizes of hollow-punches. Earlier examinations, and thearchaeological literature often explains thejointless rings as having been made bywelding. This has not yet been found inthe Danish material, and since welding isnot easier than riveting, this method couldnot have been as advantageous aspunching. The rounded outside of therings might have been deliberately made bygrinding. This removed the burrs andwould have protected an underlying leathergarment. Riveted rings are made of almostcircular wires. The slag-pattern in theplane-sections are more or less parallel tothe surface of the wire. This suggests thatdrawn wire has been used. The overlap atthe rivets is always somewhat flattened andvaries in size from 1.5–2.0 mm to 7.0-8.0mm. Consequently, the overlap is in thesame direction within one mail-shirt, butcan vary in different mail-shirts. Wire cutfrom sheet-iron was only seen in ringsinserted as repairs. All of the rivets seemto have been made of cut-iron wire. Theriveting might have been done with special

tongs.Analyses of the slag inclusions in the ringsin the mail-shirt from Hedegaard,compared with analyses of bloomery slags,has given information as to the origin ofthe iron. The iron has apparently beenproduced within the geographical areawhich covers the middle part of Germanyand the southern part of Poland.

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