Metallography of 8th / 9th Century Swords and Saxes
|What follows is essentially an
excerpt of Erik Szameit's and Mathias Mehofer's paper entitled (translated to
English) "Technological Investigations of Early Medieval Weapons from
Upper Austria"1). All the
pictures in what follows are (somewhat edited) pictures from this quite
interesting publication in an obscure journal.
The guys investigated these weapons in some detail:
|It's a long paper with
many pictures. Unfortunately the authors did not look into faggoting and
confuse the issue considerably by invoking "carburization" during the
forging many times.
I will only give you the highlights, and I will add my own interpretations of the pictures.
|First some data about the saxes:|
sax (see below): Several slag bands, possibly from a few foldings.
Otherwise not much slag inclusions in in the bulk. High carbon steel for the
edges was joined with low carbon steel for the bulk. Microstructure and
hardness values indicate successful quench hardening of only the edge parts to
extreme hardness values. The weld seam is a bit strange and I don't know what
to make of it except to point out once more that fire welding is a
especially if you can't easily get up to 1200 oC (2192
oF) in your forge hearth, as we assume was the case in days of yore.
This sax is quite comparable to Japanese swords and seems to be similar to the sax from approximately the same time span investigated in some detail by Stefan Maeder .
|Gusen and Enns sax: The pictures tell it all. The construction is similar to the sax above. We have a rather well constructed weapons even so the steel is a bit on the slag-rich side:|
|It is clear that those Austrian smiths and / or their suppliers knew how to select proper grades of carbon steel and how to tell phosphorous steel from carbon steel. The smiths knew a lot about quench hardening and most likely about faggoting, even so we cannot deduce this from the investigations shown here. If they used differential hardening by protecting parts of the blade from cooling too rapidly, i.e. by coating it with mud, cannot be told from the pictures here either.|
|The Swords / Spatha|
|Now to the swords. First the relatively well preserved pattern welded sword from Enns / Lauriacum, from the same burial that also yielded the sax and the lance point. Here is what one gets in about half of a cross-section:|
|A twisted rod texture is visible in
the center. The contrast is supposed to result from a combination of ferritic /
ferritic-pearlitic steel (i.e. low and medium carbon) but I'm pretty sure that
phosphorous was involved (the term "phosphorous" was never mentioned
by the authors).
It appears that just four twisted rods are used for the center of the blade as opposed to four one each side as would be required for the inferred pattern with the typical curlicues only obtainable if the rods are ground down a lot.
Whatever. While the blade might have sported a nice pattern, it was inferior to its sax companion in terms of hardness. Nevertheless, an attempt to have a hard edge was made, and we might simply have lost the real hard edge to corrosion.
|The two remaining swords are not pattern welded but piled without a pattern (edges hard steel, inside softer steel). They are quite interesting because both of them contain remains of a simple inscription that was obtained by hammering a small striped rod into the blade. Here is the one of the St. Georgen spatha:|
|Here is a partial cross-section cutting through the inlay of the St. Georgen spatha:|
|The Schwödiau spatha looks much the same. One might guess in both cases that the striped rod "wire" was just hammered in without making a groove first because the slag trails in the bulk just curve around and are not interrupted.|
|From the picture above it is clear
that quench hardening was applied, producing an extreme hardness of 761 at the
edge of the blade. The body of the blade was quite soft, on the other hand.
Again it appears that the smith knew exactly what he was doing. His raw
materials, however could have been a bit better with respect to the slag
The inlays are significant, I think. They take us right to the famous "+VLFBERH+T swords of chapter 11.4.
|1)||Erik Szameit und Mathias Mehofer: "TECHNOLOGISCHE UNTERSUCHUNGEN AN WAFFEN DES FRÜHMITTELALTERS AUS OBERÖSTERREICH", Jb. Oö. Mus.-Ver. (Oberösterreichischer Musealverein; if you Non-Germans / Austrians can pronounce that you get a free beer!) ), Bd. 147/1, Linz 2002|
Books and Other Major Sources
Critical Museum Guide: Landesmuseum Württemberg; Württemberg State Museum, Stuttgart, Germany
Critical Museum Guide: Museums in Copenhagen
Critical Museum Guide: Landesmuseum Schleswig-Holstein in Schleswig, Germany
Critical Museum Guide: "The Vikings" Special Exhibition from Oct. 2014 - Jan. 2015 in the Martin-Gropius-Bau
Danish Bog Sacrifices
11.4.2 Blades of Viking Era Swords
11.3.3 Evolution of Pattern Welding
Large Pictures 2 - Chapter 11.3
Northern Sword Types of the First Millennium
Making Palmette Patterns
Radiographie Study of Pattern Welded Swords
Old Sagas, Heroes and Swords
Moravian 9th Century Swords
The Anglo-Saxon cemetery at Dover Buckland, Kent, UK and the technology of some of the iron artefacts.
Some Less Important
Maps of Various Cultures
Structure Investigations of Pattern Welded Swords
Wurmbunte Klingen. Studien zu Konstruktion, Herstellung und Wertigkeit der frühmittelalterlichen Spatha in Westfalen
© H. Föll (Iron, Steel and Swords script)