Quality of Iron/Steel in Viking Age vs Later Middle Ages

[Blake Davidson]

Greetings, everyone. This is my first post here. I joined because I'm a history major with a fascination with metalwork and because I plan on trying my hand at bladesmithing beginning around December/January. I'm also a little bit of a fanboy when it comes to some of the members here. I was inspired by a few of them. So I'm quite happy that I finally decided to join the forums. However, because I'm not even a beginner smith yet, I'll probably mostly be reading what the rest of you have to say and learning what I can for the time being.

 

That said, I do have some questions on some of the historical aspects of bladesmithing. I did a number of searches on the forum to make sure this subject hasn't been covered too extensively. I only wanted to make a new thread as a last resort, but I feel it's necessary if I want my questions answered. My questions deal primarily with the quality of the iron and steel used in blades during the Viking Age as opposed to the later Middle Ages. I was considering covering this subject for senior seminar, as this is my last semester of college. But the few sources I was able to find in my university's library and online databases that mentioned the subject at all were written during a time in which the historical narrative was not quite as objective as it is today (though it's still not perfect or even consistent by any means). So I probably won't be covering that topic for my class, but it still interests me enough that I hope some of the members here who are knowledgeable on the subject might chime in with whatever information they can provide.

 

So, something that piqued my curiosity was one of the constants I found in the aforementioned books as well as various places online that discuss older forms of weaponry. It was the idea that the iron and steel from blooms in the Viking Age, as well as construction methods, were somehow overwhelmingly inferior to those in the later Middle Ages. I think it's natural to assume that metallurgical knowledge would progress as time goes on, but I don't know if it really increased so greatly between these two time periods. As I currently understand it, smiths of the Viking Age were aware of the benefits of quench hardening and perhaps even tempering. If I'm correct, weapons in the later Viking Age also began to be made less from pattern-welded steel and more from a single type that would allow for more consistent and controllable production of weapons. This is where the whole "Superior/Inferior" thing starts to come into play. The ideas presented in those books and websites noted that a single type of steel yielded better weapons in the later Middle Ages as this type of weapon production replaced pattern-welding altogether. However, that doesn't seem to me like it would yield better weapons as much as something of a more consistent quality. I understand that swords of the Viking Age had a wide range of quality where construction and material was concerned. That makes it difficult to make any sort of generalization about them in that regard. But with one type of steel being used, it does seem that more control could be had over the production processes which could lead to a better understanding about that one type of steel.

 

With that said, would I be somewhere MAYBE close to correct in saying that the quality of steel and iron used for weapons wasn't necessarily "better" in the later Middle Ages, but rather more consistent? I understand that what makes a quality sword or spear is more complicated than just the steel that goes into it. And I hope I don't come off as one of those people who argue that one type of sword is better than another for whatever reason. It's just something I'm very interested in.

 

I apologize for the rather lengthy first post. This is just something I've been trying to get a better understanding of and I think many of the members here could chime in and help me understand this a little better. Especially those who have handled older weapons or have studied older methods of smelting ore and crafting weapons. I would also like to leave out too much discussion of Ulfberht blades and the Wootz that was used to create them if at all possible. I'm more concerned with the more common steels and irons used. I look forward to your posts and to a long, enjoyable experience here on the forums.

[Richard Furrer]

Not wootz in ULF blades, but slag free steel. Crucible method being the most likely origin for this. All wootz is crucible steel, but not all crucible steel is wootz.

 

It is a bit more simple than you put forth Blake.

In the end one can say this for sure:

If one had money one got good weapons...this is true of all time periods and all materials.

 

 

There is no inherent benefit to one steel over another when speaking of these methods of production as the human condition...we being soft and squishy has not changed since the stone age AND good material can be made bad in the hands of some.

The reverse is true as well....A good smith in tune with his materials can make a good blade from rather poor starting stock...be that pattern-welded or large refined pieces.

 

It is nice to think that technology marches on and improves with time, but this is not necessarily the case.

It can be said that as large bits of steel were available the necessity to weld up smaller bits to make them large was put asside. With that went the added "Warrior Bling" and smith's showing off which is what much of the pattern-welding was. It did a few other things as well structurally depending upon raw material quality, but once steel was understood it mostly just made an object prettier.

 

I suggest the work of Dr. Alan Wiliams and his volumes on the sword and knightly armor.

 

If you want to see how good swords of various methods/times could be one needs to look at those made for the very rich...they had folk around who would judge quality and as such the blades and armor tended toward the better to best. The commoner got the common stuff.

Ric

[Blake Davidson]

Thank you for the clarification on Ulfberht swords, Ric. I suppose I sound like the newbie I am.

 

I think I probably complicate things more than most because I'm a history major. The one thing that has constantly been hammered into my head is that I'm supposed to "challenge the historical narrative" of years past to paint a more complete picture. I also appreciate the material you recommended. I'll do a search straight away. Thanks!

[Darrell @ warehamforge.ca]

Happy that Ric came in here

 

Lee Sauder has been working quite a bit with a 'hearth' steel making process. This uses a modified forge set up, and allows a smith to re-process some iron material to both remove impurities and also to modify the carbon content.

 

Tim Young had told us about some finds in Viking Age Dublin that suggest some version of this method was known and used by the Norse.

 

This is different than the true Wootz / Crucible process. In the hearth steel, there is no actual container used (a crucible). It is more like a the 'Aristotle' furnace, save it uses a wider and shallower construction. Imagine slightly squashing a deep salad bowl to make an oval shape. Charcoal fuel of course.

 

Not sure if Lee has documented this on his web site (www.leesauder.com).

With luck he will chime in here (seeing his name taken yet again...)

 

Darrell

[Doug Lester]

I can't add much to what has been said above except good luck. Finding old papers and books that discuss iron/steel making from this time can be hard work and expensive. The one book that I have cost me over $100 and came from a bookstore in Denmark (yes, it was in English) and discussed slag more than it did steel.

 

I would really go with Ric's idea of comparing the best swords from these eras because it seems like there were far more difference between blades within than between these periods. Not all sources of ore were equal and not all swordsmiths knew how to quench harden and temper. As a matter of fact, you can run into some lively discussions on these boards as to when these practices were widely used. The old guilds held their secrets close.

 

Doug

[Mark Green]

Hi Blake & Gang,

 

I think Ric hit the nail, if your rich, your armor, and weapons were the best, no matter when you lived. Your life depended on it!

 

As for hearth steel, I have been doing a LOT of research on this for a couple years now.

Started on the path by Lee Sauder, who sent me the Evenstad papers.

The more research I do, the more convinced I have become, that the hearth purifying/carburizing process has been around for a very long time.

I now feel that a lot of the best steel we see from weapons/armor, perhaps as far back as the Roman days or beyond, come from this method.

In one or two steps, you can take slag filled bloom, and process it into near slag free steel, which is much easier to work with then steely bloom. MUCH!

Plus this process can remove many other unwanted impurities, like P.

 

Not only does it make a wonderful product, the saving in time, and Charcoal is vast.

Another reason I feel it was widely done in period. Besides all the archeological evidence.

 

Lee turned me onto this process because I had figured it out on my own. So, I very sure the makers of the day did.

 

Many smiths in the outback, may not have known this process until much later, or never. It may have even been kept as close to the tunic as possible, giving the makes that worked with this, a big advantage in quality, hence pricing.

Just as if a sword maker on the Rhine,knew how to make crucible steel. He would very likely keep this secret to the grave, or at least in house.

 

Here are some pics of the process.

http://www.bladesmithsforum.com/index.php?showtopic=25378

 

It is very likely that as time went on. Most steel was better refined, and worked, in later periods. As a whole.

 

Mark

[Blake Davidson]

Outstanding stuff, gentlemen. Thank you all for your contributions to this thread. I'll certainly start reading more about the hearth steel processes and whatever other smelting and refining processes I can. You've all given me some great stuff to think about.

[Doug Lester]

Another thing to consider is that these people didn't know on the molecular level what they were doing. Depending on what you consider later middle ages, carbon wasn't discovered for about another 400-500 years and iron was just this hard and tough metal that you could extract from some ores. Steel was considered the purest form of iron. There was no idea that it was being alloyed with anything from the fires in the forges. Judging the steel by what would be it's carbon content was hit and miss. There are examples of swords that had a low carbon edge welded to a higher carbon core so there were plenty of misses along with the hits. You also could have had steel right in that "Goldie Locks" zone were it had enough carbon to harden but would not be too brittle if not tempered and some lower carbon blades that were just work hardened. My feeling is that there was a great difference between the state of the art sword and the run-of-the-mill weapon as Ric implied.

 

Doug

[Jeroen Zuiderwijk]

When discussing the development of iron/steel in weapons, knives etc., I find that it's always looked at far to simplified, looking just at the knowledge/skill of the smiths or smelters. It's often assumed that earlier smiths didn't know what they were doing as opposed to later. You have to keep in mind that high quality steel was produced from the iron age onwards, and I'm pretty sure it was well known how to make and use it.

 

Hardenable steel has always been, and still is a minor fraction of the iron/steel produced. The simple reason for that is that soft iron is much easier to work, cheaper to produce and very suitable for most applications except for hardened edges etc. The one thing that has changed through time is developing more efficient ways to produce more iron and steel for the same amount of man hours. For example water powered bellows and powerhammers in the late medieval period allowed an increase in iron production using the same amount of effort. When there is more material, there is more steel too even if the %age of the production is still the same. That means it's easier to come by hardenable steel, as there is simply more in circulation, making it easier for smiths to gain access. Another benefit of having more iron/steel available, is that the high quality steel becomes cheaper, and therefore more accessible by people with lower incomes. Another thing that changes with greater availability of iron/steel is that there is more material to work with, thus smiths gain more experience in a shorter time, get more specialized. Rather then forging/finishing a large range of stuff, to just forging out blades which someone else finishes. The latter enables a much more efficient and consistent production of the same product. This also results again in the lowering of prices, making high end products cheaper.

 

With regards to the shift from patternwelding to monosteel, this is also a complex issue. One thing is, patternwelded sword can be just as good as monosteel once, depending on the selection of the steels used in the pattern. So the change isn't necessarily because of a higher quality. The patternwelding is however much more laborous. If you have to do a lot of folding and welding work because the iron/steel requires it to make a good steel anyway (f.e. recycling old scrap, or when receiving low processed bloom iron/steel), then the difference in time spend isn't that different between a patternwelded and a blade just folded and welded many times. When you get a steel that is already very clean and ready to be forged into a blade straight away, it is much cheaper and faster to not patternweld. So that may be a reason why patternwelding went out of favour when steel production increased, and high quality refined steel (and in particular crucible steel) became more and more available.

 

This still is a very simplified look at the matter. You really need to look at the developement of industry and society as a whole to understand these changes much better. Otherwise it's like trying to understand why bicycles underwent such a revolution in the late 19th century due to increase in knowledge of the bicycle factories, while not paying attention to the driving force of the entire industrial revolution, and how that affected every aspect of daily life, with bicycles just being one minor product that just happened to find the right breading ground allowing many innovations. I'm certain that the development of swords and other blades were for the most part a result of much larger developments that happened outside of the forges and metalworking industries at the time. F.e. improvements in efficiency in agriculture meant that more and more people were available to do other work too, such as ironworking, which boosts the industry as well. New larger cargo ships allowed much more bulk to be transported, which means (good quality) raw material also became much easier to obtain. So there's a lot more to it then just the skill of the bladesmith and smelter that make the sword.

 

N.b. also worth noting is that knives in the late medieval period were almost never made fully of steel. Most were a combination of iron with steel edges, and a lot still just pure iron (Ref. Knives and Scabbards, by J. Cowgill a.o.). I don't have much data myself on swords though.

[Blake Davidson]

Jeroen, thank you for the info. I want to make sure I'm understanding the basics of what you're saying. Higher quality steel was present from the iron age and it was known how to make it. However, broader cultural and technological shifts allowed for greater quantities to be available over time. So overall, when discussing historical iron production, an awareness of its larger context should be maintained. Am I understanding this correctly?

If any other members have words of wisdom, I would welcome them. Whatever knowledge you have on the subject is very much appreciated. This will all help me, and anyone else curious about the subject, to understand everything better and to have better starting points to reference for research. I could even apply a lot of this to bladesmithing when I can finally start and have worked at it for a few years.

[Jeroen Zuiderwijk]

Exactly. Figuring out what change made the biggest influence is the tricky part. It can be something you might not have considered relevant to bladesmithing,

[J.Arthur Loose]

If one were to survey blades made today, from factory to handmade, one would see an incredible variety of skill level and apparent understanding of the material despite the vast amounts of free information. I think it is likely that "what people knew" 1000 years ago was just as varied, so it's hard to say "Oh, they didn't know about carbon," or that across the board, folks 400 years later collectively knew more about ironworking- industrial level production and less time for material decomposition has just left us with more of an acheological record. Even here in modern (post) industrial America, as late as the early 90's, making blades by hand was fraught with general misunderstandings, and only a select few folks had solid technical knowledge.

[Doug Lester]

Actually, it's easy to say t that they didn't know about carbon 1000 years ago. Carbon wasn't discovered until the mid 18th century. Yes they knew to prepare ores in a certain way and that ores from some sources made better steel than others with no idea why. They also knew the process of extracting iron from the ore in one furnace and refining it in another. Everything was just cookbooked. Many of the records from that time referred to steel as the most refined form of iron and not an alloy so they were clueless about the carbon content of the steel.

 

Doug

[Alan Longmire]

May I commend to your attention "The metallography of early iron edged weapons" by Tylecote and Gilmour, On Divers Arts by Theophilus, Knives and Scabbards by Cowgill, De Neergard, and Griffiths, and the latest link I posted in Bloomers and Buttons, http://research.english-heritage.org.uk/report/?5274 in all of which we learn that while they may not have known that carbon was the culprit, they knew very well indeed how to tell if they had steel, iron, or high-phosphorus iron in addition to where to use it on a blade for best effect, including hardening and tempering.

 

Those four sources have examples spanning the timeframes of ca. 100 BC to the 16th century AD in which steel was used properly.

[Doug Lester]

Thanks for the link, Alan. You know as well as anyone how difficult, as well as how expensive, obtaining some of these out of print papers can be. Plan to download and read tomorrow.

 

Doug

[Blake Davidson]

I echo Doug's sentiments. Thank you very much for the links (and the recommendations for other works). I'm gonna have a library of all this stuff in no time.

 

I'm extremely thankful for all the information you fine folks have shared already. I hope this thread will continue to spark some interesting discussions or contributions. It is definitely helping me find out more about one of the fields I'm so interested in.

[Alan Longmire]

Of the works I mentioned, the only one that's out of print and thus hard to find is Tylecote and Gilmour (full citation, The Metallography of Early Ferrous Edge Tools and Edged Weapons, BAR British Research Series 155. R.F. Tylecote and B.J.J. Gilmour, 1986) That's too bad, because it is the one of greatest interest to us. Where else can you find etched cross-sections of swords, axes, knives, and spears from the late Celtic through the Viking period in England that clearly show the construction and composition of pattern-welded and built-up blades, including carbon and phosphorus content, hardness, and state of grain, i.e. whether it's been hardened or not. Bainite in a Viking sword? Yup...

 

I got a copy through inter-library loan and made a photocopy for personal use. If your local library can't locate it for you, find a college student and ask them to check their university library. Universities can get almost anything under the sun for you IF you have library privileges, so you may have to buy a lot of beer and pizza for some lucky student.

 

A great many of these things are not difficult to get unless you want to own a hardbound copy. Interlibrary loan can provide you with amazing stuff!

 

The download link above and the Knives and Scabbards book have a bit of that sort of thing, but not to the same degree of detail.

[peter johnsson]

Great posts.

One thing I´d like to nit pick is about Tylecote and Gilmour. I have a photocopy of it for personal use and find it an invaluable resource. However, it must be pointed out that it covers British/Anglosaxon material that may or may not reflect what was the norm in regards of continental or contemporary norse material.

One thing that is fascinating is that the edges of seaxes show a larger amount of steel and generally has a better standard of heat treat that what is the case with contemporary pattern welded double edged swords. This *may* tell us something about intended use and who used these weapons.

We should perhaps be careful in applying these find to what can be assumed in regards of the same weapons in continental Europe and in the Scandinavian countries.

[Richard Furrer]

I spoke to the BAR folk and it appears a new printing with more information is coming from Brian Gilmour.

So,

Tylecote and Gilmour (full citation, The Metallography of Early Ferrous Edge Tools and Edged Weapons, BAR British Research Series 155. R.F. Tylecote and B.J.J. Gilmour, 1986)

will be released again over the next few years.

 

Much of these chem/micrograph studies depend upon items to test....some are in very poor shape and thus allowed to be tested and others are in very good shape and are not allowed to be tested.

 

As Peter stated...sample bodies are limited for some regions and non-existant in others.

 

In the end what we can state for sure is that "THIS blade is X"...it may be the ONLY X there is. Generalities are what we do with a larger sample body and I wish that we had more museums giving up blades for testing....they have thousands of blades that will never see the light of day and one or two from each region and period would settle some issues and lead to a greater understanding...not to mention fill several volumes of text.

 

I know Dr. Alan Williams is interested in chopping up more blades as are others. What stands in the way is the attitude that such testing damages rather than enlightens.

 

Ric

[Alan Longmire]

I agree fully, both Peter and Ric. Having some museum training myself I understand both sides of the argument. I guess we're all really hoping someone comes up with a non-destructive way to get the same information, although I don't see that being possible. XRF, X-radiography, and neutron beam analysis can give us chemical composition and construction hints, but not the level of detail we need to fully understand the microstructures. And I do not know of any ways to test hardness that doesn't leave a mark.

 

We need to get more museum folk interested in bladesmithing so they'll be more amenable to sampling...

[Richard Furrer]

I fancy the "Warren Buffet" or "J. Paul Getty" Materials Museum Lab.......dedicated to understanding Mans's interaction with stuff.

A sort of "How its made" ancient and medieval edition.

 

Ric

[Jan Ysselstein]

Mark,

 

Agricola describes a hearth type furnace in "DE RE Metalica"...very much like the one you are experimenting with. Most of my blooms are 1/2 low carbon steel with a cast iron bottom..a very difficult combination to forge. The working temp of half the bloom will melt the other half..the working temperature must be high, due to the slag being high in Titanium.

I will test the "process" he describes*, using some of these blooms in a short furnace. I am hoping the cast will fall away and I can pull the hot remaining part of the bloom away before it picks up more carbon and sinks in the furnace...I will take the cast, as cast, or..... let the material lose carbon by air or slag. I will post some pics of the blooms before and after the process.

I do not see why under some circumstances this process would not produce a cake of wootz. Salem Steel is basically what I will be attempting..only the cast iron will be bloom fragments not bits and pieces. I will post a link to this process (Salem Steel) when I find it again.

As the bloom making process is becoming more and more familiar , the overall "expenditure" of time, energy and materials is having to be addressed ( by me), as it was in earlier periods. Ore handling , furnace building, charcoal purchasing, transport, storage and processing, smelting time, bloom processing and so on.

 

Ric,

" All Wootz is crucible steel" is surely true if the term "crucible" includes a hole in the ground under a fire and likely to be true if the term "crucible" is a ceramic vessel.

Jan

 

Edit:

 

Here is the description of Salem Steel making I will open a thread on it and Agricola's description under another single topic.

http://books.google.com/books?id=P20ZAQAAIAAJ&pg=PA451&dq=steel+making+process+salem&hl=en&sa=X&ei=OH0UUcCHJaOgiQLao4HQBA&sqi=2&ved=0CDUQ6AEwAA#v=onepage&q=steel%20making%20process%20salem&f=false

 

Jan

Edited September 8, 2013 by Jan Ysselstein

[Richard Furrer]

 

Jan,

 

Salem, India:

I would wager the decarb is a mix between the air entering and the unrefined magnetite with the silicate quartz. Such is the same in puddled iron manufacturing in Europe and the US. I do not think it will be as solid a lump as you expect due to variation in heat and exposure to the flame/slag/ironoxide.

Iron-oxide was thrown liberally into the cast iron pool along with some silicates and mixed with a rod till the carbon levels reduced and formed into a ball of iron/low carb steel. Then it was squeezed and processed into bars or plate.

 

As noted in the writeup you sited...wootz was made in a neighboring city via crucibles....no mention of wootz was in the Salem reference. I believe by stating that no wootz made in crucibles is a reference to no wootz at all and not wootz via an open hearth method......only irons and steels.

 

I see little difference between the Salem description and other finery methods in Germany....indeed it reads very similar chemically to puddled iron, though with less stirring.

 

Ric

Edited September 9, 2013 by Richard Furrer

[Jan Ysselstein]

Ric,

Let's see what happens..I have done this process ( an analog that is ) and driven it to a very soft iron (not fibrous but very solid and it had a huge grain size ). These samples should be around somewhere both the forged iron and the as processed ingot. I see comparing this process to some fineries but the low silicon content makes a comparison to puddling a poor fit. I was pointing out, the hearth concept has been around for a long time both as a process where air is used to take up most of the carbon and one where a reducing slag does the work.

 

I happened to have a lot of ingredient for both these processes and the timing is right to deplete them with some interesting play.

 

Jan

Edited September 9, 2013 by Jan Ysselstein

[Richard Furrer]

By all means Jan as experimentation is the core of such work.

I mean not to discourage anyone...not that YOU can be stopped by mere words.

 

Maybe doing the a few times and then make one a half run to see what is happening during the process rather than after it completes. I have learned far more from failures or partial success than good runs.

 

Ric