Thread: Viking sword documentary

Here is a 2-3 minute bit from a CNN piece showing the Ulfbehrt replica swords being made. There is some dramatic footage of the steel being worked.
Great Big Story

Originally Posted by Leatherstockiings

Here is a 2-3 minute bit from a CNN piece showing the Ulfbehrt replica swords being made. There is some dramatic footage of the steel being worked.
Great Big Story

Why do they sully the famous wootz steel name with movies' fantasies, and why does this great blacksmith encourage the comparison?
Also, this kind of sword is a piece that was shaped in northern Europe but the only difference between that and the failed reproductions is... the steel. That steel came from India (old big India and areas around there) and traveled north by the Volga trade route. So... the only special thing about that "Viking sword" is it's steel that is... Asian steel. That video also has a few inaccuracies; people from the area that steel was produced did make their own swords, so by definition there are older examples of legendary swords from the same material, made before this type of "Viking" sword. The technique of forging it which is also very different from classic sword forging i.e. lower temperature forging definitely traveled with the pieces of wootz, again from the people that made it and perfected the art of forging. So, compared to the plethora of very old, wootz made swords, these few pieces are special but not overly so.
I've seen the documentary plenty of times, I think everyone here refers to this one

https://www.youtube.com/watch?v=4PSZkb4OeUE

As a blacksmith, and familiar with several friends who have helped participate in these shows, the producers are selling the sizzle not the steak. I hope this word image makes sense. When filming is complete, the producers and editors assume control and often the material changes before it makes it to the public. Other experts/historians will add their opinions and knowledge to the mix.

Sweden has always had the best supply of accessible native iron ores. Not always are the ores of south Asia the ones that are used for famous steels. The particular group in northern Europe who had some successes with the Ulfbert style or type of blades, were the Franks. For about 200 years, one or two Frankish monasteries produced some of the cleanest steels ever made using what modern industry would consider primitive techniques. Even the peoples of mid-Asia were known to have sought out these steels for their swords, in preference to wootz. Good materials and good art have always traded around the world. The Vikings were famous for their travels and their mercenary work in other places besides Europe would have contributed to this type of trade.

But, history is written by conquerors and booksmiths, somewhat removed from the practical business of making the craft work to produce objects like a sword. I wish there were less gaps in the information. It's a fascinating story even without the marketing.

Few related links in the ancient swords that were discovered from Tavast, Finland. Dated in the days of the second northern crusade.

here,
here and here

Originally Posted by Mike Blue

As a blacksmith, and familiar with several friends who have helped participate in these shows, the producers are selling the sizzle not the steak. I hope this word image makes sense. When filming is complete, the producers and editors assume control and often the material changes before it makes it to the public. Other experts/historians will add their opinions and knowledge to the mix.

Sweden has always had the best supply of accessible native iron ores. Not always are the ores of south Asia the ones that are used for famous steels. The particular group in northern Europe who had some successes with the Ulfbert style or type of blades, were the Franks. For about 200 years, one or two Frankish monasteries produced some of the cleanest steels ever made using what modern industry would consider primitive techniques. Even the peoples of mid-Asia were known to have sought out these steels for their swords, in preference to wootz. Good materials and good art have always traded around the world. The Vikings were famous for their travels and their mercenary work in other places besides Europe would have contributed to this type of trade.

But, history is written by conquerors and booksmiths, somewhat removed from the practical business of making the craft work to produce objects like a sword. I wish there were less gaps in the information. It's a fascinating story even without the marketing.

You are right about editors, producers and everybody else who interferes with what we actually know about the subject. You are right about Sweden and iron ore there as well, I have read about places where if you go, collect some soil, mix it with charcoal and heat it up for some hours, you end up with actual iron alloy.
As for the Frankish steel swords, there is a catch. Indeed, they did produce a far better quality steel than the average of its time, but like every single European sword of the time, the hardening was awful. Pretty much every single sword that has been HR/Brinell/Vickers tested has far from uniform hardness, with the edge in most places not being hardened, and the majority of them being very soft.
https://myarmoury.com/feature_bladehardness.html
That's the first result I found on a quick search.
The highest quality high carbon (not above 1%) steel sword that is not hardened is only slightly better than a so so one of it's time for the only reason that, the chance of it braking is smaller.
Returning back to the wootz, that's steel with about 1.5% C that also contains a lot of carbide formers. A sword made out of this material will be a nightmare to forge, especially by hand, and again, with the lower temperature that is supposed to be forged (it brakes easily when it's yellow hot), annealing it doesn't really make things easier for forging/shaping/grinding, but when finished, its hardness will be well above that of any other sword of its time, if nothing else because of its composition. It's not just the steel, but the hardness that accompanies that specific steel with its ultra high carbon content along with "stray" carbide formers and dendritic structures that made it special for its time.
As for the people in Asia (India/Indochina/Persia) who preferred the European steel, that's a relatively recent case and it happened after the industrial revolution. And at the same time, the Europeans wanted wootz steel swords or generally swords from that area.
The people in Asia wanted European steel swords because of the purity of "our" steels, again after industrial revolution, and the people in Europe wanted Asian swords because they were "really sharp" (although once upon a time swords were really sharp, the last 300 years or so sharpness on swords kind of fell out of favor in Europe, partly because all swords were offered blunt to the soldiers to reduce accidents, until some war started and then the guys that sharpened them did a half bottomed job, and there are more than a few cases where this backfired, like the British Empire in Sudan or again British empire in some Crimea battles)
One more example on this is from a few centuries ago with the Japanese clay tempered swords. From various tests comparing them with western swords, the hardness of the edge made them prone to chipping so people thought that their steel was inferior to the western one, something that is not really true.

By the way, I'm interested in a Japanese sword made out of shirogami (I don't mind which one of the three grades but clay tempered). Anyone interesting to make one?

I have a number of comments to make and not enough time right now. A considered response will follow.

I have a "Viking Sword" make by Arms & Armour that I have had about 10 years or so Very nice sword, If you look close you can see the hammer marks were they concaved the center of the blade. It a nice sword and well balanced I asked for a 1/2 inch longer handle which I have discovered was a mistake, been thinking about sending it back and getting them to make it the proper length. Just thought I would throw this in here.

Originally Posted by Vasilis

You are right about editors, producers and everybody else who interferes with what we actually know about the subject. You are right about Sweden and iron ore there as well, I have read about places where if you go, collect some soil, mix it with charcoal and heat it up for some hours, you end up with actual iron alloy.

Smelting steel is a little more complicated than that. It is an entirely different subject to study even while the result of the work is the subject of discussion.

I propose my comments to focus the discussion and not allow a wandering collection of arguments that appear connected, but in reality are distractions and do not logically support each other.

As for the Frankish steel swords, there is a catch. Indeed, they did produce a far better quality steel than the average of its time, but like every single European sword of the time, the hardening was awful. Pretty much every single sword that has been HR/Brinell/Vickers tested has far from uniform hardness, with the edge in most places not being hardened, and the majority of them being very soft.

"every single European sword" is a collection of a large number of blades. No one article discusses them "all". There simply isn't enough resource or access to the entire collection to say this. Each article, even the C. Johnson piece only discusses a representative sample. I know Craig very well and would defer to him nearly every time, especially in this area, as he supports several of the items I have brought to it. It makes me very glad to see him putting his work into print so to speak.

It is true that hardness is variable amongst all these sample blades. The metallurgists and archeologists all have their opinions about why. The martial skills people contribute their opinions from the working tool perspective. Craig suggests several reasons that do not appear in your discussion. Blade construction chemistry is one reason, but he also mentions that the smiths had different incentives to produce blades in the manner they did that are unrelated to the values that modern smiths and customers have. This is a critical observation. We apply our modern mythology to these "great" swords/tools and are disappointed when we find they are relatively ordinary compared to what can be produced.

Still, not "every" blade tested was disappointing, nor uniformly soft. What may be more interesting is that the average values, the most common number of swords are in the middle of the hardness range and the middle of the carbon content range. Old Japanese katana are researched thoroughly and routinely found to be between 0.60-0.70% carbon. This despite the fact that their steel production, for it's day, produced tamahagane carbon contents in the 1.4-1.6% range. Some part of the smithing technique reduces that carbon content. It seems the Europeans were producing blades with similar chemistries. The Japanese use this carbon content as a means to develop the hamon. This portion of the art quality of their blades is highly valued even though the resulting carbon content is sneered at by so many who believe you must have a high carbon content in your blades. It ain't necessarily so, if a wider view is adopted.

The highest quality high carbon (not above 1%) steel sword that is not hardened is only slightly better than a so so one of it's time for the only reason that, the chance of it braking is smaller.

But none of Craig's sample (I hope you looked at more than one sample.), the one we have to discuss, does not have carbon contents approaching 1%. But you need to specify why it's better, or the exact quality of the blade that somehow makes that different. An unhardened bar of 1% steel might or might not be tougher (avoiding fracture) than a lesser steel. A hardened high carbon steel could be much more likely to fracture than otherwise. But none of the conditions of heat treatment or other aspects are raised here and it's difficult to respond without them.

There are other collections of representative samples to which authors had access. No one to date has proposed putting all this data into one file for comparision purposes. Statistically a larger sample size is preferred.

From a combat perspective, I suspect the customers had a large portion of influence over blade construction. Sure they wanted a beautiful pattern welded, name inset ala Ulfbert, but they wanted a blade that did not break during a fight. A broken sword is a distinct disadvantage fighting against another fellow armed with a bent but still intact weapon. More soldiers on the field were likely armed with a wider variety of spears for this very reason. Again this depends on fighting techniques too, martial styles. Some groups favored axes and were feared for it. There are Chinese discussions of old swords that for all modern purposes were merely iron clubs used by the good fighters, and the death act was accomplished by squires or follow-on foot soldiers.

Perhaps fighting technique is more important than the weapon itself.

Returning back to the wootz, that's steel with about 1.5% C that also contains a lot of carbide formers. A sword made out of this material will be a nightmare to forge, especially by hand, and again, with the lower temperature that is supposed to be forged (it brakes easily when it's yellow hot), annealing it doesn't really make things easier for forging/shaping/grinding, but when finished, its hardness will be well above that of any other sword of its time, if nothing else because of its composition. It's not just the steel, but the hardness that accompanies that specific steel with its ultra high carbon content along with "stray" carbide formers and dendritic structures that made it special for its time.

Wootz forges like butter, compared to modern high carbon tool steels. Most of the low alloy, ultra high carbon steels do. Visit a smith's shop who works this material and discover this for yourself. Ric teaches classes in both smelting and working the material. It would be well worth your visit.

Any blade at Rc 60 (any tested value) will be the same hardness regardless of blade chemistry. There may be other characteristics like stain resistance or toughness that are affected by chemistry. Hardness is merely one value to be studied. Wootz is not inherently harder because it's wootz. It has to have the smith heat treat it. Depending on their methods or understanding that could turn out to be legendary or ordinary. The material itself is not magical.

As for the people in Asia (India/Indochina/Persia) who preferred the European steel, that's a relatively recent case and it happened after the industrial revolution. And at the same time, the Europeans wanted wootz steel swords or generally swords from that area.
The people in Asia wanted European steel swords because of the purity of "our" steels, again after industrial revolution, and the people in Europe wanted Asian swords because they were "really sharp" (although once upon a time swords were really sharp, the last 300 years or so sharpness on swords kind of fell out of favor in Europe, partly because all swords were offered blunt to the soldiers to reduce accidents, until some war started and then the guys that sharpened them did a half bottomed job, and there are more than a few cases where this backfired, like the British Empire in Sudan or again British empire in some Crimea battles)

There are plenty of afficionados of this sort of discussion all over the net. The specialize in their era and I have little hope of summarizing all the periods involved. My personal inspection of multiple horse-mounted blades from different cultures and different era, generally supports the lack of sharp favored over sharp. If you consider an older culture where armor was likely, the sharp edge would not survive contact with materials designed to resist it, or it would stick in the material and injure the arm of the cutter. As a blunt club, it could break bones even through the armor, unhorse the rider and leave him hors de combat for the fellows with the spears. A more thorough discussion of the martial skills involved would help but is a distraction from the OP.

One more example on this is from a few centuries ago with the Japanese clay tempered swords. From various tests comparing them with western swords, the hardness of the edge made them prone to chipping so people thought that their steel was inferior to the western one, something that is not really true.

There are better studies available from WWII. The Spirit of the Sword: Iaido, Kendo, and Test Cutting with the Japanese Sword
Nakamura Taisaburo Taisaburo contends that the sword was not the problem but the techniques used in cutting that were at fault.

As long as we can add to the understanding and not split the discussion, I'm in favor of whatever contribution occurs. I hope this helps.

Thank you Mike Blue, still, I do have a couple of points to make about your answer.
First of all, about Scandinavian soil that becomes iron, you are absolutely right, and of course it's more complicated than that. I was merely referring to the fact that there are places where seemingly ordinary soil is actually an iron ore source, although a poor one, and its reduction, or oxidation (of FeS2) and then reduction would yeld some iron. Far from the stuff needed to make quality iron/steel, especially with the traditional methods, let alone edged instruments.

For my claim about "every single European sword" that is less than not only optimally but even decently forged and tempered even with higher quality steel, I still believe it to be right, no matter the number of samples.
It might be because of the temperature of the forge that is not uniform resulting on uneven temper, it might be because of the oxidation/decarburisation of the steel, heated when coming to contact with the air while forging/folding/heating, which in turn will reduce the carbon content and a piece with 0.5%C will have different hardness than a 0.7%C when tempered the same way... I think these are the most common reasons for uneven hardness and carbon content on the places of the blade that should be similar i.e. edge, spine or even tang, for homogeneous steel, using the folding method.
One more reason for uneven hardness could be the failure rate; the more you try to increase the hardness, the more swords will end up broken, and, the harder the sword, the easier it brakes; better for a sword to bend in the battle than brake. Even if you had Excalibur (without the beam of light) and an Albion, similar Oakeshott type, the Albion would perform much better. A blacksmith of that time didn't have the knowledge, the quality raw materials be that steel or carbon, or the equipment to produce something that would not be considered better than "so so" today. Still, they absolutely did their job, so, in the end these "failed" swords did performed their job just fine (usually as secondary weapons but that's for another discussion).
For the Japanese swords now, the carbon content from samples I have seen range from 0.45 to 0.9%, I think I have also seen one at 1%.
Tamahagane has several grades. The boulder that comes out of the "tatara" has very high carbon on the outer "layer" where it came in contact with a lot of carbon, and in the center where the ore didn't come in contact with enough it's mild steel. Between them there are varying degrees of carbon content decreasing as you reach the center. That outer part with carbon content above 1%, it could even be 1.5% doesn't go for swords but for plane blades, kamisori, chisels and knives (and of course, it loses some of it's carbon while forging, even intentionally by the blacksmith). The mild steel was used for the softer part of edged instruments to make sharpening easier, for decorative objects because it's easier to forge/shape and for swords on the center of the blade on ridiculously complicated constructions with 6 or even more different types of steel on the blade,


Hamon is not just a layer of hardened steel sandwiched between layers of softer one, it's a result of tempering, but being a blacksmith I'm sure you know it.

It is to my understanding that Europeans were using similar techniques as you mentioned, to make steel, to a varying degree of success.
As for the wider view of the people who think that a sword must be made with high carbon steel, unless there is nitrogen in it, I agree with them. High carbon steel holds an edge better than medium/low carbon steel or bronze. A combination of high carbon steel edge and lower carbon steel other than edge parts of the sword are not the optimal idea because the chance of something going wrong in the welding and folding process is higher. And, there is a chance for the sword to warp if handled incorrectly, so, I would prefer high carbon steel.

"But none of Craig's sample (I hope you looked at more than one sample.), the one we have to discuss, does not have carbon contents approaching 1%. But you need to specify why it's better, or the exact quality of the blade that somehow makes that different. An unhardened bar of 1% steel might or might not be tougher (avoiding fracture) than a lesser steel. A hardened high carbon steel could be much more likely to fracture than otherwise. But none of the conditions of heat treatment or other aspects are raised here and it's difficult to respond without them."
Yes, you are absolutely right, and that's what I was talking about. The highest quality of today's steel, unhardened, is slightly better than one from say 500 to 1500, for the simple reason that, the fewer to almost zero inclusions today's steel make it less likely to brake compared to that time's steel that had inclusions and the folding process could have gone wrong. For Carbon content above 1%, it becomes somewhat dangerous, but not really.

Again, I agree that customers, especially rich ones did influence the construction, even if that made the sword less useful or practical (Cinquedea) and once again, I agree 100% that the technique and knowledge on how to wield it is more important than the sword.

As for wootz, I don't want to be misunderstood; I don't consider it to be some miracle steel, but I do think that from the age it started being used and for many centuries later, it was far better than any other steel, for edged instruments. As for forging it, the fact that is forged like "butter", that's the first time I hear about it. From people who have taken classes, I know a gentleman who spend two weeks, many hours per day, heating and mostly hitting a small piece to make a small knife. Forged at red hot temperature, not brighter because then it becomes brittle like glass like all ultra high carbon low ally steels, and all that under supervision from the blacksmith that made the ingots. I do intend to visit a blacksmith who works with the material, but for now I can't afford it.
Finally, needless to say, I'm well aware of what HRC means, theoretically and practically, but only at sharpening/honing, as well as elements that change the behavior of steel. zknives has an interesting section on it. The hardness of wootz knives/swords that I consider higher than that of most European steel swords is because of the difficulty forging it, and air hardening; it contains so much carbon, water quenching or any type of quenching at that time would not really work.

Originally Posted by Mike Blue

Smelting steel is a little more complicated than that. It is an entirely different subject to study even while the result of the work is the subject of discussion.

I propose my comments to focus the discussion and not allow a wandering collection of arguments that appear connected, but in reality are distractions and do not logically support each other.



"every single European sword" is a collection of a large number of blades. No one article discusses them "all". There simply isn't enough resource or access to the entire collection to say this. Each article, even the C. Johnson piece only discusses a representative sample. I know Craig very well and would defer to him nearly every time, especially in this area, as he supports several of the items I have brought to it. It makes me very glad to see him putting his work into print so to speak.

It is true that hardness is variable amongst all these sample blades. The metallurgists and archeologists all have their opinions about why. The martial skills people contribute their opinions from the working tool perspective. Craig suggests several reasons that do not appear in your discussion. Blade construction chemistry is one reason, but he also mentions that the smiths had different incentives to produce blades in the manner they did that are unrelated to the values that modern smiths and customers have. This is a critical observation. We apply our modern mythology to these "great" swords/tools and are disappointed when we find they are relatively ordinary compared to what can be produced.

Still, not "every" blade tested was disappointing, nor uniformly soft. What may be more interesting is that the average values, the most common number of swords are in the middle of the hardness range and the middle of the carbon content range. Old Japanese katana are researched thoroughly and routinely found to be between 0.60-0.70% carbon. This despite the fact that their steel production, for it's day, produced tamahagane carbon contents in the 1.4-1.6% range. Some part of the smithing technique reduces that carbon content. It seems the Europeans were producing blades with similar chemistries. The Japanese use this carbon content as a means to develop the hamon. This portion of the art quality of their blades is highly valued even though the resulting carbon content is sneered at by so many who believe you must have a high carbon content in your blades. It ain't necessarily so, if a wider view is adopted.



But none of Craig's sample (I hope you looked at more than one sample.), the one we have to discuss, does not have carbon contents approaching 1%. But you need to specify why it's better, or the exact quality of the blade that somehow makes that different. An unhardened bar of 1% steel might or might not be tougher (avoiding fracture) than a lesser steel. A hardened high carbon steel could be much more likely to fracture than otherwise. But none of the conditions of heat treatment or other aspects are raised here and it's difficult to respond without them.

There are other collections of representative samples to which authors had access. No one to date has proposed putting all this data into one file for comparision purposes. Statistically a larger sample size is preferred.

From a combat perspective, I suspect the customers had a large portion of influence over blade construction. Sure they wanted a beautiful pattern welded, name inset ala Ulfbert, but they wanted a blade that did not break during a fight. A broken sword is a distinct disadvantage fighting against another fellow armed with a bent but still intact weapon. More soldiers on the field were likely armed with a wider variety of spears for this very reason. Again this depends on fighting techniques too, martial styles. Some groups favored axes and were feared for it. There are Chinese discussions of old swords that for all modern purposes were merely iron clubs used by the good fighters, and the death act was accomplished by squires or follow-on foot soldiers.

Perhaps fighting technique is more important than the weapon itself.



Wootz forges like butter, compared to modern high carbon tool steels. Most of the low alloy, ultra high carbon steels do. Visit a smith's shop who works this material and discover this for yourself. Ric teaches classes in both smelting and working the material. It would be well worth your visit.

Any blade at Rc 60 (any tested value) will be the same hardness regardless of blade chemistry. There may be other characteristics like stain resistance or toughness that are affected by chemistry. Hardness is merely one value to be studied. Wootz is not inherently harder because it's wootz. It has to have the smith heat treat it. Depending on their methods or understanding that could turn out to be legendary or ordinary. The material itself is not magical.



There are plenty of afficionados of this sort of discussion all over the net. The specialize in their era and I have little hope of summarizing all the periods involved. My personal inspection of multiple horse-mounted blades from different cultures and different era, generally supports the lack of sharp favored over sharp. If you consider an older culture where armor was likely, the sharp edge would not survive contact with materials designed to resist it, or it would stick in the material and injure the arm of the cutter. As a blunt club, it could break bones even through the armor, unhorse the rider and leave him hors de combat for the fellows with the spears. A more thorough discussion of the martial skills involved would help but is a distraction from the OP.



There are better studies available from WWII. The Spirit of the Sword: Iaido, Kendo, and Test Cutting with the Japanese Sword
Nakamura Taisaburo Taisaburo contends that the sword was not the problem but the techniques used in cutting that were at fault.

As long as we can add to the understanding and not split the discussion, I'm in favor of whatever contribution occurs. I hope this helps.

Originally Posted by Vasilis

...First of all, about Scandinavian soil that becomes iron, you are absolutely right, and of course it's more complicated than that. I was merely referring to the fact that there are places where seemingly ordinary soil is actually an iron ore source, although a poor one, and its reduction, or oxidation (of FeS2) and then reduction would yeld some iron. Far from the stuff needed to make quality iron/steel, especially with the traditional methods, let alone edged instruments.

Iron and Nickel are the two heaviest elements produced by our sun. These elements fall to earth via the solar wind. By mass it is the most common element on earth. I would expect to find it everywhere to some degree. Concentrated iron ores are more practical for mining. During my study of smelting techniques, I discovered simple Viking methods that would have both served as production of trade goods (iron or steels) and a source of heat for the farms. Bog ores are relatively concentrated forms of iron that make further concentration of the iron more efficient. Deriving iron from soils would be impractical for peoples who don't want to waste time or resources.

...A blacksmith of that time didn't have the knowledge, the quality raw materials be that steel or carbon, or the equipment to produce something that would not be considered better than "so so" today.

My most general comment is that human beings are keen observers and intelligent regardless of the Era in which they live or the crafts they pursued. What we assume about their knowledge and ability is sometimes a dangerous arrogance.

For the Japanese swords now, the carbon content from samples I have seen range from 0.45 to 0.9%, I think I have also seen one at 1%.
Tamahagane has several grades. The boulder that comes out of the "tatara" has very high carbon on the outer "layer" where it came in contact with a lot of carbon, and in the center where the ore didn't come in contact with enough it's mild steel. Between them there are varying degrees of carbon content decreasing as you reach the center. That outer part with carbon content above 1%, it could even be 1.5% doesn't go for swords but for plane blades, kamisori, chisels and knives (and of course, it loses some of it's carbon while forging, even intentionally by the blacksmith). The mild steel was used for the softer part of edged instruments to make sharpening easier, for decorative objects because it's easier to forge/shape and for swords on the center of the blade on ridiculously complicated constructions with 6 or even more different types of steel on the blade,

I will suggest a wider range of reading. Especially about carbon migration as this process really does explain the process of making steel from iron ores. Your understanding of the carbon contents in a tamahagane/kera bloom is incorrect. The center of the bloom has a significant amount of carbon. You should read more about Japanese blade constructions. The Japanese, or any smith, would prefer not using mild steel as the edge of any edged tools.

My argument is for more samples, not using single sources. I think over a much larger number of blades you will find the average carbon values surrounding 0.6%. There is considerable controlled metallurgical research available in Japanese to support my concerns in this area. The Japanese swordsmiths, with whom I've had numerous discussions, reinforce their impression that working in carbon contents higher than 0.7% is possible but not recommended.

Hamon is not just a layer of hardened steel sandwiched between layers of softer one, it's a result of tempering, but being a blacksmith I'm sure you know it.

Yes. Technically it is better to refer to the hamon as the hardening line since it's the transition between the hardened edge and the softer structures of steel in the mid body or spine of the blade. The smith first hardens the steel, then tempers (stress reduces) the object hardened. Old ways of naming things can confuse people.

It is to my understanding that Europeans were using similar techniques as you mentioned, to make steel, to a varying degree of success.
As for the wider view of the people who think that a sword must be made with high carbon steel, unless there is nitrogen in it, I agree with them. High carbon steel holds an edge better than medium/low carbon steel or bronze. A combination of high carbon steel edge and lower carbon steel other than edge parts of the sword are not the optimal idea because the chance of something going wrong in the welding and folding process is higher. And, there is a chance for the sword to warp if handled incorrectly, so, I would prefer high carbon steel.

Yes, this was a very common method to save good steel for more blades. See the Tower of London excavations research. https://www.amazon.com/Tower-London-.../dp/0904220354 Within are some excellent discussions of the blades found there.

"But none of Craig's sample (I hope you looked at more than one sample.), the one we have to discuss, does not have carbon contents approaching 1%. But you need to specify why it's better, or the exact quality of the blade that somehow makes that different. An unhardened bar of 1% steel might or might not be tougher (avoiding fracture) than a lesser steel. A hardened high carbon steel could be much more likely to fracture than otherwise. But none of the conditions of heat treatment or other aspects are raised here and it's difficult to respond without them."

Yes, you are absolutely right, and that's what I was talking about. The highest quality of today's steel, unhardened, is slightly better than one from say 500 to 1500, for the simple reason that, the fewer to almost zero inclusions today's steel make it less likely to brake compared to that time's steel that had inclusions and the folding process could have gone wrong. For Carbon content above 1%, it becomes somewhat dangerous, but not really.

But my point was that the Franks produced clean crucible steels that did not require folding and rewelding. They, despite our belief about their abilities, were capable of producing steels cleaner than we expected. How they did it is lost to us, except for those men like Ric Furrer who pursue replication of their techniques. If you look into modern metal production, our steels have to meet certain specifications chemically. But, the ladles used are multi purpose. One time they produce tool steels by the ton, the next run they produce construction steels. There are so many contaminating minor alloys that leach from the ladle into the molten bloom that it affects our ability to heat treat tool steels despite what the steel company says when it meets specifications for the alloy. I would suggest that our era has produced more contamination in alloys than historically. We recycle everything these days and it makes its way into the big melters if it's metal.

As for wootz, I don't want to be misunderstood; I don't consider it to be some miracle steel, but I do think that from the age it started being used and for many centuries later, it was far better than any other steel, for edged instruments. As for forging it, the fact that is forged like "butter", that's the first time I hear about it. From people who have taken classes, I know a gentleman who spend two weeks, many hours per day, heating and mostly hitting a small piece to make a small knife. Forged at red hot temperature, not brighter because then it becomes brittle like glass like all ultra high carbon low ally steels, and all that under supervision from the blacksmith that made the ingots. I do intend to visit a blacksmith who works with the material, but for now I can't afford it.

It's really simple alloy metallurgically. Perhaps even modern metallurgists would consider wootz to be a "so-so" alloy given what they know now. The process you describe is one moment in the life of a wootz button. The reason for careful forging and temperature control immediately after smelting is the size of the carbides present. Temperature control is a large part of that process too. Those need to be worked to move the button into a bar ready to make a blade from. Once that bar is consolidated, the steel feels less stiff under the hammer than a modern bar of tool steel. I encourage you to visit your blacksmith friend. Having a hammer in your hand is worth far more than any discussion we can have here.

Continue to read/study. There is a lot more information out there that will refine what you know over time. Some you will learn are contradictory depending on certain conditions like time and temperature. It takes a lifetime of study to learn them all.