More questions about wootz

ariel · 14th November 2008, 04:40 AM

All wootz ingots I've seen weighed less than 1 kg. Khorasani writes that crucibles were filled with ~ 300-400 g of iron. A long Khanda blade weighs about a kg or more and a shamshir blade weighs ~ 600g. Some raw material must have been lost during blade making.
Question #1: were long blades made of several ingots or was I unlucky enough to see only small ingots?
Question #2: is there anything special about Turkish wootz?
Question #3: are there any differences in mechanical properties between different kinds of wootz: Kara Khorasan, Kara Toban, Kirk Narduban and Shams? I am not asking about esthetical appeal; purely practilal qualities.

Richard Furrer · 14th November 2008, 06:51 PM

Depending upon how much patterning or forging quite a bit of material can be lost as forging scale or filed away.

As to average sizes of ingots, well, without a very large sample body or quite a few broken crucibles from many sites of manufacture I am not sure we can answer that question.
However
One can look at various axes or large katar or pieces of armor as reference points...forging a shield or breast plate requires many heating cycles (hundreds) and there is better than 50% loss in such work. Some ingots were more than a kilo...certainly given the pyrotechnology history of the larger area large fires were present. I would go so far as to say HUGE melts had been done, but it comes down to the need and the desire to make an item from one large piece verses several small ones...at some point the benefit is lost.
When I began forge-welding by hand a two pound billet was pretty big, now I weld 22 pound billets in one go with my tools.

If a blade were made from more than one ingot then there would be a sign of this (if etched). In polished or burnished condition it would be difficult/impossible to tell. I have seen many, many swords made with two or more welds though one must be careful how this is evaluated as it may mean a repair (rejoining of a broken blade) rather than two ingots.

As to different areas and their wootz...not enough testing has been done to show a comparison. Much is shown of micro-graphs, but there again the sample body is small. I did some bending to failure of an India tulwar yielding foot pounds of force and degree of bend, but this means little unless other blades are broken in this way. I had these tests done to create a baseline for my own wootz work..but...I'm always looking for broken blades to carry out more tests.
I do not think any real database can be made unless many samples are tested and museums and collectors have little interest in this as it means little to them......what does a museum care if the swords they have on display are metallurgically sound, "properly" heat treated or keen for use?

Ric

Jeff Pringle · 17th November 2008, 07:46 AM

I just got a look at a sword made of two ingots, welded together near the middle of the blade, and there were the remains of cuts where the smith had inlaid an inscription on both sides where the seam showed – I wonder what it said? Hopefully I can get a photo of it. I have also seen more than a few swords where the wootz had been used to sandwich regular steel in the center, so they had ways of extending their ingots to sword length.

I’ve only seen a couple items referred to as ‘Turkish’ wootz, they looked like what is also called ‘sham’, or in other words, nothing special.

The terms are not uniformly well defined, I think. They are all visual descriptives, so would only imply mechanical differences accidentally, if the mechanical difference manifested also in the pattern.
Kirk Narduban is referring to a pattern manipulation and so does not have any practical difference.
Those blades I’ve seen referred to as ‘shams’ all look (to me

) to be steel of lower carbon than what we makers think of today as wootz, if that is the case then there would be a difference – Sham blades would act just like regular blades, since the steel is about the same. When al Kindi wrote about second-class blades which did not show a pattern until you threw acid on them, I think this is what he was referring to.
Kara Khorasan and Kara Toban are probably similar in mechanical properties to each other, but different than shams.

Take a look at figure 2 in this article and see if you can put a name to each of the four wootz blades…

http://www.tms.org/pubs/journals/JOM...even-9809.html

Jens Nordlunde · 17th November 2008, 01:45 PM

Wrong thread - sorry

14th November 2008, 04:40 AM	#1
ariel Member Join Date: Dec 2004 Location: Ann Arbor, MI Posts: 5,503	More questions about wootz All wootz ingots I've seen weighed less than 1 kg. Khorasani writes that crucibles were filled with ~ 300-400 g of iron. A long Khanda blade weighs about a kg or more and a shamshir blade weighs ~ 600g. Some raw material must have been lost during blade making. Question #1: were long blades made of several ingots or was I unlucky enough to see only small ingots? Question #2: is there anything special about Turkish wootz? Question #3: are there any differences in mechanical properties between different kinds of wootz: Kara Khorasan, Kara Toban, Kirk Narduban and Shams? I am not asking about esthetical appeal; purely practilal qualities. Last edited by ariel; 14th November 2008 at 05:23 AM.

14th November 2008, 06:51 PM	#2
Richard Furrer Member Join Date: Mar 2006 Location: Sturgeon Bay, Wisconsin Posts: 163	Depending upon how much patterning or forging quite a bit of material can be lost as forging scale or filed away. As to average sizes of ingots, well, without a very large sample body or quite a few broken crucibles from many sites of manufacture I am not sure we can answer that question. However One can look at various axes or large katar or pieces of armor as reference points...forging a shield or breast plate requires many heating cycles (hundreds) and there is better than 50% loss in such work. Some ingots were more than a kilo...certainly given the pyrotechnology history of the larger area large fires were present. I would go so far as to say HUGE melts had been done, but it comes down to the need and the desire to make an item from one large piece verses several small ones...at some point the benefit is lost. When I began forge-welding by hand a two pound billet was pretty big, now I weld 22 pound billets in one go with my tools. If a blade were made from more than one ingot then there would be a sign of this (if etched). In polished or burnished condition it would be difficult/impossible to tell. I have seen many, many swords made with two or more welds though one must be careful how this is evaluated as it may mean a repair (rejoining of a broken blade) rather than two ingots. As to different areas and their wootz...not enough testing has been done to show a comparison. Much is shown of micro-graphs, but there again the sample body is small. I did some bending to failure of an India tulwar yielding foot pounds of force and degree of bend, but this means little unless other blades are broken in this way. I had these tests done to create a baseline for my own wootz work..but...I'm always looking for broken blades to carry out more tests. I do not think any real database can be made unless many samples are tested and museums and collectors have little interest in this as it means little to them......what does a museum care if the swords they have on display are metallurgically sound, "properly" heat treated or keen for use? Ric

17th November 2008, 07:46 AM	#3
Jeff Pringle Member Join Date: Nov 2005 Posts: 189	I just got a look at a sword made of two ingots, welded together near the middle of the blade, and there were the remains of cuts where the smith had inlaid an inscription on both sides where the seam showed – I wonder what it said? Hopefully I can get a photo of it. I have also seen more than a few swords where the wootz had been used to sandwich regular steel in the center, so they had ways of extending their ingots to sword length. I’ve only seen a couple items referred to as ‘Turkish’ wootz, they looked like what is also called ‘sham’, or in other words, nothing special. The terms are not uniformly well defined, I think. They are all visual descriptives, so would only imply mechanical differences accidentally, if the mechanical difference manifested also in the pattern. Kirk Narduban is referring to a pattern manipulation and so does not have any practical difference. Those blades I’ve seen referred to as ‘shams’ all look (to me ) to be steel of lower carbon than what we makers think of today as wootz, if that is the case then there would be a difference – Sham blades would act just like regular blades, since the steel is about the same. When al Kindi wrote about second-class blades which did not show a pattern until you threw acid on them, I think this is what he was referring to. Kara Khorasan and Kara Toban are probably similar in mechanical properties to each other, but different than shams. Take a look at figure 2 in this article and see if you can put a name to each of the four wootz blades… http://www.tms.org/pubs/journals/JOM...even-9809.html

17th November 2008, 01:45 PM	#4
Jens Nordlunde Member Join Date: Dec 2004 Location: Europe Posts: 2,713	Wrong thread - sorry