Another wootz question

ariel · 2nd January 2009, 12:34 AM

Re-reading Figiel's book.
All high-class wootz blades seem to be "built" of 2 sections: the body is covered with intricate " whorly" design, but the edge consists of long, relatively straight lines, resembling the Sham pattern. Of course, these are not made of a different ingot, but are simply the result of a more extensive hammering.
My question: what do we know about the effect of the extent of forging on the structure of wootz? Is it possible, that the so-called "pedestrian" Sham pattern is simply the result of over-hammering?

Jeff Pringle · 2nd January 2009, 04:31 PM

It is dangerous to assume anything written on the technical aspects of wootz is correct, at least before Verhoeven & Pendray’s Scientific American article in 2000. I suspect Figiel is wrong in his reasoning - the lines show up more at the edge due to more extensive grinding there, not hammering. The same effect happens in pattern welded material. If we assume the ingots were all roughly the same size, then they would all need the same amount of hammering to be transformed from ingot to blade material.

ALEX · 2nd January 2009, 04:38 PM

An outstanding analytical question, Ariel!
You are correct - these lines are result of extensive forging, BUT they develop on edges only! If it would be just result of overhammering/multiple forging cycles we'd see these lines throughout the entire width. I think it has to do with cooling as well = the edges cool faster than the core because they are thinner, and it allows the contrast to develop more "gracefully"... granting it has been properly hammered and from a top quality wootz ingot!
I do not think sham is a result of overhammering alone, I think it's more a result of low-contrast ingot to begin with, and perhaps under-hammering:-)
Also, the presense of these lines on the edge indicate the better (and perhaps earlier made) quality of the blade to me - I often see them on better patterned, such as Kirk laddered, blades. Not sure if grinding alone can create such an effect.

ariel · 2nd January 2009, 07:41 PM

Cooling is a good one!
Not being a metalworker, I would still assume that more hammering is needed to achieve a thinner edge than a thicker body.
No matter what: the edges of the highest-quality wootz blades look like Sham.
Thus, the question remains: is Sham an "overworked" Kara Khorasan?

Jeff D · 2nd January 2009, 09:04 PM

I am of the belief that sham is quite different than kara khorasan. The edges of a khorsan blade has thin stripes in the same manner that the ladder pattern has thinner stripes. Most likely during the forging the original pearlite and cementite crystals are elongated and thinned. When the blade is 'beveled' for the edge or a ladder you see the thinner cross section of the bands. My understanding that if the blade has a lot of hammering, it breaks up these crystals to give the 'jumble of matches' appearance seen on many fine Indian pieces.
The etching of sham is also quite different than the etch of khorsan. Philip Tom has explained it to me more as a slow controlled rust. This indicates to me that it has a different chemistry.

Here are a couple of my own blades to illustrate. First picture is kara khorsan with its edge, the second is a Turkish sham kilij, and the third is a ladder rung.

All the best Jeff

ariel · 3rd January 2009, 12:01 AM

If that's the case, the ingot must have been the determining factor. Then, how did the smiths know which one will produce a Khorasan and which one a Sham? They would have to finish the blade and etch it to reveal the final result. Lower quality(Sham) would have not been discarded ( too expensive), but just sold for a lower price. The highest quality would have been signed "Assadollah". Then, where is the multitude of Sham blades from Iran? Why would ingots from the same source ( mostly India) produce Khorasan blades in Iran and Sham in Turkey? Did the Ottoman bladesmiths consciously select ingots with Sham pattern?

Jeff D · 3rd January 2009, 01:32 AM

Quote:

Originally Posted by ariel

The highest quality would have been signed "Assadollah".

Only if it was made by the family line

Quote:

Originally Posted by ariel

Then, where is the multitude of Sham blades from Iran? Why would ingots from the same source ( mostly India) produce Khorasan blades in Iran and Sham in Turkey? Did the Ottoman bladesmiths consciously select ingots with Sham pattern?

Here I don't know the answer, but, I have always assumed that the ingots came from a different source. Even if they came from the same source but a different batch, I believe the ingots had an surface appearance which could be differentiated by an experienced eye.

Jeff

kisak · 3rd January 2009, 03:12 PM

Quote:

Originally Posted by ariel

If that's the case, the ingot must have been the determining factor. Then, how did the smiths know which one will produce a Khorasan and which one a Sham?

Manouchehr's book mentions smiths determining the quality of wootz ingots by polishing (and etching?) a small part of the surface.

2nd January 2009, 12:34 AM	#1
ariel Member Join Date: Dec 2004 Location: Ann Arbor, MI Posts: 5,503	Another wootz question Re-reading Figiel's book. All high-class wootz blades seem to be "built" of 2 sections: the body is covered with intricate " whorly" design, but the edge consists of long, relatively straight lines, resembling the Sham pattern. Of course, these are not made of a different ingot, but are simply the result of a more extensive hammering. My question: what do we know about the effect of the extent of forging on the structure of wootz? Is it possible, that the so-called "pedestrian" Sham pattern is simply the result of over-hammering?

2nd January 2009, 09:04 PM	#5
Jeff D Member Join Date: Dec 2004 Location: B.C. Canada Posts: 473	I am of the belief that sham is quite different than kara khorasan. The edges of a khorsan blade has thin stripes in the same manner that the ladder pattern has thinner stripes. Most likely during the forging the original pearlite and cementite crystals are elongated and thinned. When the blade is 'beveled' for the edge or a ladder you see the thinner cross section of the bands. My understanding that if the blade has a lot of hammering, it breaks up these crystals to give the 'jumble of matches' appearance seen on many fine Indian pieces. The etching of sham is also quite different than the etch of khorsan. Philip Tom has explained it to me more as a slow controlled rust. This indicates to me that it has a different chemistry. Here are a couple of my own blades to illustrate. First picture is kara khorsan with its edge, the second is a Turkish sham kilij, and the third is a ladder rung. All the best Jeff Attached Images

2nd January 2009, 04:31 PM	#2
Jeff Pringle Member Join Date: Nov 2005 Posts: 189	It is dangerous to assume anything written on the technical aspects of wootz is correct, at least before Verhoeven & Pendray’s Scientific American article in 2000. I suspect Figiel is wrong in his reasoning - the lines show up more at the edge due to more extensive grinding there, not hammering. The same effect happens in pattern welded material. If we assume the ingots were all roughly the same size, then they would all need the same amount of hammering to be transformed from ingot to blade material.

2nd January 2009, 04:38 PM	#3
ALEX Member Join Date: Jan 2006 Posts: 936	An outstanding analytical question, Ariel! You are correct - these lines are result of extensive forging, BUT they develop on edges only! If it would be just result of overhammering/multiple forging cycles we'd see these lines throughout the entire width. I think it has to do with cooling as well = the edges cool faster than the core because they are thinner, and it allows the contrast to develop more "gracefully"... granting it has been properly hammered and from a top quality wootz ingot! I do not think sham is a result of overhammering alone, I think it's more a result of low-contrast ingot to begin with, and perhaps under-hammering:-) Also, the presense of these lines on the edge indicate the better (and perhaps earlier made) quality of the blade to me - I often see them on better patterned, such as Kirk laddered, blades. Not sure if grinding alone can create such an effect.

2nd January 2009, 07:41 PM	#4
ariel Member Join Date: Dec 2004 Location: Ann Arbor, MI Posts: 5,503	Cooling is a good one! Not being a metalworker, I would still assume that more hammering is needed to achieve a thinner edge than a thicker body. No matter what: the edges of the highest-quality wootz blades look like Sham. Thus, the question remains: is Sham an "overworked" Kara Khorasan?

3rd January 2009, 12:01 AM	#6
ariel Member Join Date: Dec 2004 Location: Ann Arbor, MI Posts: 5,503	If that's the case, the ingot must have been the determining factor. Then, how did the smiths know which one will produce a Khorasan and which one a Sham? They would have to finish the blade and etch it to reveal the final result. Lower quality(Sham) would have not been discarded ( too expensive), but just sold for a lower price. The highest quality would have been signed "Assadollah". Then, where is the multitude of Sham blades from Iran? Why would ingots from the same source ( mostly India) produce Khorasan blades in Iran and Sham in Turkey? Did the Ottoman bladesmiths consciously select ingots with Sham pattern?