Ingots

[Jens Nordlunde]

Gene, Jonathan and Jim,

Thank you for your posts. I have only seen ingots/mill balls on pictures, so I am not the right one to answer what exactly they look like, so I think Gene should ask Ann what it is. I have however seen the mill balls described like this. “If it has a spherical, or nearly so, form, have a smooth surface then it is very unlikely that it is an ingot.”

If you go to the link above and read post 37 Jeff Pringle gives some of the answer. Here is a short quote, “All steels solidify with a dendritic structure, not just wootz, so that is irrelevant but often comes up because people first hear of crystalline dendrites in steel via wootz.”

Jim, I don’t know what a test would cost, the only thing I have heard is, that it takes some hours of work, so it may be as expensive as the item in question.

Jens

[Jeff Pringle]

Since the last time this topic cropped up I found another photo of an original ingot, and a good illustration or two of the crucibles used to make them (which, of course, define the shape of the ingot ). The easy diagnostic feature on ingots is going to be some evidence of a former meniscus (that curve of the surface that contained liquids have near the edge) where the liquid steel met the crucible wall...here are two real ingots, three crucible shapes and some steel shot from a ball mill, you can see the complete lack of similarity!

[Jens Nordlunde]

Jeff, Thank you very much for your post and the pictures.
Form this, there is no doubt what mill balls look like, so you have cleared that problem very well - once an for all .
Jens

[Oriental-Arms]

This is not an attempt to prove that these are wootz ingot or mill balls. It was discussed many times in several forums so I will leave it to the expert to decide. But since I was offering for sale few of these wootz/mill balls I feel I should share with you some facts and findings
I sacrificed one of this balls and submitted it to the good hands of Giora Biran, a blacksmith and a friend and this is what we have done:
The ball was cut into two halves with a disk and one of the faces flattened.





(Please note the crack in the center, also known as “pipe”. I will refer to it later.)

One half was heated to about 800 degrees and hammered down (in several heating cycles) to a flat bar shape:







One face was polished and etched to reveal a very clear pattern:



A small part of the bar was further forged to a small kitchen style blade (more and bigger blades are being worked out now), polished and etched:

[Oriental-Arms]

The Facts:
1)These balls are definitely coming from India. They are supposedly coming from an old armory but I can not substantiate it.
2) In the pile of several tenth balls that I have seen, many were of quite a symmetrical shape, few of non regular shape and all has the depression on one side.

The findings:
1) These balls were cast in a crucible. The depression and the “pipe” seen on the cut ball is very typical to what happens in the cooling process in the crucible.[br]

2) It is hard steel. We did not measured the exact hardness but Giora estimate it to be (after hardening) around 60

3) The pattern is clear and very similar to what we have seen on Old Indian wootz blades.

The open questions:
1) To start with, why to use cast steel ball for milling? It is far more common to use white cast iron for this task. It has a harder shell and it is definitely cheaper. The milling process require hundreds of balls, so all were cast each in a separate crucible ?? It is quite expensive.
2) In the early 20th C. (the age suggested in a previous thread for this balls) perfect shape balls were easily available, from a variety of materials and sizes. So again why to use crucible cast steel balls?
3) After a short while in the drum the mill balls will definitely get a non regular shape (but will never have the depressions we see here). In the pile of balls I have seen most of the balls had a perfect symmetrical shape. Does this mean that they are all un-used? Below is a photo of two mill balls I personally collected from an abandoned lime stone quarry (abandoned in the 50th). They are made of cast white iron and has the typical shape after use

[br]
4) The chemical composition of the balls may be a key to answer many of the questions. I am planning to do it and I will gladly report further findings

p.s: I had a private correspondence with Jeff Pringle regarding this issue. We are not in agreement and I hope he will post here his opinion.

[Richard Furrer]

I feel I must put my foot in here as well.
I was sent one of these ingots by Artzi many years ago I have not forged it as I said I would..it is still in ingot/ball form and I am shamed for not getting to this sooner.
I will have it chemically tested for elements.

While in India I saw many of these at a friend's shop in Udiapur and asked for a sample..it had 14% chromium when tested and did forge out to a nice pattern.
I will post images when I locate them. Some of these balls were as large as oranges others as small as grapes.

Ric

[Jeff Pringle]

Yes, we have a difference of opinion on these
Regarding the facts:
1) They also come from America, so origin is immaterial
2) The shape is not consistent with ancient ingots, so symmetry or depression also does not matter

Regarding the findings:
1) Definitely NOT cast in a crucible. The depression is the wrong shape to be derived from solidification shrinkage, the internal porosity is in the wrong place to be associated with the depression.
2) & 3) also immaterial

Regarding the open questions:
1) Choice of grinding media is governed by hardness and specific gravity of the material to be crushed, there is no reason to think cast iron is more common. Several types of cast steel shot are commonly available.
2) Because we have evidence of cast steel being used, it clearly must be one of the economically viable options, no need to ask why.
3) This is immaterial, since there is no reason to think they are ingots, why speculate on how they wear away in the mill? But there is no reason to assume the process is not random, generating symmetric and asymmetric forms.
4) This will of course be a good idea!
I admit my opinion is colored by having first run across these in a very non-wootz context, but the shape of the ones sold from India and some of the ones I found at a mine in the US are identical.