Technical writing
 

JIM
Way off the subject of this thread however your comment to
Ann about her great writing skills reminded me of a time a long ago when I was involved in helping write a paper on the Nuclear water chemistry at a Nuclear Power plant.
The words that I used were not acceptable, reason was that the paper had to be written to the most knowledgeable person in the field and had to be written "over his head", all for impression sake and not to convey any information/knowledge to the lay public.
Ann has the ability to convey information to us dummies ( me that is) and I thank her as well as you for it, you also have the ability to not only convey information in understandable terms but to also smooth the feathers of the forum folks from time to time.

Will be back on subject matter when I return from taking my wife to the SEC woman's basketball tournment.
Be back next week
Gene

The problems I see is that:
1. The magnetization depends on two unknown factors - how non-uniform the steel is and what kind of fields the sample was exposed to. Lighting, wielding machines and subways all produce significant fields, capable of magnetizing pieces of iron.

So at least two different experiments should be condacted, unless you are interested in non-uniformities alone. Then the reasonable thing is to ask a steel metallurgist, but I think they actually measure permeability - they take not very large field, apply it to the sample and see what kind of magnetization is produced - it's supposed to be uniform if for example you apply the field along the easy axis (parallel to the sword?), but only if the sample itself is uniform.

Another way is to use X_Ray scattering or conductance or chemical tests - I think all these techniques are been used in the steel industry.

another interesting thing would be to try to achieve the true ground state in the sample by heating it up and cooling it down in the absence of external fields, with probably some random ac fields being applied to the body.

Concerning shape-dependent demag factors, there are programs like rkmag and oomf that allow one to simulate the magnetizations, so you should get the approximate picture of what kind of state you should have.

2. To Mare Rosu:

Thanx for the pictures,
The thing I would consider to be interesting is a conductance test. I don't think it can fire up with a simple resistometer, but it can be that if you place probes at about 5mm from each other on the dagger and move them alongside the dagger's surface that you will be able to see a significant change in the resistance along some set of points, which is possibly can be connected to the changes in the metall itself.

The problem is that not all steels are ferromagnetic, but they are all conductors, so unlike magnetism, you should not see a lot of difference.

P.S. I'm not a steel guy and not an experimentalist, so I really should not give any advices.

Sincerely yours,

K.Rivkin

I always thought ingots were like the round one you show Gene, but after having read Ann’s article in Minerva Magazine No. 13, issue 4, 2002, I was wiser, ingots can be found in many shapes and sizes, the ones made in Merv weighted according to Ann’s article about 2 kg.
Gene how many different ingots do you have, and do they have the same weight?
Is there any writing or marking on them? I remember to have seen a picture of a round ingot with some writing on it.

Ann, do you know if the shape of the ingots was a kind of ‘trademark’ for a region?
Would the kind of clay used, ‘porcelain’ clay vs. other types of clay, have any influence on the ingot?
Maybe we should start another thread on ingots.
Somewhere I saw, that in one of al-Biruni’s (973-1048) books, I think it must be in Kitab al-Hind that he describes iron/iron production(?) in India. Do you know if it is in this book?

Jens

Words? on Wootz
 

JENS
This is the link to the wootz bar I had and made it into a Bowie by Al Pendray and also tested by Verhoeven. The end with the inscription is still with Pendray, at least it was the last time I saw him.
http://www.vikingsword.com/ubb/Forum1/HTML/002326.html
Gene

Gene, the ingot you show on the link seems to be round and flat. The one I saw a picture of was shaped like the round one you show on a picture on this topic, but larger - I think. The writing was on top of it, and looked, as I recall it, like the writing on the one you show on the link.

Jens

Thanks Gene for the generous offer! :) I will take you up on it as soon as I have time to spend doing research. Right now they would just be used as paper weights, until I finish lecturing this term. I will be looking for ingots and blades to include in the book. Where did you get the ingots from?

A small knife I have, in a scabbard together with a katar, is very magnetic, but the katar is not.
The picture to the left shows the tip of the blade, and the one to the right the compass at the base of the blade. The small knife is made in the first quarter of 1600, the katar is newer.

When magnetic moments are positioned alongside a line (good approximation for thin swords), there are basically two stable configurations - all magnetic moments are oriented along the line, parallel to each other, or they are all perpendicular to the line, and anti-parallel to each other, i.e. +-+-.

What you have most likely shows that you physically have different steels (most likely phases or chemistry) at the tip and for the rest of the blade, so you've these two macrodomains anti-parallel to each other.

Rivkin, thank you for your answer. I understand what the words, but I have a feeling, that I don't understand the whole meaning. I understand, that when we have come as far as we have, and want to go further, the language is likely to get more complicated. Is it possible for you to explain it in another way?
Here is a picture of the katar and the little knife.

In a very approximate manner:

When magnets are dropped into a narrow, long box, they naturally prefer either to align all parallel to each other parallel to the long side of the box, or anti-parallel to each other (with anti-parallel polarities) and perpendicular to the long side of the box. In both cases the magnets will lie parallel to the magnetic field created by other magnets.

So your configuration is most likely due to the case that at the tip you have some anisotropy , most likely due to changes in steel's chemistry or physics (phases).

Just my 2c.

Andrew, thank you for making this tread a sticker. Some collectors collect weapons and keep it at that, a lot of others are also interested in the ‘background’ story, how was the ingots made, why did the pattern appear/disappear, why did smiths have difficulties in forging the ingots, why are some of the blade magnetic, things like this line. I think the thread ‘Magnetic weapons’ answers a few of these questions, and hope we can get more questions answered in the future.

Thank you Rivkin, for ‘translating’ you mail for me – I think I now understand what you mean.
The ‘uncomplicated’ subject ‘magnetism’, has proved itself to be anything but uncomplicated, but I find the discussion very interesting, and hope, the other members do too – I for one has learned quite a lot, although I did not understand all the mails.

Jens

Hi Jens. Like many of us, I've been following this thread with interest, if not with complete comprehension. ;)

The technical information contributed by posters like Rivkin and Dr. Feuerbach (and others!) is outstanding. Gene's "field work" has been terrific as well.

JENS
In an earlier post I stated that the tip end compass was pointing in the wrong direction, and I did not know why.
I think I have an explanation for the confused compass.
While I was doing the Case knife test that was suggested by FEARN I inadvertently got the compass to close to the magnetic knife holder and it switched the needle magnetic field, to where outside the house the needle pointed South instead of North.
I did demagnetize the compass using a demagnetizer and then re-magnetized it back to "normal".
The moral of this story is be careful with your compasses and strong magnetic fields from any source.

ANN
Your most welcome on the wootz ingots/bar. Just let me know when you are ready for them. :)
You also asked about where I got the wootz ingots. All of the items came from Oriental-Arms, Artzi. My first wootz ingot, the one that has the inscriptions on it was reportedly to have come from the Alwar armory.

RIVKIN
I did try to determine the conductance of the blade for any variances but the meter I have is just not sensitive enough to detect any change along the blade.
I did find something unusual, the cast bronze? hilt has a ~1 Meg Ohm resistance from the blade to the hilt end, indicating some sort of resistance between the two. :confused:
Gene

Gene you have lost me - way out in the wilderness - do you think you can find me again?
What does - '~1 Meg Ohm resistance from the blade to the hilt end, indicating some sort of resistance between the two.' mean?
Really, the whole thing is so easy, so why do you explain it in such a difficult way - sorry - I think have an idea why. :o .

Jens

Questions,Questions, Questions
 

JENS
I do not ask hard questions. You are the one that started all of this "Magnetic Weapons" hard question stuff :p
What I am saying is that the metal handle is not directly connected electrically to the blade there is a one million ohm resistance between the two. In other words the hilt is not conductive to the blade, it is insulated form the blade so much so that if you were to energize the blade and you were to hold just the hilt you would not feel the anything from the blade being energized. Just another mystery of the dagger I call Mysore.
I hope this get you back out of the woods we need you here to ask the hard questions :)
Yes, your idea/thinking has merit, I have said before you are very astute :rolleyes:
Gene

Thank you for the ‘translation’ Gene. I am still a bit confused, but on a higher level :rolleyes:.
Does the insulation also mean anything when it comes to magnetism?
My questions can’t be that difficult to answer, as most of them have been answered :p.

Jens

INSULATION
 

JENS
I have failed to follow up on my closing part of this great thread of yours.
I have no idea as to what effect if any the insulation of the hilt has on the weird magnetic properties of the dagger I call Mysore.

I also stated I would take some pictures of the reversed pointing compass (points South not North), caused by the strong magnetic field of the knife holder in the test suggested by FEARN.
The first picture shows the South pointing needle and the second one is after I demagnetized it and magnetized it back to normal and the third picture is the little demagnetizer I used for the process. The little hole is to place a blade of screwdriver into to make the blade magnetic.

I must commend you on this excellent idea you had on the question of "Magnetic Weapons". It was for me a great learning process and also great fun, a hard to beat combination!
I just hope you did not get to upset with me on my Southern kidding to you on the "hard questions" comments, I made, all in jest, all in jest. :D
You did good! :)

Gene,

Your dagger (Mysore) is fantastic. Thank you for sharing it, and your results.

Great thread.

Andrew

Gene, I did not, quite honestly, think this thread would be as big as it is. Although it was a surprise to me, there have been many most interesting posts. Your experiments, your pictures and your humour has made sure, that the thread did not end up being too dry – thank you very much. Also thank you very much to all the other contributors for valuable information’s.

It was very nice of Andrew to make it a sticky, as I think many more than the contributors have been reading on the thread and learned, that there is more to a sword/dagger than a blade and a hilt.

Jens

Hey Jens, what type of knife is that next to the katar and how old is it?

Hi Battara,

The katar shown has a funny history. I got it almost thirty years ago, in England I think, and a year or two ago I showed a picture of it to a friend, shortly after he came back with the following story, after having visited a friend of his, who has some books about English cutlers. They agreed that it was hardly an Indian mark on the little knife – but it could be English – so they started to look through the books: The small knife has a cutlers mark in the blade. The mark belonged to John Jencks, 1576-1625. He got his cutlers mark in London 1606-7. He was born in Blackfriars and died in the Tower of London. His mark was a thistle and a dagger.

For further study see: J.F.Hayward: English Cutlery. Victoria & Albert Museum, 1957. Masterpieces of Cutlery and the Art of Eating. Victoria & Albert Museum, 1979.

I forgot the cutlers mark.

In the book ‘The Arms and Armour of Arabia’, Robert Elgood quotes G.C.M. Birdwood, who in 1880, in ‘The Industrial Arts of India’ wrote: ’20 miles east of Nirmal, and a few miles south of the Shisha hills, occurs the hornblended slate or schist from which the magnetic iron used for ages in the manufacture of Damascus steel, and by the Persians for their swordblades, is still obtained.’

Further more it is mentioned, that the steel was superior to the English, and even to the best Swedish steel.

Nirmal is situated about 280 miles from Hyderabad – should anyone star to wonder where it is.

If the steel, which Birdwood refers to, is lodestone, one of my earlier questions is answered: ‘Was lodestone used for weapons?’ The answer must be yes – definitely.

But it was not all lodestone, which is/was magnetic, it took a lightening to make it magnetic. If a lightening hit a lodestone ore, would the whole ore be magnetic – or only part of the ore?

Jens

Hi Fearn,
Yesterday I saw that the compasses were made like a fish (hollow I guess) swimming on oil.

Jens

Blades and magnetic fields
 

Hello all,

Jens suggested I check out this thread, and it's quite interesting. I am a custom knifemaker, and do everything from stock removal to forging blades, to hand forging my own Damascus (pattern welded) blades on occasion. I harden them myself, using various media, and get good results. However, I do not perform any specific processes to induce magnetic fields in any of them.

The topic made me curious, so I grabbed a compass and moved it along an assortment of my knives. The results were widely varied. Some hardly moved the needle, some made it spin wildly, and some spun it in one direction, then back in the other. Not sure what this says about the topic and folks' opinions, but it seems, for me at least, to simply be a random phenomenon.

Just my 2 cents.

Michael
www.radharcknives.com

Interesting thread, indeed. I had forged a strong magnetic tanto blade too. It doesn't show any magnetic property until I heat treated. I accidentaly tempered it on a hot plate. The hot plate was for laboratory purpose with a magnetic stiring device. After tempered, the blade has so strong magnetic property that it can pick up a few 3 inches nails.

This phenomenon is also sometimes exhibited in stainless steel restaurant silverware of low to moderate quality ; the stuff is just stamped from sheet metal ; go figure .. :confused:

Magnetism and knives
 

Huh. Peculiar for sure. It may very well be, in knives at least, relative to the heat treatment processes. You mess with the magnetic field, indeed, that's the simplest way to know when a steel is at the correct temperature to quench it, in order to harden the steel. It's called the critical temperature, and when it is reached, the steel undergoes a structural change, as evidenced by the fact that it loses it's attraction to a magnet run along the hot blade. When it's up slightly past 'non-magnetic', depending on the steel, you quench it.

As an aside, I align my quench tank so that the blade is pointed towards magnetic North, and quench them held horizontally, moving them back and forth in a stabbing motion. Some claim that the mag N thing is voodoo, but my blades universally harden up well, with almost no warpage whatsoever. So, it works for me. LOL!

Michael
www.radharcknives.com

..... just a thought.
It may be interesting to get photos of the 'lines of magnetism' for some of the swords, knives and daggers mentioned in this thread. By placing white paper over the blade (which is placed on a non magnetic background), and then sprinkling iron particles on the paper. Lines of magnetic force will appear, as the iron filings align with the field (magnetic) that surrounds the blade. Assuming the possibility that some of the magnetic properties of the blades were deliberate, it might help to see what patterns are produced and aid ideas as to why this is done.

One other thought is, blood is highly concentrated with iron (in haemoglobin), seeing as most blades were used or designed to 'draw blood' perhaps there’s a connection there.........

Hi Katana,
Maybe you should go back to the start and look through the mails - then you will see that it has been done.

Jens

That'll teach me not to skip through threads, my apologies. :o

Don't worry, I do it now and again as well:).

Jens

Attached is a numerically simulated magnetization in 15x2cm FeNi sample, rapidly cooled from Curie temperature.

a. The magnetization is parallel to the local direction of the magnetic field, therefore the paper and iron dust would procuce a similar picture if placed on top of this sample.

b. Equilibrium configuration is a result of such things as a competition between exchange and dipole-dipole interactions for a given shape.

c. The loss of precise magnetization is more or less a smooth function of temperature. Since Fe has Curie temperature of about 1000K (700C) it is not that noticable at the room temperature, but becomes an essnetial issue when you heat any sample to 500-600C. Initial magnetization, i.e. whether magnetized or unmagnetized iron has been used, becomes at this point mostly irrelevant.

d. The attached simulation was performed in the absence of external fields. Earth's magnetic field is truly irrelevant since it is extremely small; on the other hand the presence of other magnets like magnetized anvil and so on could have made the magnetization to be more uniform.

Richard Burton in his "book of the sword" tells us that ancient greeks believed magnets to posess healing properties and weapons, made from magnets to be extremely deadly.

Hi Rivkin,

I just saw your last two mails. No 114 I only understand part of, but that is not your fault, and what I understand is interesting. The last mail made me remember something from my childhood – I was told that if someone were cut with a magnetic knife, the wound would heal very slowly, if at all. The Indians seemed to mean that weapons made of lodestone, had a special meaning/force, as did many of the other peoples living in the area.

Thank you very much,

Here is what I found rereading my books:

Adzhaib Ad'Dunia "The miracles of the world"
"Indians have a miracle steel... Magnets do not attract it...If you make a sword out of it and kill someone with it, no blood will spill, the arrows made from it can penetrate stone, it does not get hot in fire... It is used to make swords of indian rulers... they do not export it, searching all the traders for it when they leave..."

I tried a search for the book, but without any result. Can you tell more about the book?

Sounds like a strange metal, I wonder what he was referring to?

All very interesting. Thanks Rivkin for the reference...I will try to get it.
I am presently further looking into the "receipes" used for crucible steel production and the symbolism of the ingredients (rather than the strick material science of the ingredients). The use of magnetic ores, meteorites etc are all interesting additions. I am currrently trying to find out the symbolism of coral, as it is sometimes an ingredient.

From The Complete Dictionary of Symbols in Myth, art and Literature by Jack Tresidder
"Coral
Linked with healing power - an association based on tree, water and blood symbolism. In Classical mythology, the Mediterranean red coral grew from the blood of the Gorgan Medusa; after Perseus had rescued Andromeda from Cetus, the sea monster it is said that he laid the Gorgan's head down and immediately the sea weed turned into coral. Vasari illustrates this on a cabinet door of the studiolo of Francesco I (Palazzo Vechio, Florence) to indicate the precious contents. Coral was also thought to be a protection against evil. In Roman times, amulets of coral were thought to stem bleeding and protect children from illness or the fury of the elements, and coral necklaces were also popular medieval talisman for children. At one time, coral decorated Celtic weapons and helments. It was prized in India where jet black coral was used to make sceptres."

This is Eurocentric but maybe of some use to you.

All the Best
Jeff

Thanks Jeff, it is a start. Interesting how it is said to stem bleeding.

The only reference to coralls I remember is from Maqrizi who says that coralls are like steel in the way that like Allah made steel soft for David so he would make mails, coralls are a stone but can be made soft to make jewelry. Something like this :).

I did not like the "miracles of the world". It just has this small segment about weapons, the rest is about other miracles.