Tricks of Smiths
|What is a trick?|
|When I conceived this module, I
thought it would be large, possibly developing into a
link hub. I
was wrong. The reasons for this are manifold:
|Maybe a better way to address the
topic is to ask what kind of not-so-easy things ancient smiths obviously could
do, and what "tricks" they used to do it. Here is my list:
|The first point overlaps with the "tricks of the smelters and miners" to some extent but I won't go into this here.|
|Recognizing and Sorting Different Grades of Steel / Iron|
|A smith had either made the iron /
steel he worked with by himself in a bloomery furnace or he bought it from some
supplier. In the latter case the material may have resulted from three quite
bloomery iron /
steel from the first case always contained
slag inclusions. Moreover, the main alloying element might have been phosphorus
and not carbon. In any case, the distribution of carbon / phosphorous in the
bloom was for almost sure rather non-uniform.
We don't seem to know all that much about the second case. The famed Svedish "Osmund iron" that, surprise, turned out to be steel, is a point in case. Anyway, "finery iron / steel" might still contain slag inclusions from the way it was made, even so the cast iron it was made from was slag free. It was also likely to be rather inhomogeneous.
The crucible steel of the third variant was a relatively useless specialty of India / Central Asia / Persia as far as the normal smith was concerned. It had some merits for some special products (like sword blades) but was too hard, too expensive and too difficult to work with for the everyday things a smith made and maintained.
Let's not forget an old rule:
|The typical ancient smith was a guy you knew. He lived and worked not far from you. I would guess that every town with more than 500 inhabitants had its resident black smith, often with the additional qualifications as farrier so he could shoe your horses. He certainly did not make swords.|
|The "recognizing and sorting" question thus has two parts. First, how did the normal smith deal with the task and second, what did the sword smith / specialist do?|
|The answer to the first part is
easy: The normal smith just had his suppliers that provided him with the normal
and most likely local stuff he knew. He might even have been part of the
suppliers when some smelting took place and he participated.
it didn't matter all that much if the quality of his wrought iron / mild steel fluctuated a bit for most for the products he made. It his wrought iron was not good, he could tell right away because it behaved wrong. Everybody who can wield a hammer can tell if a material is soft and ductile, hard and tough, or perfectly brittle, after all. Somebody who wielded a hammer all the time could certainly do considerably better.
|The second part of the questions is
what interests us. Let's first look at the Roman expert (of probably Celtic
decent) who made a complex pattern welded sword around 300 AD from
bloomery steel. He could work a bloom himself but more likely bought the stuff
from somebody else. What he needed was:
|What could a smith do to ascertain
that the pieces of steel he made or acquired were the right kind? The range of
|I have described some of those tests in more detail in the chapter about Japanese blade forging because we know what Japanese blade smiths did and still do for testing the quality of their starting material. We can only guess with respect to all the other ones.|
|Faggoting and Fire Welding|
|Faggoting involves copious fire
welding so I treat both of these topics in one paragraph.
The need for faggoting bloomery steel results from
| Faggoting is the only
way to overcome these problems. Fold, fire-weld, stretch. Repeat ten times and
you have 1024 layers now. Everything is rather uniform and some large
extraneous defects have been reduced to many small defects. Some might have
been removed (like voids).
So far the smith wouldn't need to resort to tricks, he just has to do his job. Tricks must come in, however, because faggoting involves copious fire welding and that is a tricky procedure for several reasons
|The more you fold and fire weld, the more uniform your iron / steel will get. But with every folding and welding less iron / steel is left and the number of welding defects increases. There is thus an optimum number of foldings that depend on the quality of your starting material and in particular on your skills as smith. Here your "tricks" come into play. What do we know about these tricks?|
|Next to nothing. Sprinkling some
"sand" (or flux) on the surfaces to be welded is a well-know trick.
What that might do I have described
elsewhere. Japanese smith
put some rice straw or the ash of rice straw on the surfaces to be welded. What
that is doing I don't know. Since rice straw is rich in SiO2 it
might be just a different way to put flux on the surface.
However, the ancients smiths must have know a trick or two that we have not yet unraveled. Suffice it to mention the so-called "white weld line" effect with its mysterious high arsenic concentration.
Only time will tell. So far there are far too few investigations in ancient (and modern) fire welding techniques and its precise working.
|Working With Wootz Steel|
|The two major tricks, unknown to the
European smiths who wanted to unravel the secret of the Indian / Iranian /
Arabian wootz blades in the 18th / 19th century, are
|So far so easy. But forging a rather brittle
material at low temperatures is not easy. Deform it too much and it cracks. One
trick that modern wootz smiths seem to us is to encase your UHCS steel in soft
steel. You grind off the soft steel after you are done with forging.
What kind of tricks the ancient wootz smiths had up their sleeves we don not know At least I do not know.
|I have a message here.|
Phosphorous Steel; 9.4.1 General Remarks
11.4.2 Blades of Viking Era Swords
11.6.4 Metallurgy of the Japanese Sword
10.3 Iron and Steel in Early Europe; 10.3.1 Technology Transfer and Trading
10.5.2 Making Steel up to 1870
Moravian 9th Century Swords
Iron in China
11.6.2 Making a Japanese Sword - Part 1
The Iron Carbon Phase Diagram
© H. Föll (Iron, Steel and Swords script)