National Geographic channel Sam sword

**KukriKhan** · 10-10-2007, 15:27

Last night our (US) Public TV aired a program call Secrets of The Samurai Sword, which sounds very similar to the program TosaInu referred to.

It was indeed fascinating, particularly the parts about the thousand-years-old method of smelting the steel, then fashioning the sword and tempering it. All of it done without a modern understanding of chemistry and physics; done rather through "feel", after centuries of trial and error.

The program riveted my attention for the entire hour, and I found myself wanting more - for example: I'd have liked to have seen who & how the iron ore was harvested (they referred to it having come from "beaches" but showed no footage).

And I was surprised to learn that the curve of the blade is a by-product of the tempering process - that it wasn't merely hammered out that way.

**Noir** · 10-10-2007, 16:03

Metallurgy has always been more of a black art based on trial an error rather than a science - even now days that steel production is carefully and reliably controlled with very small imperfections per average volume, these still do exist and actually account for material failures that have been known to be catastrophic (a whole platform in the North Sea failed due to one such imperfection 20 years ago or so).

Imperfactions center around slip planes that basically are due to irregularities in the way the Iron/Carbon atoms are arranged in space that might prove fatal under relatively low stresses since they open up the material in a zip like fashion. Swords need to be well above that failure mode - that is need to be much more reliable than structural steel, due to their smaller sections and thus much higher developed stresses in them.

Metallographic examination of katanas has confirmed that they are in fact the finest hand to hand weapons ever poduced in the history of mankind having more than a million alternating layers of iron and carbon in their microstructure (indicating nigh to perfect alloying) as opposed to a few tens of thousands found in the second best (Spanish medieval swords produced in Toledo).

In a more grim note, the "testing" process, involved cutting real fresh or alive flesh. There was an endless array of opportunities for the bushi to do so. In addition, endless tempering repetitive, precise hits were conducted in swords made by the master swordsmiths. Precision, repetitiveness and patience, those most of Japanese of virtues were responsible for the end result.

Social mobility was rare in medieval Japan and the dedication of the master/pupil relatioship as well as continuous civil wars guaranteed an evolutionary process in swordmaking that lasted for more than half a millenia -in Europe by contrast the continuous evolution of weapons and fighting methods as a result for the need to adapt to the opponents disturbed the continuity of such processes.

Noir

**Wasp** · 10-11-2007, 12:33

I don't suppose any of those shows are on the Internet so I could watch 'm?

By the way, loved that bit, Noir!

**Drisos** · 10-13-2007, 16:15

Originally Posted by Wasp

I don't suppose any of those shows are on the Internet so I could watch 'm?

I'm afraid not. You could try searching, though.

With a bit of luck you'll get the see the show again as a "herhaling" or you'll just see another show on the subject. When you look for it, it appears that the tv does actually has some good stuff now and then