About metallurgical methods on forging swortds

Subject:  Re: whats the best type of metal for razor sharpness that cuts silk?
Date: Fri, 9 Feb 2001 21:40:25 -0800
From: homeoffice2 

A couple of days ago I thought I saw a reply about a
 special type of metal that was best for the whole drop
 a silk scarf on a blade test.Can someone expound on
 this a bit more?
  I know there are several types of katana, some made
 for armor (more blunt edge), some made for street
 fighting (sharper and shorter) and some styles made
 for temples and aristocrats. Cant Japanese katana be
 forged and polished for a better than razor sharp edge
 that the whole scarf test requires?


in a word...........no

The type of edge that is created in a wootz product that is cold forged
cannot be duplicated by layered pattern welded Damascus steel, nor the
Japaese method of forge welding. The crucible method that creates wootz
steel creates a crystalline dendritic structure. These dendrites produce a
very, VERY sharp microscopic serrated edge. This structure would all but be
destroyed by the japanese methods of forging. Much research has been done
(by a VERY small group of men) on the dendritic structure and how to
preserve it through the forging process.  It is a difficult and timely study
and almost completely unkown among metalurgists. The descriptions of which
are entirely unsuited for this medium. Suffice to say ,there is nothing that
can be done to the granular structure in the Japanese product to produce the
same results. Further, your comment about  a polished  "better than razor
edge" Katana would in fact be going full speed in the WRONG direction. The
more you polish that type of edge the more it will NOT separate the dropped

As an aside, David Boye has developed a similar method in casting knives out
of stainless steel and cobalt in ceramic molds. And has been doing so for
decades. Upon cooling a dendritic structure is achieved. The knives cut like
crazy but they lack the Wootz hyper-ductile (read flexible) properties. In
fact they are known to be brittle and will not sustain much flexing. Which
is not required of kitchen cutlery. Morover, most of  his knives are heat
treated martensitic steels. The Wootz steel was not heat treated this way.
Those looking for martensite will not find it. That is why the earlier
comments about a hamon on Wootz steel are also false. If you were to try,
the graphite would precipitate out of the carbon matrix and give you one
wallapalooza of a brittle blade.This in conjuntion with a carbon content
upwards of 1.75%-2.00 %. Would make it , upon hardening more like cast iron
then steel.

I have written several longer essays (me writing an essay what a joke). Lets
say I managed to mumble through several pages on steel in this thread on
About steel for swords