( Of much interest for any black smith in the field of making knife or swords )
One year ago I got my hand on what is called " Zanketsu " : a Katana cutter in 3 . The reason those great objects are cutted with a grinder is that in order to keep a sword in Japan you must have a licence. So any person not been abel to have a licence will have its katana cuted in 3.
Any way out of those Zanketsu part I forged a collection of bracelets which turned out to be very nice jewellery after a long life of violence. Not always easy to trace back the origine & date most of the bracelet that came out originate from forged katana that date around 300 years ago up to more recent piece made for japanese officer during the second world war. Those last one are made from different steel and this you feel when forcing it. At that time I did not try to requinch the bracelets and experienced the hardnes of the steel with the grinder when cutting them appart. ..
Eventually this year I had the chance to attend a deomstartion and lecture at Jidayubori Park’s Old Farm House Garden, in Setagaya , Tokyo by one of the last black smith that is stile involved in the making of katana the ancient way. This was quite instructive about a few details that make the way of the japanese. Like the use of pin charcoal cutted at a certain size and a very fast way of anealing the quinched blad. The quincking of the blad is the smae of what is applied to a blad of simple steel, bassed on a knwoleage of the temperature and color of the metal. The sneaking of the quenched blad was very simple and fast in apparence. This happent by knowing the correct temperature according to the way water evaporate when sprinkled on the steel hot blade. From what I could observe it is basically the time that the water takes to evaparte away. It is something that happens very fasty in a mater of a second or lest . It is really the sound and time it take that determin the proper point of anealing. Only experience can teach you this. It is a very fast way but experience and knwoledge of temperature is crucial at that point.
No effect with HSS drill , then tried the tungsten drill which as well did not work, so we turn to the dyamon drill which even did live a mark on the steel...
After all those year of forging different blads and steel I had never encounter any think like that. Every body in the workshop that night were left speach less. I was having in my hand a steel stronger that dyamond ! It is only after experiencing this that you can understand the great beauty and strength of this unique metal and craftman ship requiered to make a Samurai sword. A blad at it ultimate perfection, stronger that dyamond but stile having a certain flexibility. So finally I had to unquinch the blad I made to do quinching and anealing prosses the ancient way. Finally I came out with two tantos stronger than dyamond but still whit a certain flexibility. One that I offered to my Japanese Sempai and the second one for my self. One more little detail that was quite surprising when working with this steel was that when unquiched this 300 year old steel was extreamly soft ...