New sword 1B
Ken blade with straight layer pattern (Ken blade B)
Forging the blade
This time he tries a blade with straight layer pattern. So the steel construction is the sandwich style (three layer).
Fold'n welding work for the outer steel - Rough formed steel pieces are
picked up. Each of the pieces are formed with uneven quality in itself.
Some parts are hard, and other parts are soft. Some parts are rough and
other parts are dense. They are rather soft comparing with the core (edge)
steel. The steel pieces are welded to one block, and folded 8 times. Then,
it is turned 90 degrees to show the steel layer on the surface. And it
is cut into two pieces those become the both sides of the blade.
Making the core steel
It is on the half way of fold'n welding work. It has been folded 5 times,
and will be folded more.
The steel is covered with rice straw ash, and put into the forge again
to get the welding temperature.
The core steel is forged out after 13 times folding. It becomes the edge
of the blade. And this steel block is cut in two. One is for this ken blade,
and the other is the ken blade A. So, ken blade A and B are sisters in
the meaning of the core steel. =>New sword 1A
And then, the steels, core steel and two pieces of outer steel, are welded
together to one steel block.
Shaped by hammer work
The the blade is shaped by the plane and files. Then, it is a time to harden
the blade.
Heating and quenching work