Actual example to make a Norishige like appearance on blades, tachi and
wakizashi
2008 November
We have a chance to see the steel for Dai-sho blades under forging. Dai-Sho
means long and short.
The steel block has completed the fold welding work. It is made from several
quality of steels mixed complicatedly, in order to expect a Norishige like
appearance.
The steel block is divided into two pieces, one for Dai blade, the other for Sho. Then they are constructed as the cutting edge of the blades. So this Dai-sho is going to be made as sisters.
2009 January
The core steel for the blades are forged up. Then the core steel and the
outer steel are constructed to one block by Kobuse style, and roughly drawn out.
The steel for Dai

The steel for Sho

2009 March
The steel bars are drawn out to the length for the blades.

They are shaped with hammer.
Dai

Sho

2009 April
The Dai and Sho blades are shaped with plane and file.

The blades are tempered in a silent night.
They are still on the temporary polish to see the result of tempering work.
Curvature has occurred on the both blades.




2009 September
The foundation shaping has done.
2009 October
The smith made the double narrow grooves on the blades.
2010 November
The both blades are polished up. The Dai is by the modern style, and the
Sho is by the classical style.
These blades are sisters, but their characters are not the same. The tachi
has Norishige like appearance, and the wakizashi doesn't.
Now we can study them comparing the difference.
Tachi
blade length 78.5cm, curvature3.0cm, thickness at the base 8mm, width 33mm
Wakizashi
blade length 53.6cm, curvature 1.4cm, thickness at the base 8mm, width 33mm
Tachi
Wakizashi
Consideration
The steel layers must be the same on both blades, because they are sisters
those are made from the one steel block. But the appearance of the steel
are quite different, as no one may not find that they are the same steel.
The tachi has a large layer pattern with visible jinie (steel particles),
even in the hamon area. On the other hand, we can't recognize such a large
layer pattern on the wakizashi. The steel layer is not visible, it looks
full of tight jinie. The difference of the appearance is a difference of
steel grain. It is not a difference of layer pattern. The grain of steel
particles is effected by tempering work.
Tachi
Wakizashi
The difference of grains on the same layered steel suggests us the mechanism
how nashiji-hada is brought up. (=> Nashiji-hada)