Hira Zukuri Daito

[hxv]

Greetings,

 

Why are daito in hira zukuri shape rare? Is it technically more difficult to forge and/or quench in this shape? I have searched in my reference books and on the web, but to no avail. Any insight is much appreciated.

 

Regards,

Hoanh

[paulb]

I am sure engineers here will give a better explanation but I think it comes down to optimising cutting efficiency and reducing weight. Introducing the shinogi enabled the smith to produce a more effective taper to the edge while maintaining the strength and rigidity of the blade. The larger the blade the more important this became.

Hira sukuri works realy well on smaller blades and for different applications to long swords.

I am told the most efficient cutting profile is shinogi zukuri with niku (clam edge) this can only be effectively worked with a shinogi in place.

[IanB]

Hoanh,  I once asked Yoshindo Yoshihara this and he said that he liked to make them but people are reluctant to buy them as are liable to crack. Apparently they can be OK for a long time and then suddenly 'Ping' and you have an hagire. I assume it is because there isn't the thickness a shinogi blade has to absorb the stresses.

Ian Bottomley

[hxv]

Thank you Paul and Ian for your insights.

 

Regards,

Hoanh