AS21097-Katana: Koyama Munetsugu Saku

Katana in Shirasaya(NBTHK Tokubetsu Hozon Token)

Signature :　Koyama Munetsugu Saku
Tenpo 10 Nen Shogatsu
Oite Senju Yamada Gosaburo Tata Dotanbarai 固山宗次作

Fujishiro To-ko Jiten: Shinshin to:Jyo Jyo Saku:Musashi.
(We divide 4 sections for each sword as Saijyo saku, Jyo-jyo saku Jyo saku and regular saku)
This sword belongs to Saijyo saku ranking.
The blade was polished by high ranking polisher.
Habaki :　Gold color single habaki.
Blade length: 63.6 cm or 25.04 inches.
Sori :1.8 cm or 0.71 inches.
Mekugi: 2
Width at the hamachi: 3.03cm or 1.193 inches.
Kasane :0.75 cm or 0.295 inches.
The weight of the sword 605 grams.
Era: Late Edo period Tenpo 10 Nen Shogatsu.
Shape : The blade is Hyobu Kukuri style regular widthm thickness with deep sori and sharpened Shinoki ji.
Jigane: Koitame hada well grained with jinie attach very clear texture.
Hamon: Konie deki with deep nioikuchi and togari gunome mixed overlap these Hamon to the end of Kissaki. Bo-shi is komaru and Yakisage.

Special feature: Bizen suke Koyama Munetsugu was born at Rikuoku Shirakawa as the third son of Koyama Munehira. He made swords as a swordsmith of
Shirakawa Matsudaira lord. After that, he moved to the Kuwana clan, and made swords in Azabu Nagasaka. He made swords during End of Edo period to Meji period, so his swords style also changed many times, but the base is usually Bizen-den, Jigane with Nioikuchi, Hamon is Choji Midare.

From Aoi Art: Koyama Munetsugu was friend of Yamada Asauemon and many other cutting testers. Most of his sword was engraved Saidan-Mei. From this sword, we can see the sharpness of his sword. The sword is Tempo style and the shape is Shobu style, Sori is deep, Shinogi was shaved deeply and Mune is thin. All of these are features of well-cut sword.

NBTHK Tokubetsu Hozon Token
Aoi Art estimation paper: whole Oshigata.