The blade was polished.
Habaki : Gold double foiled habaki
Blade length : 70 cm or 27.57 inches.
Sori : 2.3 cm or 0.9 inches.
Mekugi : 2
Width at the hamachi : 2.95 cm or 1.16 inches.
Width at the Kissaki : 1.73 cm or 0.68 inches.
Kasane : 0.62 cm or 0.24 inches.
Era : Late Kamakura period.
Shape : Oosuriage mumei blade with bohi engraved in both the surface and the back.
It is thick and wide and the sori is deep. Boshi is kokissaki style.
Jitetsu : Koitame hada well grained with nashime mixed with jinie attached.
Hamon : Konie base, suguha with deep nioiguchi . The ashi is soft on the edge of the ha.
Special feature : Niou is a swordsmith from Suou whom was originally found by Niou Kiyotsuna of
Yamatonokuni swordsmiths has moved to Suou and got influenced from their neighbors Bichuu Aoe.
JIgane is thin and grained soft feeling best quality jigane.
The katana is from Kamakura period to Nanbokucho period.
The jigane is wonderful and it is highly valued.
NBTHK Tokubetsu Hozon Paper
Aoi Art estimation paper : whole Oshigata.