The blade was polished.
Blade length : 69.09 cm or 27.20 inches.
Sori : 1.50 cm or 0.59 inches.
Width at the hamachi : 3.05 cm or 1.20 inches.
Width at the Kissaki : 1.90 cm or 0.35 inches.
Kasane : 0.65 cm or 0.25 inches.
Era : Late Kamakura period.
Shape : This blade is regular sized Katana with little Sori.
Jitetsu :Jitetsu : Itame works very well, and covered in Jinie. It is black Jitetsu called Kitaguni (northern area) Jigane.
Hamon : Koniedeki with rather deep Nioikuchi. There are much Ashi and sunagashi , small Kinsuji. Boshi is Hakikake style.
Special feature : Sadatsuna was swordsmith in Sekishu province,
and continued 3 generations.
It is generally believed that Sadatsuna the First was
a son of Sekisyu Naotsuna. Naotsuna has been counted among Masamune-juttetsu, the best brilliant ten pupils of Masamune in Soshu.
Sekishu province, present Shimane pref.
Sekishu province had been prospered by good quality iron, the clan forged excellent swords for generations.
This blade was appraised as Sekishu Sadatsuna by NBTHK Hozon Shinsa. On the Ji, some lose hada but not serious.
The blade is Koto and enjoy the sword.
NBTHK Hozon Paper
Aoi Art estimation paper : whole Oshigata.