Katana in Shirasaya(#48th NBTHK Juyo paper)
Signature : Mumei (Nio Kiyutsuna)
(We divide 4 sections for each sword as Saijyo saku, Jyojyo saku Jyo saku and regular saku)
This sword belongs to Saijyo saku ranking.
The blade was polished
Habaki : Gold foiled double habaki.
Blade length : 67.27 cm or 26.48 inches.
Sori : 1.8 cm or 0.70 inches.
Mekugi : 2
Width at the hamachi : 3.1 cm or 1.22 inches.
Width at the Kissaki : 2.1 cm or 0.82 inches.
Kasane : 0.83 cm or 0.32 inches.
Era : Late Kamakura period.
Shape : It is wide and thick Katana,it is with deep Sori and long Kissaki.
There are Bo-Hi and Soe-Hi engraved on both sides.
Jitetsu : Koitame-had with Jinie attach and slightly Utsuri appear.
Hamon : Nie Deki Suguha with Ko-Gunome Midare mixed.
And there are many sunagashi and kinsuji work.
Boshi is deep nioikuchi round shaped hakikake style.
Special feature : Swordsmiths of Ni-o school made the sword in Su-o province, present Yamaguchi pref.
In the Heian period, Sho-en, the manor in medieval Japan had been developed in Su-o.
Many fiefs of the Imperial Household, the Fujiwaras and the To-dai-ji temple also developed in that period.
It is thought that the reason why the sword influenced by Yamato School had been made there is the result of cultural exchanges between Kinai and Su-o.
The oldest Tachi of Ni-o school was made in1265 with the name of an era, the Bun-ei period.
It is in Itsuku-shima Shrine in Hiroshima pref. Next to Yamaguchi pref.
Swordsmiths of Ni-o school continued to make sword in the Shin-to period.
#48th NBTHK Juyo paper
Aoi Art estimation paper : whole Oshigata.