Tanto in Shirasaya (National Treasure)
Signature : Kaga Ju Masamine Sakuno
Mizunoto Ushi nen 8 Gatsu Hi (August 1973)
(We divide 4 sections for each sword as Saijyo saku, Jyojyo saku Jyo saku and regular saki)
This sword belongs to Jyojyo saku ranking.
The blade has top quality polish
Habaki : Gold foiled double habaki.
Blade length : 27.4 cm or 10.78 inches.
Sori : 0.2 cm or 0.07 inches.
Mekugi : 1
Width at the hamachi : 2.78 cm or 1.09 inches.
Kasane : 0.5 cm or 0.19 inches.
Era : Modern times. 1973
Shape : Wide and thick nice shape Tanto. There are Bo-hi on both side.
Jitetsu : Ko-Itame Hada well grained with Jinie attached. The Jinage is blackish and beautiful.
Hamon : Ko-Nie Deki, Sakasa Choji Midare with deep Nioikuchi. There are many Ashi.
Special feature : Sumitani Masamine, born Sumitani Yoichiro in 1921 was a swordsmith in Ishikawa pref.
Major in mechanical engineering and graduated from Ritsumeikan university in Kyoto,
he entered the researce institute of Japanese sword on the campus in 1941 and learned under Sakurai Masayuki,
the Second son of a famous swordsmith Sakurai Masatsugu.
After that he moved to Onomichi city in Hiroshima pref.
And learned forging and polishing sword at Kokoku Nihonto Tanren-Jo with his sworn brother Yokota Masamitsu.
In the postwar Japan, Masamine set up his own smithy named Sanryutei in 1956 and studied Bizen-den.
He forged special swords to dedicate the Ise-jingu shrine.
He became a Mukansa-tosho and a judge of the annual sword-making competition held by NBTHK in 1966.
In pursuit of Bizen-den, he completed especially choji-midare hamon called Sumitani-Choji.
He also studied old iron manufacturing in Kamakura period and reproduced classical texture of jitetsu.
He has made sword of Royal family such as Princess Mako and the Crown Princess Masako.
Masamine was designated one of a preservers of Important Intangible Cultural Assets,
popularly known as Living National Treasures in 1981. He passed away in 1998.
This blade looks like Aoe. This is Sakasa Choji Hamon great work.
Aoi Art estimation paper : whole Oshigata.