Previous answer is
Mumei(unsigned) attributed as Mino Senjuin
Special feature : According to NBTHK shins, the blade was judged as Mino Senjyuin school.
But the blade is quite well bizen jigane with utsuri and hamon is also different.
But the boshi is attractive Yamato school active hamon.
The founder of the Mino senjyuin was Yamato province and moved to Mino
and made swords by convention of Mino and Yamato senjyyuin style.
The kissaki hamon is more longer like Nanbokucyo style.
The sword is well grained Jigane even though some kizu around monouchi area
and nice Cyoji midair hamon.
Mino senjyuin school continued to late Muromachi period.
The sword is more than 72cm and nice jigane and hamon not get tired of looking at this sword.
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Appraisal Quiz #266 (November 15th, 2013)
Who made this sword do you think ?
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Hints. ※The picture will be enlarged
Blade length : 71.1 cm or 27.99 inches.
Sori : 1.0 cm or 0.39 inches.
Mekugi: 2
Width at the hamachi : 3.00 cm or 1.18 inches.
Width at the Kissaki : 1.76 cm or 0.69 inches.
Kasane : 0.57 cm or 0.22 inches.
Shape : Regular size width and thickness. It is shallow curve katana. There are some suriage(tang cut shorten) on the nakago.
Jitetsu : Koitame hada well grained with jinie attached. It is clear jigane.
Hamon : NIe base gunome midare hamon.
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