This is a long and impressive katana by the Shintô smith Heianjo Yoshinaga (平安城義長). He worked in the Kanbun period (ca 1661) in the Osaka area. This is a long and robust sword that is in great condition. It has a nagasa (length) of 30.16 inches or 76.6 cm. The moto-haba (width at the base) is 1.31 inches or 3.34 cm and the saki-haba (width at the point) is 0.91 inches or 2.35 cm. This narrowing as one moves toward the point is a characteristic of the Osaka Shintô swords from this time period.
This is a thick blade with a kasane of 0.31 inches or 0.79 cm. It has a typical Kanbun sugata (shape) with a shallow torii sori (curvature) of 0.63 inches or 1.61 cm. The bôshi is somewhat compressed as one would expect and it has a ko-maru (small turnback) with a very short kaeri.
The jitetsu (grain of the steel) is a tight ko-itame ( wood grain) with areas of ko-mokume. There is masame (straight grain) in the shinogi-ji. The hamon (temper line) begins at the tang in a suguha (straight) pattern that quickly becomes a more slightly undulating notare. As it travels up the blade, it becomes more and more robust with areas of gunome expressed in a number of peaks and valleys. The nakago is ubu (unshortened with only one Mekugi ana (hole).
The full signature of this smith is Heianjo Minamoto Yoshinaga Kore (o) Tsukuru (平安城源義長造之). This sword comes with a nice set of Edo period koshirae as worn by the last Samurai who owned this blade. It also has a certification from the NBTHK who awarded it the rank of Tokubetsu Hozon Tôken (Especially Worthy of Preservation).