Description
Authentic Nihontō Japanese Sword Katana Signed by Bishu Osafune Sukemitsu 備州長船助光 NBTHK HOZON TŌKEN Certificate
The 備前助光 (Bizen Sukemitsu) of the 室町期 (Muromachi period) is believed to have begun around the 應永 (Oei) era and continued through the 永享 (Eikyo), 文明 (Bunmei), 永正 (Eisho), and 天文 (Tenbun) eras, spanning five generations.
This sword, judging from its shape and form, is likely from the third generation. The difference in width between the base and the tip is well-proportioned, and the middle tip is slightly extended. The 地鉄 (jigane) is a well-forged 杢目 (mokume) mixed with straight grain, featuring a faint midare-utsuri. The 刃文 (hamon) is a straight suguha with small midare, predominantly nioi-based, with abundant ashi forming small gunome and choji, and prominent sunagashi. The variations along the blade's edge and within the blade are reminiscent of a famous old sword from the 鎌倉期 (Kamakura period). The 帽子 (boshi) on the front side is slightly burnt down, while the back side is straight with a generous round return. Observing the 茎 (nakago), there are traces of curvature adjustments made over time, reflecting the sword's history.
There are forging lines visible near the base on the front side, but these can be made less noticeable with fine art polishing. We highly recommend having it re-polished to fully enjoy its beauty.
*There is some glue separation at the end of the 白鞘 (shirasaya scabbard). The handle (tsuka) has some looseness.
Bare weight: 654 grams.
Nihontō Information
| Name 名称 | 備州長船助光 - Bishu Osafune Sukemitsu |
| Blade Length 刃長 | 二尺二寸九分三厘強 / 69.5 cm |
| Sori 反り | 六分三厘弱 / 1.92 cm |
| Blade Width 元幅 | 28.4 mm |
| Blade Thickness 元重 | 6.2 mm |
| Tip Width 先幅 | 物打22.8 mm 横手位置19.5 mm |
| Tip Thickness 先重 | 物打5.4 mm 松葉先4.4 mm |
| Mekugi-ana 目釘穴 | 3個 |
| Age 時代 | 室町中期 The middle period of Muromachi era (14th to 16th century) |
| Certificate 鑑定書 | 保存刀剣鑑定書(NBTHK HOZON TŌKEN Certificate) |
| Registration 登録 | 昭和47年6月17日 群馬県登録 Registered on June 17, 1972 in Gunma Prefecture |
| Included 附属 | 銀台金着二重はばき(Silver Base with Double Gold-Plated Habaki) |
| 白鞘 (Shirasaya Case) | |










