Learning more about ō-suriage mumei nihontō

[Sugiyama]

Hello, all! I last posted here roughly 10 years ago, with nearly no knowledge of nihontō or Japanese swordsmanship. I'm happy to say that in the last decade I've become involved in a koryū and now own two nihontō; one gendaitō by Akamatsu Tarō brothers Kanetsugu and Kanehiro, and as of two weeks ago a mumei ō-suriage blade.

I purchased this sword at the Chicago sword show, and was told it was likely a late kotō blade (the seller estimated around 1500, give or take). Regrettably, my knowledge of nihontō is still pretty sparse, so it was my hope that folks here may be able to give me their opinions on this sword's age, the style it was forged in, and any other details that can be surmised. Provided below are all the measurements I have taken of the blade, as well as photos and videos where I do my best to capture the jihada, hamon, and overall shape of the blade.

Omosa- 692g
Nagasa- 87.3cm (Edge- 68.3cm (2尺2寸5分))
POB (In mount, from tsuba)- 14cm

Sori- 1.1cm
Motohaba- 29mm
Motokasane/Shinogi- 5mm/6mm
Nakahaba- 26mm
Nakakasane/Shinogi- 4mm/5mm
Sakihaba- 19.5mm
Sakikasane/Shinogi- 3.5mm/4mm
Mekugi ana- 2, plus one partial

 

Link to the photos/videos of the blade: https://photos.app.goo.gl/a45Vn7ZJKukeCj1u8

 

Please feel free to request additional images or details if necessary!

I greatly appreciate anything that anyone can contribute. Thank you for your time _/\_

[Rivkin]

With this shape and boshi its Nanbokucho, late Muromachi or shinshinto. Nambokucho is probably out. Two other options are both valid without having a more detailed view. Nakago suggests its late Muromachi. Hamon is a bit more shinshinto. It does not seem to have glaring issues, but its not a high level blade either which makes a more detailed attribution difficult.

[Sugiyama]

39 minutes ago, Rivkin said:

With this shape and boshi its Nanbokucho, late Muromachi or shinshinto. Nambokucho is probably out. Two other options are both valid without having a more detailed view. Nakago suggests its late Muromachi. Hamon is a bit more shinshinto. It does not seem to have glaring issues, but its not a high level blade either which makes a more detailed attribution difficult.

What sorts of details can I try and capture that may shed more light? I did add some more picks of the hamachi, munemachi, and bōshi to the album, but they're in the "comments" area. 

 

Thank you for your insights so far! I didn't assume Nanbokucho due to the blade's narrow profile and relatively minimal curvature- I had read those blades tended to be much larger in breadth.

[Rivkin]

Yes, it would typically be wider and retain some curvature. I think the main problem with going further is that post-mid-Muromachi unless it is a top level blade you can't really kantei it precisely.

[Rivkin]

But the basic problem of 99% photographs people post here they are taken in the sun during the day with light from above.

It needs to be one lamp on a side no other sources of light.

With this there is a chance to get what it is. As of now its probably 1570-1600 blade.

[Sugiyama]

Added a video that I hope better displays the hada at very least 👍 Having a bear of a time getting these photos just right...

[Rivkin]

Yes, its very hard and still much is missing, but just doing a bit of a banter: Mino, end of Muromachi.

[Sugiyama]

Redid all the photos, hopefully more useful. Once I got a better light source (neglected my living room lamp) I got much better photos.

 

Thank you so much for looking and for all your help!

[Rivkin]

I think its good as is. Mino, late Muromachi.

[dimitri]

I couldn't send you this photo.

Dimitri