Aizu Shintogo Kunimitsu Tanto Kata

A kata is a pattern or form used for study or reference when creating an utsushi blade. The exercise of accurately making kata based on the work of historical smiths is an excellent way to train the eyes, mind, and body to create proper forms. This particular kata is based on a beautiful tanto made by Shintogo Kunimitsu, known as Aizu Shintogo. He created the Midare Shintogo, the first blade in the Soshu-den (Sagami) tradition, is known as one of the best swordsmiths to have ever lived and a master of the tanto. He did his work in the late 13th century (Kamakura) and is acknowledged as master to Masamune, one of the most famous swordsmiths in Japan. Kunimitsu is recognized for his beautiful tanto and a careful study of his work is a great foundation for designs that are aesthetically pleasing and authentic.

I admire Kunimitsu for his fusion style approach to swordsmithing. Though there is some ambiguity surrounding the exact details of the story, it is held that, taking his foundation from the Awataguchi School of Kyoto where he studied, Kunimitsu relocated, developed his own style, and was one of the founders of the Soshu tradition. Another interesting thread for me is the connection between Kunimitsu and Munechika via the Yamashiro style.

Making a kata is not as difficult as making an actual blade for several reasons. One is that the outline is the only concern as the bevels are not created for kata. Another is that the raw material need not be as thick as it would for a tanto, 1.5mm is enough. And the final reason is that there is no tempering involved as the steel need only be mild and not high carbon. The most important aspect of making kata is to be very accurate and as true to the original lines as possible.

The primary difficulty can be finding patterns that have measurements so they can be enlarged to the actual size. Books with quality oshigata are one place to start from. I obtained this pattern from the soulsmith Pierre, he has a growing collection of scaled patterns available for download in his resource area as well as precision cut kata available for study. He also has more information on scaling and making kata.

I have had this particular pattern on file for several years and have continually had the printed image visible at my desk for pondering. I finally had the opportunity to make it into a kata a few weeks ago when I was working on another project and the steel turned out to be the wrong dimension and folded over as it was forged. Rather than waste it I decided to turn it into a kata while it was in the fire. Unfortunately I did not have the pattern with me at the workshop so I had to forge as near I could by memory, knowing the approximate blade length and width at the machi.

My initial attempt was quite close and only required a bit of filing to clean up the blade, proof that careful study of good examples can be internalized to a great degree. I had left the tang half forged for fear of taking too much of the blade away and finished it on the next trip to the workshop. I plan to use this kata for a project in the near future, in the meantime I am glad to finally have a physical kata to study and ponder.

Specifications of the Original Tanto

Shintōgo Kunimitsu (Meibutsu: Aizu Shintōgo), Kokuho (National Treasure)
新藤五國光 (名物会津新藤五), 国宝
Famously owned (and honourably used) by Gamō Ujisato, Sometime Lord of Aizu

Nagasa: 8 Sun 4 Bu (253.7mm)
Motohaba: 9 Bu (27.3mm)
Motokasane: 2 Bu 4 Rin (7.3mm) – worn
Nakago: 3 Sun 6 Bu (108.7mm)

Construction: hira-zukuri, mitsu-mune
Sori: straight/slight uchizori
Steel Appearance: Itame, mokume mixed with strong ji-nie and chikei
Hamon: Chu-suguha in ko-nie, ko-maru sagari, long kaeri, slight hakikake ?
Nakago: Ubu, one mekugi-ana, signed near the middle
Mei: Kunimitsu (another fine example | info about his steel | more examples of his work | info on the soshu school)

Island Blacksmith: Hand forged tanto kata
The results of forging to memory on day 1, with the actual pattern traced in black.
Island Blacksmith: Hand forged tanto kata
Overlaid, the main issue was the curve of the tip, with a little excess in the spine behind the tip.
Island Blacksmith: Hand forged tanto kata
Close up of the areas needing filing on the tip. Spending the time to get this as accurate as possible is important as this kata will be your influence as you work, long after the original paper pattern is gone.
Island Blacksmith: Hand forged tanto kata
I wasn’t as confident of the tang so I held off forging and shaping until I could use the pattern.
Island Blacksmith: Hand forged tanto kata
Day 2, ready to file the excess away.
Island Blacksmith: Hand forged tanto kata
Finished tanto kata next to the paper pattern, thanks for introducing me to this smith’s work and for providing the beautiful kata lines, Pierre!
Island Blacksmith: Hand forged tanto kata
A line study in steel, its actually far easier to make accurate subtle adjustments in steel than in paper, so cut carefully!
Island Blacksmith: Hand forged tanto kata
For comparison, here is the full sized tanto kata next to very small kotanto blade. You can see where this kata study has positively influenced the form of the smaller work.
Island Blacksmith: Hand forged shear steel tanto
A reasonable utsushi rendering forged from century-old-carriage spring shear steel, made using only a hammer and file, shown before yaki-ire so it has more gyaku-sori than the final blade.
Island Blacksmith: Hand forged tanto kata
The original, made in the late 13th century. (page 108, The Japanese Sword, Kanzan Sato, isbn 0870115626)

more about making tanto kata

3.03022 cm
= 0.1 shaku(尺)
= 1 sun(寸)
= 10 bu(分)
= 100 rin(厘)