This knife is #1 of #15.
Here is the process of how the yanagiba was finished after purchased from Shosui Takeda.
- Blades were 7-7.5mm thick near the matchi and 5mm thick at the center of the blade before they were thinned. This took almost 6 hrs for both knives.
- The edge geometry/profile was uneven and over ground on both knives thus was repaired by both the sharpener in Sakai and Ivan Fonseca at the time of the final sharpening.
- 3mm was taken off the depth of the knife to correct the edge profile problem.
- The entire knife was re-ground:
Hira, kiriha and ura as well as the spine
(The ura on both knives is really perfect!)
- final sharpening by Ivan (Tosho) was done on these stones:
120, 320, 400, 800, 1k, Aoto, old stock shoubudani, ohira suita vintage, okudo and old stock Uchigomori
1k, Aoto, shoubudani old stock, Nakayama Karasu
This finish is not supposed to be mirror finish on the hard steel but a misty look.
The HRC is around 64.
Note, you can see the way Takeda does the soft steel is very different from how it's done by blacksmith in Sakai. That's why you don't see it wrapped around on the back near the matchi.
Anyway hope this helps you understand the finish of the blade.