Kanna Japanese Smoothing Plane Blade By Chiyotsuru Nobekuni - 75mm

Blade Weight: 339g

Blade Angles: 23°

Blade thickness: Blade Bottom(about 9.0mm)，Top of Blade（about 6.1mm）

Accessories: -

Manufacture Era: Around 1950

Additional Information: Used, This blade is not recommended for beginners. It comes from the descendants of retired carpenters in the Tokyo area. 

After Mr. Ochiai Yuichi retired in 1973, most of the third-generation Chiyozuru planes are made by Ochiai Uichi's sons, Ochiai Giichi (落合義一，the eldest son) and Ochiai Kazuyoshi (落合和吉，the second son). After 1987, Yoshiichi's health deteriorated and Kazuyoshi was the only one who continued to work in the blacksmith shop. Therefore, most of the third-generation Chiyozuru plane currently on the market are made by Ochiai Kazuyoshi.

I asked Mr. Tsuchida Noboru to authenticate this blade, and he told me it was the work of Mr. Ochiai Yuichi. Mr. Ochiai Yuichi officially inherited "Chizuru" from Chizuru Korehide in November 1947. This blade was probably made around 1950.

This blade has some unusual markings.
1: The "上" character on the left side of the second image. "上" has many meanings, such as "upper" in terms of direction or "higher" in terms of rank. 

2: The "half circle on the horizontal line" postmark is on the left side of the third picture. This postmark is relatively small, please enlarge the picture. Unfortunately, I asked Mr. Tsuchida Noboru, but he also didn't know the specific meaning of these marks.