Kanna Japanese Smoothing Plane Blade By Chiyotsuru Nobekuni - 76mm

Blade Weight: 364g

Blade Angles: 24°

Blade thickness: The blade near the bevel(about 6.55mm)，Top of Blade（about 9.50mm）

Manufacture Era: Around 1950s

Accessories: -

Additional Information: This is a pre-owned plane blade sourced from a tool collector in the Tokyo area. There are two patches of relatively heavy rust on both sides of the blade—one larger, one smaller. However, as the blade wears down over time toward these areas, they fall well within the non-cutting ears (mimi) of the blade, so they will not affect its functionality.

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 had this blade authenticated by Mr. Noboru Tsuchida, who confirmed that it is indeed the work of Ochiai Yuichi. Yuichi officially inherited the "Chiyozuru" name from Chiyozuru Korehide in November 1947. This blade was forged around 1950.

There are a few unusual markings on this blade:

1: The character "上" (jō / top/superior) visible on the left side of the second photo. While "上" can indicate orientation ("upper") or denote superior quality/grade, Mr. Tsuchida offered a new perspective this time: it likely signifies a superior grade of jigane, quite possibly a type of watetsu (traditional Japanese iron).

2: The plum blossom mark, which indicates the use of White Steel (Shirogami).