Hira-ganna Japanese Smoothing Plane with Thin & Extended Blade - 65mm

Blade Angles: 23°

Blade thickness: Blade Bottom(about 8.0mm)，Top of Blade（about 4.3mm）

Dai manufacture: Unknown

Manufacture Era: Before 1960s

Dai size(length, width, thickness): 257mm 78mm 35mm

Weight: 934g

Additional Information: Used. I purchased it from a descendant of a retired carpenter. Although the wooden body has warping and some cracks (end faces), and the chip breaker has rust, I am impressed by the precision of the blade. 

The blade is thin, but it is not a thin blade formed by grinding machine processing, but is obtained through precise forging. Steel and iron lamination is evenly produced without imbalance. The top surface of the blade is made using a hand file, not a flat surface machined by a grinder.

The steel behaved great when I sharpened it. The burrs I got when sharpening connected into very thin "steel" threads. I have only experienced this when sharpening a kiyotada chisel. This shows that the carbide of the steel of this blade is very uniform and is most likely carbon steel similar to white steel.

For more information about thin plane blades, please refer to my blog: 「The evolution of the Japanese plane blade "Nikuoki" since the end of the Edo period」