Kakuuchi-Oire-Nomi Japanese Hand Made Bench Chisel By Ichihiro Ⅱ - 30mm

Smith name: Yamazaki Isamu (1912 ～1987)

Steel: White Steel No.1

Blade width: 30mm

Blade thickness: Blade Bottom(about 7.75mm)， The blade near the bevel（about 5.00mm）

Manufacture Era: Before 1963

Blade Cross section: Rectangular Kakuuchi style

Weight: 151g

Blade Angles: 25°

Total length: 202mm

Neck length:  45mm

Blade length: 48mm

Types of wooden handles：Japanese red oak (Akakashi)

Accessories：—

Additional Information: Used, in good condition. I did a repair sharpening, bevel to 1000 grit, ura to 1000 grit. This is an Oire chisel from the era of the second-generation Ichihiro. 

Based on the feedback from the steel and the condition of the burr while sharpening the chisel, the steel is quite hard—harder than the steel found in Kiyotada chisels. That said, the heat treatment is excellent, with a uniform microstructure and good toughness. However, since the toughness is slightly lower than most Kiyotada chisels, you might need to increase the bevel angle when working with hardwoods.

I also verified with Mr. Tsuchida that Kiyotada chisels generally use White Steel No. 2 (Shirogami #2), while Ichihiro primarily uses White Steel No. 1 (Shirogami #1). Speaking strictly of the steel itself—excluding the influence of the blacksmith's technique—White Paper No. 1 is harder, while White Paper No. 2 possesses greater toughness.