Vintage Japanese 70mm kanna.
This kanna blade is marked in hand engraved kanji down the middle YOSHIYASU, and to the right NYUDO and over on the left TAMAHAGANE.
The traditional laminated kanna main blade was made in about 1949 by Ishiguro Keijiro of Yoita, Niigata.
This is a white paper Hitachi high carbon steel and kamaji wrought iron laminated blade, hand forged in the traditional manner. It has not been used and there are no folded edges or hammer marks. There is a patch of rust that has pitted the blade that you can see in the photos and although many years away, at some point in the future the inner most area of this oxidized patch will affect the cutting edge. This rust is the result of the blade being stored in the dai over a long period of time.
The blade is marked Tamahagane but Mr. Ishiguro told me that as blacksmiths have a certain amount of poetical license in naming their blades they will also evoke the name tamahagane to mean "the finest steel in the style of tamahagane" meaning white steel usually of domestic origin and almost always Hitachi. Also the blade is marked Nyudo and like with many Japanese words there are at least a couple possible uses. Nyudo can refer to the Buddhist practices of entering into a higher state, or simply shaving your head. Also Japan's greatest swordsmith was named Goro Nyudo Masamune who was active around 1288-1328.
This is a really lovely blade with its hand engraved kanji and finely pebbled surface. The hagane, hard steel has an attractive and tight weld line and the jigane, soft iron has all the attributes of kamaji antique wrought iron with its multitude of folds and impurities.
The sub-blade does not have the special kamaji soft iron but it is laminated with hard high carbon tool steel giving it the springing action that helps to cut down on chatter in difficult woods.
This kanna was made for the Japanese professional woodworkers market, not for export. In Japan up until the 1970's, general handymen or homeowners did not normally buy specialized 70mm finishing planes of this quality. They were expensive, required training to maintain and would not likely be used often enough . This is an example of NEW/OLD stock that has not been used but has instead just been languishing as dead storage since the 1960s in a closed up store in rural Japan until I brought it to the U.S. along with many others about four years ago.
The white oak dai, judging from the osae boh or chipbreaker retaining pin, was probably made in the 1960's, it is bone dry and I and have partially fitted the main blade down the blade chute hand tight to within 2.1cm of the sole and mallet tight to within 1.5cm of the sole. This is a dense and beautiful high class oimasame or quarter sawn grain pattern dai with the blade mortise set up with the tsutsumi-guchi ledge to support the blade bevel when the plane is set up in the cutting position. The tsutsumi feature is found in better dai and requires extra steps in the making. This style provides a very narrow mouth at the sole of about 3.5mm wide, necessary for really close finish planing.