Our 58mm Tesshinsai Smoothing Plane is made by Yoshihiro Yamamoto using special high carbon #1 blue steel (Aogami Hagane) which is hand forged multiple times creating microscopic particles evenly distributed throughout the steel. This process gives a very sharp, long lasting edge. The steel is then forging inlaid on to a piece of soft wrought iron made more than 150 years ago. Mr. Yamamoto then heat treat and harden the blade to RC 66. Finally it is sharpened to a razor edge and installed in a Japanese White Oak Body at 45° for planning North American hardwoods. Blade width is 2-3/8˝. Body width is 3;˝ and body length is 10½˝.