Descent accumulation video of a "production run" Japanese Chisel...Thanks for sharing that!!!
They left out the tempering and many of the traditional methods of making them, probably because most of the makers are very guarded about what goes into their chisels...For example, the video show the "hollow" (I'm rusting on my Japanese for Bladsmithing) being ground into the belly of the chisel where the better made ones are done with a steel "draw knife" like tool called a "Sen." They would never grind a hollow in the tool as this distorts the "white" or "blue" crystalline alloy they use in that region of the tool. They forge the general shape (or many do) and then "Sen" the final shape into the tool...
They are simply the best chisels (over all) I have ever owned or used...but they can be "finicky!!!" as some shatter more like glass than metal if you have an accident dropping one or they simply crack and shatter on the belly side if you ever dream of "prying" out a chip...especially with the "white steels."
Thanks again for posting!!!!