Hello   This is something that I've been wondering about for a few weeks. I've seen different blades with different kasane , thinner about 4mm and thicker 6mm kasane with bohi,  does the depth of bohi vary with the different kasane? On my shinsakuto I've measured  there is only approx 1.1mm of metal between valleys either side when I checked with my vernier in the middle of the blade. This seems to be very thin , the sakikasane is about 5mm. Can anyone else give me any other measuremen