Japanese Chisel Question

[Wilbur Pan]

I get it. Just wondering what this does to the edge. I mean, it’s plastically deforming. I would think it work hardens it and may leave residual stress. I get that the bevel side is soft. But the back is hardened, sometimes very hard.

Also curious about why Japanese craftsmen would do it? I suspect it was a faster way to sharpen when good coarse abrasives weren't available.  Now that they are, is this an obsolete technique? I think the hollow ground feature is a cool idea. I just think I would sooner hone it out, as that’s better for the edge. Tapping seems both risky and potentially damaging.

Last: the fact that Japanese craftsmen have been doing this for a long time tells me whatever damage is done to the edge is probably minor/imperceptible. One thing I’ve learned studying and recreating old woodworking is that our ancestors were smart and practical.

I think this is one of those examples of what Yogi Berra was referring to: "In theory, there's no difference between theory and practice. In practice, there is." 


I'll mention this again, as it goes along with your last comment: the tapping out process is a lot easier than it seems. I know that before I tried tapping out, it seemed like a task that I could never master. After the first time I tried it, I realized that it was much easier than I thought it would be.

I suspect you've had the experience of trying to talk someone into trying hand cut dovetails for the first time, and after they try it, they realize that their trepidation was really not warranted. Same thing here.