Hand Tools Archive
With the chisels I've been testing, they started with a 30 degree bevel, so that's what I've been using before buffing the chisel. But it makes sense that a significantly lower bevel angle should work fine with the unicorn profile.
At least for the Buck Brothers chisel, the edge damage from chopping maple was within approximately .002" of the edge. This is the flat-honed condition, of course; when it was buffed, the chisel had no visible damage. If a chisel with a 25-degree bevel ends up with a similar profile very near the when buffed, then it seems likely that it will also stand up just fine to chopping, but also move through the wood with less resistance from wedging. That's an exciting possibility: a sharper, much longer lasting, faster and cheaper and easier-to-sharpen edge, which also cuts with less resistance from wedging.
I have a pair of Japanese paring chisels that I got about ten years ago which were sharpened to 20 degrees. They chipped like crazy, though, and I always wondered if was doing something wrong. I gave up on using them and they've been sitting in a closet, but maybe I'll try buffing them to see if there's a significant improvement.
Just speculating: it's possible that a much harder and chip-prone steel would still be chippy even with the buffed bevel. But with the edge durability that I've observed, there's much less of a need for really hard steel in a chisel. Maybe I'll even take a cheap chisel, grind it down to 20 degrees, and see how it holds up.