David and Carl, the Blade Steel FAQ by Joe Talmedge puts 12C27M into the same rough category as Buck's 420HC, assuming a good heat treat. Is that consistent with your experience with the (newer) Opinel INOX?
Regarding Stan's comment that "geometry cuts", can anybody give examples of times where hollow grinds consistently out perform others? Meat processing?
One thing that Sandvik has going for it, that might give some additional advantage, is their process for producing the steel. Sandvik has a reputation for the purity of their steels, and their process is also known to produce very fine grain. Finer grain usually translates to finer edges, and also to increased toughness as well. In terms of the basic chemistry, they do look very similar though.
One thing sort of unique about 420HC, in my mind, is it's very predictable tendency to form burrs & wires. Not such a big deal, it's fixable; and they're more easily cleaned up on Buck's blades (higher RC) than on Case knives. But, I haven't noticed nearly as much of the burr-forming tendency in the 12C27M blades on Opinels. Maybe it has something to do with differences in size and/or even distribution of the chromium carbides (maybe finer in Sandvik's), or maybe not. I don't know, but Sandvik's manufacturing process is probably more advanced, based on reputation anyway.
Regarding hollow grinds, I've come to like them a lot for food prep. Does work well for slicing meat, and I've also noticed a peculiar advantage in slicing some fruits, like apples. Apples are kinda weird, in how they can make some blade profiles really bind up in slicing them. This has bugged me with my Opinel which, for some reason, the thin convex can really 'stick' inside the apple, which seems to grip the blade in almost a vise-like manner. A hollow grind opens up a little space between blade and fruit, so the 'vacuum' effect can't make the blade stick like it often does with flat grinds or thin convexes (like Opinel).
David
