Where do knife steels come from?

[me2]

The hardness range would be similar, however I don't think you'd see very many cutting tools with just sintered blades. The process, at least for cutting tools, starts with sintering of metal powder, and is followed by hot rolling. The hot rolling is necessary to get shapes convenient to make cutting tools (sheets instead of 5" thick billets), and to remove any small bit of remaining porosity that might be left over. The goal is to sinter to 100% density (no porosity remaining), but hot rolling ensures it even more. The spaces between the particles are already quite small, but with edges on the order of 1 micron, even tiny pores could have detrimental effects.

The difficulty in sharpening comes from the high volume of very hard carbides generally found in CPM/powder type steels. The carbides are often harder than the common abrasives used. Vanadium carbide is harder than the aluminum oxide used in common sharpening stones, and about the same hardness or a bit harder than the Silicon Carbide used in common stones and wet/dry sand paper. These other stones can be used to sharpen, but require more care, knowledge, and skill. Diamond can be used, but a fair amount of care is still needed, and even with diamond, it takes longer than normal. I have a blade in S110V that frustrates me to no end, as I'm not able to get it as sharp as my other blades, even with diamond stones down to 1200 grit (DMT Green Extra Fine). S110V has a fair portion of very hard vanadium carbides.