Rereading my second post, I think I came across a bit arrogant, I would like to apologize for that and will try and make up for it.
The answer to your question depends a bit on how you want to look at it. First, of course an ELU (End Line User) can put a sharper edge on a knife then it comes from the factory as long as he/she has the means to do so. All you need really is patients and a set of abrasives with different grit. In the factory the knifes are sharpened by the hundreds, each knife taking maybe a couple of minutes at most, while I (an I am sure some others as well) see sharpening a bit as a hobby and have spend an hour easily on a single knife experimenting around, trying to get the sharpest edge.
Secondly, a factory knife comes with a specific edge geometry and generally the modern steels are good enough to support a much thinner and hence a potentially sharper geometry. The factory does that, because they have to take into account the abuse a knife sees by the average bozo. If used within its intended purpose (kitchen knife only in the kitchen, and not to dig in the garden like my mother does
) a thinner geometry can actually outlast a more obtuse geometry.In general with enough care pretty much any steel can be sharpened well, but there are differences. Due to the microstructure of the steel, the steel will have different properties. Some steels are fairly coarse grained and are limited in their ultimate sharpness. One shouldn't misunderstand that though. Even those coarser grained steels can be sharpened to a point were they will embarrass 99% of all factory edges. But finer grained steels, especially some HC and tool steels do take an edge with higher ultimate sharpness. Furthermore, some steels have a higher edgestability, meaning they can be thinned out more than others (thinned out means they are sharpened at a smaller included angle). If you thin beyond the angle that a specific steel is capable of taking, the edge will either roll (bend over) or chip (small pieces of the edge breaking out) at the slightest use, or might even do so while still sharpening.
Finally, to me the most important distinction is burr formation. During sharpening a burr of varying size is always forming. For a good edge this burr must be removed in the final step (and sometimes in between as well, but that is a different issue). Some steels burr badly and some steel burr very little. I have come to associate the amount of free (!) chromium with the size of the burr. Some steels feel like rubber on the stone, you know you have a burr, but just can't get rid off, it just flops back and forth and even if you take drastic steps and reduce the size you might still have a small, barely detectable burr, that limits the sharpness of the edge. I HATE those steels, even though they may grind very easily. Then there are others, that barely burr at all. I can sharpen those steels blindfolded. Probably my three favorite steels in that regard are some very pure carbon steels like Shirogami, some tool steels (haven't tried to many though) like A2 from BRKT, and ZDP-189, which behaves very similar to a HC steel. S30V and VG-10 sharpen very nicely for me as well in that regard. You asked for 8Cr13MoV in the other forum, it is also a steel, I think, works quite well on the stone.
Hope that helps.
