Originally Posted by
fuzzychops
I couldn't agree more with Kyle. I wish my knives were as sharp as the dullest straight razor I have ever used.
There is a limit to how sharp a knife can be made; the maximum keenness is limited by the steel, the geometry, the hones... If we measured the edge width with an SEM, that limit is a fraction of a micron, maybe 200 or 300nm.
It turns out that a good straight razor edge needs to have an edge width of around 100nm and we produce this with a grit that is about ten times larger; a good finishing hone has a grit size around 1 micron (1000nm). So, I would argue that we want to produce an edge that is essentially sharper than the limit of (normal) sharpening. It can be done, but it require skill and experience. Of course you can scrape the whiskers off your face with that 200 or 300nm edge if you want.