Thread: Smooth Vs. Sharp

Originally Posted by Jimbo

Where I differ a bit from the conventional way of thinking is that I tend to think you can keep making the edge finer (sharper) as you move up the grits. I definitely do not subscribe to the idea that what you have after the 1 or 4K hone is the best you'll get in terms of how closely you can make those sides meet. As long as you are abrading, no matter how slowly, you are moving those sides closer together. It might be negligible in comparison to what happens off a low grit hone, but it is happening.

So as a philosophical thing I do not tend to make a distinction between sharp and smooth, because to me going for sharp does not end once you go higher than a 4K hone. But that is just me and I certainly do not claim any monopoly on, nor mastery of, razor honing theory.

James.

I agree totally. I have long disagreed w/ the "sharpness ends @ 4k & all the rest is just smoothness" idea: if that were true, why is a S30k or Jnat finisher edge sharper (in terms of beard cutting ability) than one finished off a Norton or coticule? Why do the finer finished edges shave closer WTG than the 8k edges if the difference is really nothing but smoothness? Does a 1k or 4k edge shave beard hair effortlessly? Of course not, which is why we generally don't stop there.

Of course, as we smooth the bevel planes, cutting friction is reduced (the blade slides more freely through the hair shaft & acts sharper), but I do think that the bevel continues to get thinner as we go (maybe only very slightly, but still). Some softer steels have a reputation for not like the finish of say a S30k--"can't handle the sharp" is a phrase I've heard used many times. If these superfine hones did nothing but polish rather than refine, presumably that wouldn't be a factor, but it seems to be.

I personally think that a lot of what some people perceive as being the "smoothness" of an 8k & up (as opposed to shaving off of the 4k) is actually sharpness--the razor feels smooth because it cuts the hair effortlessly, rather than pulling slightly. Sort of a much milder version of a dull razor pulling, if you will.

An engineer would call you correct...

Numbers wise they fall out close to this

Hair cuts at about .50 microns, razor edges depending on the steel and grind max out between .37 Microns and .47 Microns.. You hit the .50 Micron at 1k level easily, by the time you get into the 4k level you have achieved near the max of the edge at the 8k level you are about at 99% of as good as that blade is ever going to get.. After that you are striving for that last 1%, of which 99% is probably all personal opinion anyway...

*all numbers come from the Voerhaven(sp*) papers, the percentages are mine, note that I said grit "levels" this has nothing to do with actual grit, it has to do with Bevel, Sharpen, Polish, and Finish levels of honing SR's*

So yes, you are by engineering standards, correct, that even with finishing you are still "sharpening" but you are really splitting hairs with that analogy (pun intended)

If somebody is trading off smooth vs. sharp in my book they don't know what they are doing.
Any given razor has a limit of the edge it can take. Beyond that the edge breaks down and it is not smooth at all. The goal of honing is to get as close to that limit as possible without crossing it.

An example would be a feather blade (the ones that go into the feather razors, not the DE ones which I have no experience with). These blades are as smooth and sharp as it goes. They also need nice and light touch, otherwise you'll be cutting the skin instead of the hairs.