Thread: How sharp do you like it?

Originally Posted by TonyFranciozi

...Sharpness has be defined as two surfaces meeting at a line of zero width. Such an edge is not possible (with today's technology) but hypothetically, it stands to reason that if those two surfaces are not smooth the edge they create will not have zero width, and thus will not be truly sharp...

Could the edge not have near zero width, yet not be a straight edge? That is, the edge comes together very closely (near zero width) yet it is a ragged edge that comes together with near zero width? Just thinking aloud; not arguing at all

Glen, can you expand on your last post a little? What happens if you 'take the edge too far? Will it become fragile and break?

Originally Posted by carlmaloschneider

Could the edge not have near zero width, yet not be a straight edge? That is, the edge comes together very closely (near zero width) yet it is a ragged edge that comes together with near zero width?

That's a good question, and I really don't know the answer. That's the hardest thing about sharpening for a beginner I think, not being able to see your work. At least not the last micron that matters.

Originally Posted by carlmaloschneider

Could the edge not have near zero width, yet not be a straight edge? That is, the edge comes together very closely (near zero width) yet it is a ragged edge that comes together with near zero width? Just thinking aloud; not arguing at all

Glen, can you expand on your last post a little? What happens if you 'take the edge too far? Will it become fragile and break?

Why you just figured it out for yourself

There are three aspects to the edge 1. Smoothness of the bevels 2. The sharpness, which is defined as the absolute micron width of the edge (about .38 microns "max" per the Verhoeven papers) 3. the "Eveness" of that edge from heel to toe (what we often refer to as jaggedness)

Each razor has a absolute max sharpen point by geometry and steel combined with the hones and the pressure (the honer)
When that point is pushed past then the edge fails, how it fails is determined by the razor itself and the honing... Most of the time it is a Harsh, Fragile, Chippy, edge, to learn this for yourself, push the edge and see what happens and how it feels...

On a practical level what I am trying to say is this: If you hone an edge at 240 grit, the sides will be rough, and the edge will be quite wide. At 1000 grit the sides will be smoother and the edge will be narrower, but still not nearly as smooth and as narrow as they would be at 4000 or 8000 grit. What I am saying is that sharpness (the width of the edge) and smoothness (of the planes that form the edge) progress linearly, and in tandem.

In the above example I'm assuming the blade is being honed properly. I mean, you could polish a butter knife on crox and it would be very smooth and shiny but still wouldn't be sharp because the edge is round. That is something completely different.

Originally Posted by TonyFranciozi

On a practical level what I am trying to say is this: If you hone an edge at 240 grit, the sides will be rough, and the edge will be quite wide. At 1000 grit the sides will be smoother and the edge will be narrower, but still not nearly as smooth and as narrow as they would be at 4000 or 8000 grit. What I am saying is that sharpness (the width of the edge) and smoothness (of the planes that form the edge) progress linearly, and in tandem.

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There is the flaw in your hypothesis, on a practical level, using your words, the edge gets sharp at a much lower level and much faster then it gets smooth...
Sharp is easy, search out the thread where the guys did a 1k bevel shaving test, sharp is there really early

Originally Posted by gssixgun

Sharp is easy, search out the thread where the guys did a 1k bevel shaving test, sharp is there really early

1k might give you a shave but that doesn't mean the cutting edge is as thin as it is after 8k. How could it be?

Originally Posted by TonyFranciozi

1k might give you a shave but that doesn't mean the cutting edge is as thin as it is after 8k. How could it be?

You are jumping to a conclusion,,, Try it and see what you find


If I were better at those cool computer graphics things I could make it more clear but alas I am not, Try and visualize that edge in 3d

Originally Posted by gssixgun

Try and visualize that edge in 3d

Hmmm . . . still not convinced hahaha.

It's times like this I wish I had an electron microscope.