[quote quote=“razoredgeknives” post=3562]So there is a thought out there among those of us who love the science behind the edge of a blade that says that the more refined you make an edge the thinner it becomes (i. E. If you were to use a metallograph and take a microscopic picture of the edge looking directly down on it). I don’t have the article here, but this has been done on a commercial razor and it measures around 4um if my memory serves me correctly. But I know that several people can attest to the fact that they can get hair whittling edges at relatively low grit… So what are your thoughts on this? Does the edge get thinner the more you refine it? Does that make it weaker for edc use?
I’ll try to find that article and post it soon… It’s an interesting read :-)[/quote]
I’m a little late in joining here, so I’ll jump back to the beginning 
Here’s my take:
Commercial razor blades, they get away with being less refined because they are very thin - around 0.3~0.5mm thick, which allows them to slice better. The usually have a more obtuse edge angle than you’d think - something around 23-25 degrees per side.
When using diamond plates (WEPS or otherwise) the diamonds literally score through the edge of the edge, actually leaving what can be considered a “negative” of sharp - the scored scratches are acting like scalloped serrations, while leaving a thinned down, but still relatively thick edge of the edge width rather than the edge of the edge being thin enough to sever cleanly. This is what I call a “false positive”, and why you can shave arm hairs off of a coarse diamond plate such as the DMT 325.
Once you switch to the ceramics, Choseras or Shaptons, the depth of the scratches begins to bring down “the rest” of the higher points - IOW, it begins to thin out the thickness left by the diamonds, which is whey there is a perceived loss of sharpness and the edge no longer necessarily cuts hairs. You will also initially see more micro chipping as you work out the deepest scratches.
Only when you cancel out the scratches from the previous grit (or bottom them out) do you begin to thin the width between the two planes of the bevel. Once you achieve a thin enough wide at the edge of the edge, you can sever or “pop” hairs with ease instead of sawing through them. Whittling implies a greater width of the cutting edge, either from lack of refinement and/or more obtuse geometry.
If you jump to the diamond pastes and other compounds, as we’ve seen in the past, they tend to “polish the grooves” more, leaving a very well defined, yet still rather serrated and thick profile. This leaves a more toothy edge that has its serrations thinned out, making it more aggressive, but with less finesse than a more consistently formed edge.
So the long answer is, if you sharpen like I do - to remove the previous scratches, the edge becomes thinner at each grit and therefore more fragile. You can reinforce that thinness with increased geometry, such as adding a microbevel. But if you sharpen to polish the grooves, then your edge doesn’t necessarily thin out as much, but you will lose that refinement quickly because it is really just a smaller scratch within a larger scratch, and that larger scratch is the “real” scratch, or tooth, if you will.
B)
