Quote Originally Posted by khaos View Post
I will say I noticed this "crushing" thing on my awase-toishi- after lapping its rougher than after many uses without lapping. So now I don't really lap it.
I was talking about working the mud on a stone... the mud or slurry will become finer as honing progresses... I.e. you start honing on an 8K Kitayama stone, work up a slurry and then polish on the mud, the particles in the mud will break down and give you a 12k finish... though perhaps people don't build up a slurry for razor honing?

How many sintered hones will all the grains be within a certain tolerance, unless they are manufactured? And if they were cost effective, surely they would be manufactured more often than the case 3 hones? I think we are largely in agreement though.
Oh, nature can produce some pretty homogenious textures via sedimentation or partial crystalization. I mean they might vary quite a bit over an area of several acres, but be pretty much the same over the space of a few cm or meters. Oh, sintered hones are... nearly every western sharpening stone from a hardware store (common oil stone) is a hard sintered SiC or Al2O3 block. Crock sticks would also fall into that category as do machinist's ruby stones.

I have also noticed "finishers that just match..." but that's a whole other story. I once suspected it has something to do with the type of steel matching the crystalline structure of the abrasives in such a way that they can cancel to a "flat/straight" edge. This thread isn't totally accurate or fully thought through but you might like it: http://straightrazorpalace.com/basic...r-musings.html
Interesting. Not sure where fourier analysis would go with this... even harmonics produce triangle waves and odd harmonics produce square waves... doubling the grit halves the particle diameter, and the grooves left by the particles would probably be D wide and 1/2 D deep unless the abrasive is used with too light a pressure to sink it in very far (more likely with round crystals like garnets would produce shallower scratches due to the ~120 degree angles on the vertices requiring more pressure to sink them halfway into a steel surface than sharp angular xtals like diamond).

Since, unlike knives, razors are mainly stropped on the surface of a hone using the weight of the razor, it is likely that even sharp abrasives probably do not embed much beyond the tips (though particle density per unit area would be lower so each cyrstal would ge more pressure and tend to sink in more than a smaller grit would... up to a point anyway), and at that point Utopian's idea of grinding off the tips of the peaks begins to make more sense (probably also if there is a large a skip in grit size). The pyramid honing probably also helps dislodge bits of burr or work/flow fatigued steel from the edge.

Unlike SEMs, depth of field in a light microscope is rediculously shallow, but here is a pic I did of the edge of a fresh Xacto blade...


pretty wavy there. I'm more into chip carving knives and wood and I've never done a microscopic analysis of the dynamics of various tooth shapes on the sawing, or slicing, of hair but people complain that diamond makes a razor too sharp and grabby, so maybe it makes a very fine but toothy edge that acts like a saw, while coticule makes a more gently curved scallops that are not quite so agressive at biting into hairs and thus don't pull as much?

A lot of variables to look at there, though maybe getting out some clay and experimenting with some cardboard rakes could simplify things (did you see the neat photos of sidewalk chalk another user posted?... they look a lot like what I see under my microscope so maybe chalk and various rough surfaces would also make a good model!)