Quote Originally Posted by straightman View Post
...I have a theory. Help me with this. My theory is the hanging hair is cut when there are microscopic "teeth" or a very sharp but rough surface on a blade (something to "grab" it), but will not be cut when there is a sharp but smooth surface. And that is why you can still get a good shave even though a razor does not pass the HHT. Am I right on this or full of sh8# ? Thanks for your comments.

Tom
I have tried the HHT with my hair with razors received fresh from all the best honesmen I know, and I've never been able to do it.

Now, your theory. Every edge has microscopic teeth. Unless there's a limit created by the crystalline structure of steel, I would expect the teeth to get finer as the edge gets sharper. So, an edge that does NOT pass the HHT would have larger teeth than one that does. In other words, the effect is opposite to what you're proposing- smaller teeth pass the HHT.

I don't know what would happen with a perfectly smooth edge, because I don't think it exists. But if you called an edge produced by a 15K hone smooth and one produced by a 4K hone as toothy, the smooth edge would pass the HHT.