Question on "Microserrations"

I was always taught that when sharpening a knife it was desirable to have microserrations - little "teeth" left from the stone. That it was these teeth that did the cutting. Reading the old barbor texts in the SRP library I see that they reference these serrations also.

When I look at some of the microscopic images posted here I see that some razors are sharpened to a mirror like finish, perfectly smooth. Do these super smooth edges work as well as the ones with teeth?

This got me thinking. Has anyone video taped a hair being cut under magnification? Can we see what really occurs when the razor hits the hair? I imagine that there are lots of conflicting opinions about whether a razor should be perfectly smooth or whether is should have serrations, and it would be interesting to see what is actually occurring.

Randy

Even when razors have a mirror finish, there are still microserrations. They are just very, very small. The serrations on a knife are huge in comparison.

Also, with a knife, a lot of common tasks require the serrations to act like little teeth on a saw (think cutting through rope). However, with a razor, we are going for a push cut, no "sawing", just the blade slicing through the hair.

I'm sure someone else will chime in with some better explainations...

Yes this has come up before. All properly honed razor have these little teeth. In order to see them you would probably need a microscope with at least 500x magnification, maybe much more. We have had some heated debates on this subject in the past maybe it will all start over again.

I don't believe that any edge can be "perfectly smooth". Since the edge on a razor, knife or any sharp tool is produced by tiny, harder than steel particles within a honeing stone grinding away metal, serrations are a natural consequence of this process. The particles would have to be infinitesmally small to produce a perfectly smooth edge, but infinitesimally small things only exist in the world of mathematics!