Thread: Scanning electron microscopy and straights.

I put my razor in the SEM at work to see how sharp (or dull) it was. I stropped it, just like I would for a morning shave, just before putting the razor in for analysis. Check out the pics to see the results. The measuring scale on the pictures is calibrated correctly.

This is my H. Boker that I use every day and is a great shaver, but...


Here is the edge of the razor at 50x magnification. The edge is the darker shade of grey. It looks pretty defined and sharp at this magnification.


Here it is a little closer at 500x. Looks like I need to go back a few microns during the hone.


Finally here is the very edge of the blade at 2000x!


The radius of the edge is about 2-3 microns, which is pretty good; however, knowing that those grooves are there I can go back a few stages during the honing process and get rid of those grooves which will reduce the surface roughness and decrease the possibilities for pitting corrosion of the blade. Corrosion is what really makes the blade dull after all.

The overall condition of the Boker razor examined above can be seen here.


I found this to be the absolute best way to see how sharp my honing skills are. This lets me aspire to increase my honing skills and get an even closer shave.

-Ross

Holy Crap! 2000x.That's amazing.Thanks for posting it.

AHA! you're just the guy we need!

In case you haven't seen it yet, a Prof of Metallurgy at U of Iowa did a study with an EM a few years ago:

Experiments on Knife Sharpening

He went up to 10,000x though his paper only shows photos up to 3000x, and he also measured the edge thickness of a variety of blades (commercial, straight razor, and his own test edges), and used different hones and abrasive pastes. Turns out that commercial razors and straight razors are the same sharpness btw. His photos looked an awful lot like yours which is good - his results don't appear to be a one-off thing.

The problem is that he wasn't looking at razors specifically, so he didn't scan a razor post-shave, and didn't scan post-honeing vs post-stropping of a new edge (leather, linen) vs post-stropping after a shave.

There was a study done back in the early 30's looking at these issues, but they were using a 3000x optical microscope with all the concomitant problems.

You sir on the other hand would appear to be in a great position to rectify this situation, as well as resolve a great many long-standing debates on this forum as to exactly what if anything the various leather and canvas sides of the strop actually do and why razors get dull (or fail to get dull in the case of some members), and would receive the everlasting appreciation of your fellow shavers.

hint hint hint pretty please with a cherry on top...

A resounding Huzzah and another pretty please with a cherry on top.

Oh man....you are going to drive yourself NUTS with that thing!



I also have a SEM here at work too, but I get obssesive enough looking at my edges at 200x under a very nice optical scope....

So...I guess you don't really need the Marker Test

Those are great images. Thanks for sharing.

couple of quick follow-ups:

Did you strop on the canvas side or just the leather side?

What kind of canvas?

What kind of leather?

Originally Posted by rosscollins3

I put my razor in the SEM at work to see how sharp (or dull) it was. I stropped it, just like I would for a morning shave, just before putting the razor in for analysis. Check out the pics to see the results.

Do you mean this edge has just been honed on a stone and also stropped? What was the finishing hone?

Also, did you strop linen and leather sides or just leather? I see some very flakey burring on the edge in the 2k photo that I would expect the linen to have burnished off.

Guys..that is at 2000x that's a pretty close-up view of teeeny tiny imperfections!

Originally Posted by Bill S

So...I guess you don't really need the Marker Test