The first impression of Viel S-5-M

[SHARPCO]

50-70.  Very impressive Mr. Sharpco.

One thing that has caught me up a number of times is that when using leather for deburring it's easy to burnish or smear burr material into a deceptively super sharp edge.  While it can get extremely sharp, it is also very weak and rolls and crushes under minimal stress.  Microscopic examination is informative in that regard.

You're right grepper. I need USB microscope.