Allen wrench...

Allen wrench...  The photo at right shows the end of a 4mm Allen wrench at 60x.  The side to the right of center is visibly deformed, as is the center peak. 

I threw this under the microscope because I could feel the deformation, but not really see it with my naked eye.  It surprised me that I apparently had more “resolution” with my fingertips than with my eyeball...