Ask ferret.(see the management)

Chris Williams

Q:Is there some simple, inexpensive way to measure the sharpness of a cutting edge, such as on a drill bit, lathe bit or end mill, to help predict when sharpening is needed?

From my experience as a fitter and turner we used to run the sharp edge over our fingernail. If it scrapped the nail and removed some of it was deemed to be sharp. If no nail was removed then it was blunt. Alternatively we have a 21st century method which is to use our digital microscope at 50 times magnification. This will not only magnify the image on a PC screen, but in