Micrograph

Metal Micrograph

The Thermal Spray Guy has a couple of Struers Abramin Polishers for sale. Okay, but what is a Struers Abramin and why do you want to polish it? Struers is the company and they make equipment for examining the microscopic structure of metals. Found the above image on their website. I suspect the actual size of the section shown is about .005" (five thousandths of an inch).

Preparation of a sample for examination takes several steps of grinding and polishing with ever finer grit. They end with grit with a particle size of 500 nanometers. A line drawn on the above sample would hold one hundred thousand of such particles.

Struers has bunch of videos posted on YouTube.