Universal hardness tester - video

[mansworld]

There is an easy and quick tool used to approximate hardness in Rockwell scale. A set of Japanese made 6 color coded files ranging 40/45/50/55/60/65 HRC. Slide the test file across the surface to be tested one by one, starting from the hardest file (black-65), if it marks the surface, the hardness of the material is less than 65 HRC. Then proceed to the next file (blue-60), if it does not mark the material then the hardness must be between 60 and 65 HRC. If it does mark the material, then proceed to the next file (green-55), and so forth.