Description
High quality Japanese made Hardness Test Files are an easy to use, quick and inexpensive tool used to approximate material hardness in Rockwell scale.
Usage is simple. Just slide the test files across the surface, one by one, starting from the hardest until reaching a file soft enough to not record a result. Based on reaching a non-result, the material must be harder than the file with no result and softer than the lowest file that gave a result.