Description The TTC Hardness File Set provides an easy-to-use method for ascertaining material hardness, which can be determined by sliding the files across the surface of the material you are testing. The set includes six color coded files, which indicate hardness ranging from 40 to 65 HRC. As illustrated in the video, simply run the file across the surface of the object, starting with the hardest (65 HRC) file. If the file marks the surface, the material is less than 65 HRC. You would then proceed to the next hardest file (60 HRC) and repeat the process as needed until the hardness file is unable to mark the surface of he object you are testing. The approximate hardness of the material will be between the file that marks the surface and the most recent file to slide over the material without leaving a mark. Color File Hardness Material Hardness Indication Red 40-42 HRC 392-412 HV 40 HRC Yellow 45-47 HRC 446-471 HV 45 HRC Lime Green 50-52 HRC 513-544 HV 50 HRC Green 55-57 HRC 595-633 HV 55 HRC Blue 60-62 HRC 697-746 HV 60 HRC Black 64-66 HRC 800-865 HV 65 HRC
