Set of six precision testing files with specially curved tips. These re designed to reach into bores, slots and grooves that cannot otherwise be tested with conventional types of hardness testers. Each file has a non-slip grip colour coded handle for hardness assessment, with the Rockwell value printed on each. Files range from HRC 40 through HRC 65. Set comes complete with instructions and conversion chart Rockwell C to Vickers. Provides a quick and inexpensive way of testing work piece hardness.