Description: Material: This is a Hardness Tester File Set are made of quality metal, providing durability and longevity. The set includes six files, each measuring 175mm in length.Color Coded Hardness Range: Each file represents a different hardness range, indicated by its color - Red (HRC40-42 HV392-412), Yellow (HRC45-47 HV446-471), Yellow Green (HRC50-52 HV513-544), Green (HRC55-57 HV595-633), Blue (HRC60-62 HV697-746) and Black (HRC64-66 HV800-865). This color coding system makes it easy to identify the hardness range.Ergonomic Design: The files feature an anti slip grip for comfortable handling and can be used across a wide hardness range from HRC40 to HRC67. The curved head of the file is designed to handle various shapes including flat surfaces, convex curves, and concave curves.Versatile Use: These files are ideal for removing rust from test materials in advance They leave marks on objects softer than the file's hardness when pressed and rubbed against them. They can be used on large workpieces or special steel outdoors where testing machines cannot be placed.Package Contents: The package includes six files of different colors representing different hardness ranges, all packed in a black box for easy storage and carrying. Size Chart: 17.5cm/6.89inch Package Includes: 6 Piece Hardness Tester File Set Note: Please allow slightly errors 1-2cm differences due to manual measurement.