This standard specifies the test method for the Kirschner Hardness of colorless Optical inspection Glass, including test instruments, test steps and data processing. This part applies to the measurement of Kirschner Hardness of colorless Optical inspection Glass. Kirschner Hardness refers to the ability of a material to locally resist the pressing of hard objects into its surface, by using a diamond indenter of a specific shape to produce indentation on the surface of the sample, and calculate the Hardness value based on the length and projected area of the indentation. This standard provides specifications for the Hardness measurement of Optical inspection Glass, ensuring the accuracy and conformity of the test.