GB/T 18449.1-2009 Focused metal material Knoop hardness testing. Part 1 of the standard elaborates the test method, clarifies the test principle, and specifies the technical parameters and accuracy requirements of the equipment used. Detailed description of the sample prepative process, covering key links such as test force selection, loading time, measurement procedure, etc. With this standard specification, the Knoop Hardness of metal materials can be accurately determined, providing a reliable basis for hardness testing for metal material performance evaluation, quality control and processing process optimization.