This standard primarily specifies the method for determining the Leeb hardness of metallic materials using specific types of portable hardness testers. The core instrument of the standard is the Leeb hardness tester equipped with D, DC, S, E, D+15, DL, C, and G-type impact devices. Such hardness testers are typically compact and portable, calculating hardness values by measuring the rebound velocity of the impact body on the material surface, and supporting conversions between different hardness scales (e.g., HRC, HB, HV, etc.). The standard covers the test principle, requirements for instruments and specimens, test procedures, measurement uncertainty of results, and test reports, and is applicable to on-site rapid hardness testing of various metallic materials.