This standard specifies the core procedures for Brinell hardness testing of metallic materials. The test is performed using a Brinell hardness tester, where a hard metal ball indenter of specified diameter is pressed into the surface of the specimen under a defined test force. After maintaining the force for a specified duration, it is removed, and the Brinell hardness value is calculated by measuring the average diameter of the residual indentation on the specimen surface. The standard applies to both stationary and portable types of Brinell hardness testers. Compared to the previous edition, the new version strengthens operational norms, explicitly requiring daily verification of the hardness tester according to JJG 150 before testing, and stipulating that the indentation measuring device must have uniform field illumination. These revisions aim to enhance the accuracy and consistency of measurement results.