This standard is part of the series on test methods for bare wires, used to determine the hardness of copper, aluminum, and their alloy conductors, employing the Brinell hardness testing method. The standard specifies in detail the principles of the test, the required equipment, sample preparation requirements, specific measurement procedures, and the final evaluation method for results. The applicable hardness measurement range has an upper limit of 150 HBW. This standard must be implemented in conjunction with Part 1, "General Principles," of this series to ensure the completeness and standardization of the test. The test primarily relies on the Brinell hardness tester, a key instrument that evaluates the hardness of materials by measuring the indentation diameter. This standard provides a unified basis for testing the mechanical properties of materials in the production of bare wires.