Abstract: The Rockwell hardness test was perform on copper tube samples, the uncertainty of measurement results was evaluated, and the factors that affect the accuracy of test results were analyzed. The results show that the measurement uncertainty of the Rockwell hardness test for copper pipes mainly came from the repeatability of the Rockwell hardness test, the use of standard materials to measure the Rockwell hardness tester, standard hardness blocks, the indication error of the hardness tester, the resolution of the indentation measurement system, and data rounding. Among them, the maximum allowable error of the hardness tester, measurement repeatability, and the uniformity of the standard block had a significant impact on the measurement uncertainty. Therefore, choosing a high-precision and stable hardness tester, a standard hardness block with good uniformity, and improving the professional competence and operational skills of the testing personnel could make the test results more accurate and reliable.