What are the effects of a Rockwell hardness tester on hardness values?

Taiwan Nakazawa Co., Ltd. answers for you: During testing with a Rockwell hardness tester, the specimen is generally a flat surface. If the test is performed on a curved specimen and its radius of curvature is not large, a correction amount should be added to the test result. For convex specimens, since the measured hardness value decreases, a correction amount should be added; for concave specimens, the correction amount should be subtracted.
Cone angle of surface Rockwell hardness testers: The surface Rockwell hardness value increases as the cone angle of the diamond indenter increases. For 30N and 45N scales, the change in angle has a significant impact on low hardness and a small impact on high hardness. For 15N scales and the high hardness values of 30N scales, there is almost no impact. The loading speed of the Rockwell hardness tester will also affect the hardness value.