The magnitude of change in the Rockwell hardness value that results from a change in the applied force is shown in Figure A.1 for the preliminary force and in Figure A.2 for the total force. The test method standards published by ASTM and ISO provide tolerances for the applied Rockwell forces. Summaries of these tolerances are given in Table A.1. Figure A.3 illustrates the possible variation in Rockwell hardness measurement values that can be obtained for the diamond indenter scales while maintaining the forces within the specified tolerances
