DIN EN ISO 6508-2:2015-06

This part of ISO 6508 specifies two separate methods of verification of testing machines (direct and indirect) for determining Rockwell hardness in accordance with ISO 6508-1:2015, together with a method for verifying Rockwell hardness indenters. The direct verification method is used to determine whether the main parameters associated with the machine function, such as applied force, depth measurement, and testing cycle timing, fall within specified tolerances. The indirect verification method uses a number of calibrated reference hardness blocks to determine how well the machine can measure a material of known hardness. The indirect method may be used on its own for periodic routine checking of the machine in service. If a testing machine is also to be used for other methods of hardness testing, it shall be verified independently for each method. This part of ISO 6508 is applicable to stationary and portable hardness testing machines. Attention is drawn to the fact that the use of tungsten carbide composite for ball indenters is considered to be the standard type of Rockwell indenter ball. Steel indenter balls may continue to be used only when complying with ISO 6508-1:2015, Annex A. This document (EN ISO 6508-2:2015) has been prepared by Technical Committee ISO/TC 164 "Mechanical testing of metals", Subcommittee SC 3 "Hardness testing" (secretariat: DIN, Germany) and adopted by Technical Committee ECISS/TC 101 "Test methods for steel (other than chemical analysis)" (secretariat: AFNOR, France) in accordance with the agreement on technical cooperation between ISO and CEN (Vienna Agreement). The responsible German committee is Working Committee NA 062-01-41 AA "Härteprüfung für Metalle" ("Hardness testing for metals") at the Materials Testing Standards Committee (NMP).