In the first half of 2007 ASTM Subcommittee E28.06 passed new versions of E18 for Rockwell testing. These new documents took several years to finish and are complete rewrites of the popular test method. There are many technical changes and new document requirements that can have a far reaching effect, especially when you have to satisfy the needs of an auditor. It may be that none of your Rockwell test results meet the new standards.
Rockwell Ball Indenters:
E18-07 and later test methods require that Rockwell ball indenters are to be geometrically verified and adds performance verification as a new testing requirement. Previous E18 ASTM test methods did not require manufacturers to verify the performance of ball indenters. The reasoning for adding a performance requirement in the standard was to ensure consistency in the performance of ball indenters. Ball verification of the indenter consists of geometry, density, hardness and chemical composition verification. There are now (2) separate classes of ball indenters. (Class B & Class A).
- Class B ball indenters have performance verification added on specific hardness scales. These indenters are used for normal everyday hardness testing.
- Class A ball indenters have significantly tighter performance requirements than Class B ball indenters. These indenters are used to calibrate test blocks and testing machines.
For added traceability the ball indenter container or ball indenter must be serialized. All Wilson balls and ball indenters meet the tighter Class A specification above at no additional cost to our customers.
The impact of these changes makes all pre E18-07 ball indenters obsolete. In order to comply with the new requirements you must obtain new ball indenters that comply with the latest ASTM test methods.
Rockwell Testers:
With all of the above changes to test blocks and indenters your Rockwell tester will need to be reverified to E18-07 or later to ensure compliant test results.