ISO 6508 defines the international standard for Rockwell hardness testing, one of the most widely used methods for measuring the hardness of metallic materials. It provides the procedures, equipment specifications, and performance criteria required to ensure consistent and traceable results across laboratories and industries.
ISO 6508 specifies the methods for Rockwell hardness testing of metallic materials using either a diamond cone (brale) or a carbide ball indenter. It defines the test procedure, test forces, dwell times, and scales used to determine hardness values.
The standard is divided into three main parts:
By following ISO 6508, manufacturers and laboratories can ensure that their Rockwell test results are accurate, comparable, and accepted internationally. This is essential in industries such as automotive, aerospace, and metal production, where hardness data is critical for quality assurance and product calibration.
UPI Laboratories supports companies worldwide in achieving and maintaining compliance with ISO 6508 by providing accredited calibration of calibrated hardness test blocks and indenters.
The Rockwell test measures the hardness of a material based on the depth of penetration caused by a specified load applied through an indenter. The test sequence includes applying a preliminary load, a main load, and then returning to the preliminary load while measuring the indentation depth difference.
Our diamond cone (brale) indenters are manufactured with high-precision alignment to ensure consistency in hardness readings. Each diamond indenter supplied by UPI Laboratories is dual calibrated to ISO and ASTM standards, guaranteeing traceability and conformity with ISO 6508. The diamonds are carefully mounted according to their grain structure, ensuring long life and reliable performance.
For softer materials or specific Rockwell scales, carbide ball indenters are used. UPI Laboratories provides carbide balls made from the highest purity materials and inspects them using laser scanning microscopes to verify diameter accuracy and roundness. These indenters meet all ISO and ASTM specifications for Rockwell testing.
To verify and calibrate Rockwell testing machines, reference test blocks are required. UPI Laboratories supplies Rockwell test blocks made from homogenous materials with mirror or matte finishes. Each block is laser engraved, traceable, and calibrated according to ISO 6508-3 and ASTM E18. Test blocks can also be supplied with NADCAP-compliant grids for aerospace applications.
Compliance with ISO 6508 starts with using properly calibrated hardness test blocks, indenters and calibrated testing procedures. To meet ISO 6508 and audit requirements, each Rockwell hardness tester must be periodically checked for:
By using ISO 6508-compliant indenters and test blocks supplied by UPI Laboratories, you ensure consistent, traceable results across your entire testing process.
ISO/IEC 17025 accreditation confirms that calibration activities are performed using validated methods, controlled equipment, and documented procedures. For Rockwell hardness testing under ISO 6508, this ensures that indenter geometry, applied loads, and reference blocks are calibrated within defined tolerances.
Whether hardness testing is performed in a laboratory environment or on the production floor, compliance with ISO 6508 depends on reliable equipment and traceable calibration.
UPI Laboratories Europe BV supports organizations worldwide with ISO 6508-compliant Rockwell diamond and carbide ball indenters and calibrated reference blocks. All products are calibrated under ISO/IEC 17025 accreditation granted by the RvA, ensuring consistency, traceability.
Looking for support with Rockwell testing or ISO 6508 compliance? Contact UPI Laboratories Europe BV or download our catalogue for technical specifications and calibration options.