SIST EN ISO 6508-2:2024 PDF

Overview

EN ISO 6508-2:2023 - "Metallic materials - Rockwell hardness test - Part 2" specifies methods for the verification and calibration of Rockwell hardness testing machines and indenters. It defines two complementary verification approaches (direct and indirect) and a method for verifying indenter condition. The document applies to both stationary and portable hardness testers and aligns with ISO 6508‑1 (test method) and ISO 6508‑3 (reference blocks).

Key topics and technical requirements

• Two verification methods
  • Direct verification: calibrates and verifies machine functions such as applied test forces, depth-measuring system, testing cycle timing, and machine hysteresis. Direct checks should normally be carried out at (23 ± 5) °C and use instruments traceable to national standards. Force measurements are made at multiple plunger positions.
  • Indirect verification: uses calibrated reference hardness blocks to assess how well the machine measures materials of known Rockwell hardness (bias, repeatability, uncertainty).
• Indenter verification
  • Procedures for diamond and ball indenters, including both direct calibration/verification and indirect verification via block comparisons.
  • Note: tungsten carbide composite is considered the standard material for Rockwell ball indenters.
• Measurement quality
  • Addresses repeatability, bias, and uncertainty of measurement (Annex B), and includes a normative annex on repeatability (Annex A).
• Traceability and reporting
  • Calibration instruments must be traceable to national standards and verifications must be recorded in a verification report. The standard also covers intervals between verifications.

Applications and who uses it

• Metrology and calibration laboratories performing routine accreditation and traceable calibration of hardness testers.
• Manufacturers of Rockwell hardness testing machines and indenter assemblies for machine acceptance and production control.
• Quality control and inspection departments in metalworking, heat treatment, automotive, aerospace, and steel industries that rely on accurate hardness measurements.
• Research and certification bodies validating Rockwell measurement capability using reference blocks.

Related standards

• ISO 6508-1 - Rockwell hardness test - Part 1: Test method
• ISO 6508-3 - Calibration of reference hardness blocks
• ISO 376 - Calibration of force‑proving instruments
• ISO 6507-1 - Vickers hardness test - Part 1: Test method

EN ISO 6508-2:2023 is essential for ensuring reliable Rockwell hardness measurement through systematic verification and calibration of both machines and indenters.