Overview
EN ISO 6507-2:2018 - “Metallic materials - Vickers hardness test - Part 2: Verification and calibration of testing machines” specifies procedures for verifying and calibrating Vickers hardness testing machines and the diagonal measuring systems used to determine Vickers hardness (in accordance with ISO 6507‑1). The standard describes both a direct method (calibration of force, indenter and measuring system) and an indirect method (overall checking using reference blocks). It applies to bench and portable hardness testing machines, but not to systems based on different measurement principles (e.g. ultrasonic impedance).
Key topics and technical requirements
- Direct verification elements
- Calibration of the test force across the machine working range; measure at not less than three plunger positions unless a closed‑loop system is proven position‑independent.
- Verification of the Vickers indenter geometry and mounting.
- Calibration and verification of the diagonal length measuring system (measuring microscope / optics).
- Verification of the testing cycle (force application/removal behavior).
- Indirect verification
- Use of reference blocks (calibrated reference indentations) for overall machine checking, with requirements for number of indentations, force levels and measurement procedures.
- Metrological controls
- Instruments used for verification must be traceable to national standards.
- Force calibration may use an elastic proving device per ISO 376 (class 1) or calibrated masses/force standards with about ±0.2% accuracy.
- Environmental condition guidance: direct verification recommended at (23 ± 5) °C; deviations must be reported.
- Requirements on uncertainty of calibration/verification and reporting (see Annex A).
- Scope constraints
- If a machine is used for multiple hardness methods it must be verified separately for each method.
- Not applicable to hardness testers using other measurement principles.
Applications and users
- Intended for: calibration laboratories, material testing labs, quality control/inspection departments, metallurgical labs, manufacturers of hardness testing equipment, and calibration service providers.
- Practical uses:
- Ensuring reliable Vickers hardness results for material certification and acceptance testing.
- Establishing traceability and documented calibration records for audits and conformity assessment.
- Periodic verification scheduling, acceptance after repair, or pre‑use checks for portable testers.
Related standards
- ISO 6507-1 - Vickers hardness test: test method (measurement procedure).
- ISO 6507-3 - Calibration of reference blocks.
- ISO 376 - Calibration of force‑proving instruments (used for force calibration).
EN ISO 6507-2:2018 is a key standard for anyone responsible for accurate Vickers hardness measurement, calibration traceability, and ensuring measurement uncertainty and reporting meet international practice.
