ISO 6508-2-2023 PDF

Full title and description

Metallic materials — Rockwell hardness test — Part 2: Verification and calibration of testing machines and indenters. This International Standard specifies methods for verifying and calibrating Rockwell hardness testing machines (direct and indirect verification) and for verifying indenters used in Rockwell testing.

Abstract

ISO 6508-2:2023 defines two verification approaches for Rockwell hardness testers: a direct method that checks machine functions (test forces, depth‑measuring system, testing cycle timing and machine hysteresis) and an indirect method that uses calibrated reference hardness blocks to assess measurement performance. It also includes procedures for verification and calibration of diamond and ball indenters and requirements for environmental conditions and traceability.

General information

• Status: Published.
• Publication date: December 2023 (published 2023-12).
• Publisher: International Organization for Standardization (ISO).
• ICS / categories: 77.040.10 (Mechanical testing of metals / Hardness testing).
• Edition / version: Edition 4 (ISO 6508-2:2023).
• Number of pages: 23 pages.

Scope

Specifies methods for verification and calibration of testing machines used for Rockwell hardness determination in accordance with ISO 6508-1, and for verification/calibration of Rockwell indenters. The standard is applicable to both stationary and portable hardness testing machines and addresses both direct (instrumental checks) and indirect (reference‑block comparison) verification procedures. Attention is given to traceability, environmental conditions for verification, and required documentation of results.

Key topics and requirements

• Direct verification of machine parameters: measurement/calibration of preliminary and total test forces, depth‑measuring system calibration, testing cycle timing checks, and machine hysteresis tests.
• Indirect verification using calibrated reference hardness blocks across specified hardness ranges to assess bias, repeatability and overall measurement uncertainty.
• Procedures for verification and calibration of indenters (diamond cone and ball indenters), including geometric checks (cone angle, tip radius) and indirect verification via reference blocks.
• Performance tolerances and measurement limits (examples: permissible relative errors on force measurements — preliminary ±2.0 %, total ±1.0 %; specified depth‑measurement tolerances — see standard for scale‑specific values).
• Environmental and traceability requirements: recommended ambient conditions for direct verification (typically (23 ± 5) °C), use of instruments traceable to national standards, and documented verification reports and intervals.
• Identification of tungsten‑carbide (hard metal) composite as the standard material for Rockwell ball indenters (standard ball type) and related notes on allowable alternatives.

Typical use and users

Used by calibration and materials testing laboratories, quality and metrology departments in manufacturing, hardness‑testing equipment manufacturers and service engineers, and accreditation bodies. The standard guides periodic verification, post‑repair calibration, machine qualification for specific scales, and maintenance of measurement traceability.

Related standards

Part of the ISO 6508 series on Rockwell hardness testing: ISO 6508-1 (Test method — Part 1: Test method) and ISO 6508-3 (Calibration of reference blocks — Part 3) are directly related and should be used together for complete implementation and traceable calibration. ISO/TC 164/SC 3 provides the technical committee context for these documents.

Keywords

Rockwell hardness, hardness testing, verification, calibration, testing machine, indenter, reference blocks, depth measurement, test force, traceability, measurement uncertainty, ISO 6508-2:2023.

FAQ

Q: What is this standard?

A: ISO 6508-2:2023 is the fourth‑edition International Standard that specifies verification and calibration methods for Rockwell hardness testing machines and indenters.

Q: What does it cover?

A: It covers two verification methods (direct instrument checks and indirect reference‑block comparisons), procedures for indenter verification (diamond and ball), performance tolerances, environmental and traceability requirements, and reporting/documentation of verification results.

Q: Who typically uses it?

A: Calibration laboratories, industrial quality control and materials testing labs, equipment manufacturers and service engineers, and accreditation/inspection bodies use this standard to ensure Rockwell hardness machines perform within required tolerances.

Q: Is it current or superseded?

A: It is current — ISO 6508-2:2023 was published in December 2023 and replaces earlier editions (including the 2015 edition). Consult the published standard text for any corrigenda or future amendments.

Q: Is it part of a series?

A: Yes — it is Part 2 of the ISO 6508 series on Rockwell hardness testing. Relevant companion documents are ISO 6508-1 (test method) and ISO 6508-3 (calibration of reference blocks). For full implementation, use the three parts together.

Q: What are the key keywords?

A: Rockwell, hardness, calibration, verification, indenter, reference block, test force, depth measurement, measurement uncertainty, traceability (ISO 6508-2:2023).