Overview
ISO 6506-4:2014 - "Metallic materials - Brinell hardness test - Part 4: Table of hardness values" provides the official tabulated Brinell hardness (HBW) reference values for tests carried out on flat surfaces. The part complements the Brinell test method by giving the relationship between mean indentation diameter, ball indenter size and the Brinell hardness number. Tables in the standard enable direct conversion of measured indentation diameters to HBW values for standard ball indenters and test forces.
Keywords: ISO 6506-4, Brinell hardness table, HBW, Brinell hardness test, metallic materials, indentation diameter.
Key topics
- Scope: Tabulated Brinell hardness values specifically for testing on flat surfaces.
- Ball indenter sizes: Tables cover standard ball diameters (D = 30, 15, 10, 5, 2.5, 1 mm) used in Brinell testing.
- Force–diameter index: Uses the index 0.102 × F / D to standardize hardness calculations across forces and indenter sizes.
- Tabulated conversion: Mean indentation diameters (d) are directly linked to HBW values in the tables for each indenter and force combination.
- Interpolation rule: If a measured indentation diameter is not listed, linear interpolation between adjacent table entries is required.
- Numerical conventions: Hardness values are quoted to three significant figures and are calculated from the nominal force–diameter index (to avoid small variations caused by specified force rounding); this can occasionally affect the least significant digit.
Applications
- Routine hardness measurement and reporting in material testing laboratories using the Brinell hardness test.
- Quality control and acceptance testing in manufacturing, heat treatment, welding and metallurgy where hardness of flat components must be verified.
- Conversion of measured indentation diameters to standard HBW values for documentation, certification and technical specifications.
- Reference for test procedures and reporting when using Brinell hardness machines and when correlating results across different indenter sizes and loads.
Keywords: hardness testing standard, HBW table, Brinell conversion table, material testing, QA/QC.
Who uses this standard
- Metallurgists and materials engineers performing Brinell hardness testing.
- Laboratory technicians and calibration labs that verify hardness test results.
- Quality and inspection personnel in manufacturing and heat-treatment facilities.
- Standards committees and technical authors referencing authoritative HBW conversion tables.
Related standards
ISO 6506 is a multipart standard:
- Part 1: Test method (procedure for conducting Brinell tests)
- Part 2: Verification and calibration of testing machines
- Part 3: Calibration of reference blocks
- Part 4: This document - Table of hardness values
Use ISO 6506-4 together with Parts 1–3 to ensure compliant Brinell hardness measurement, machine verification and result traceability.
