Overview
EN ISO 6506-4:2014 - "Metallic materials - Brinell hardness test - Part 4: Table of hardness values (ISO 6506-4:2014)" is a standardized reference table for converting measured indentation diameters into Brinell hardness numbers (HBW) when testing metallic materials on flat surfaces. This part of ISO 6506 complements the Brinell test method and calibration parts by providing the authoritative table of hardness values used in Brinell hardness testing.
Key topics
- Scope: Provides the table of Brinell hardness values for use in tests on flat surfaces only.
- Force–diameter index: Values are based on the nominal index 0,102 × F/D (force divided by ball diameter). This index is used to derive consistent hardness values across different indenter sizes and test forces.
- Ball indenters and test forces: The standard covers common ball indenter diameters (for example D = 30, 15, 10, 5, 2.5, 1 mm) and associated test forces; Table 1 in the document lists recommended test forces for each indenter.
- Hardness table (Table 2): Lists mean indentation diameters (d) against the corresponding Brinell hardness numbers (HBW) for the supported force–diameter indices.
- Interpolation rule: When a measured indentation diameter is not tabulated, a linear interpolation between the two adjacent tabulated diameters and hardness values is required.
- Significant figures and calculation method: Hardness values are quoted to three significant figures but are calculated from the nominal force–diameter index (not directly from the specified force) to avoid small variations. The standard notes this method can occasionally produce a one-digit difference in the least significant figure.
Applications
EN ISO 6506-4:2014 is used wherever Brinell hardness testing is performed and accurate conversion from indentation diameter to HBW is required:
- Metallurgical and materials testing laboratories performing routine Brinell hardness tests on flat samples.
- Quality control and inspection in manufacturing industries (steel, non-ferrous metals, castings) where hardness acceptance criteria are specified.
- Calibration and verification processes that require standardized reference values for hardness conversion.
- R&D and failure analysis where consistent, comparable hardness data are necessary for material characterization.
Keywords: EN ISO 6506-4:2014, Brinell hardness test, table of hardness values, HBW, force–diameter index, metallic materials, hardness testing, flat surfaces.
Related standards
- ISO 6506-1 - Test method (procedure for Brinell hardness test)
- ISO 6506-2 - Verification and calibration of testing machines
- ISO 6506-3 - Calibration of reference blocks
EN ISO 6506-4:2014 should be used together with Parts 1–3 to ensure complete, traceable, and standardized Brinell hardness testing practice.
