ASTM E10 is the Standard Test Method for Brinell Hardness of Metallic Materials, published and maintained by ASTM International (formerly the American Society for Testing and Materials). It defines how a hardened tungsten carbide ball indenter is pressed into a metal specimen under a specified force so that the resulting indentation diameter can be converted into a Brinell hardness number (HBW) that is comparable across laboratories worldwide.
What ASTM E10 covers
ASTM E10 applies to the determination of Brinell hardness of metallic materials by the Brinell indentation hardness principle. The standard covers the test method itself, verification of Brinell hardness testing machines, and calibration of standardized hardness test blocks used to check those machines.
The physical principle is straightforward. A tungsten carbide ball of diameter D (typically 10 mm, 5 mm, 2.5 mm or 1 mm) is forced into the surface of the test piece under a specified test force F, held for a defined dwell time, then removed. The mean diameter d of the residual indentation is measured optically in two perpendicular directions and averaged.
The Brinell hardness value is calculated as:
HBW = 0.102 × (2F) / [πD(D − √(D² − d²))]
where F is the test force in newtons, D is the ball diameter in millimetres and d is the mean indentation diameter in millimetres. The factor 0.102 converts the force from newtons back to the historical kgf basis so that modern HBW values remain numerically consistent with legacy Brinell data. The result is reported with the ball diameter and load, for example 250 HBW 10/3000, meaning a Brinell hardness of 250 obtained with a 10 mm tungsten carbide ball at a 3000 kgf test force.
The standard also specifies the load-diameter ratio (0.102 F/D²) used to select an appropriate test force for a given material group, minimum specimen thickness (at least ten times the indentation depth), minimum spacing between indentations and from the edge of the specimen, and the surface finish required for reliable optical measurement.
Why it matters for procurement
Government tenders, university purchase committees and industrial buyers routinely specify Brinell hardness testers as compliant with ASTM E10 or its ISO equivalent. Writing the standard into the specification protects the buyer: it fixes the indenter geometry, the load ranges, the verification regime and the reporting format, so bids from different manufacturers can be compared like for like.
In practice a well-written tender will call out ASTM E10 together with its ISO and national equivalents, allow either a direct-loading or a closed-loop load-cell machine, and require calibration traceability to standardized test blocks. Buyers should also confirm that the supplied indenter is tungsten carbide (the current ASTM E10 requirement) rather than the older hardened steel ball, which is no longer permitted under the current revision of the standard.
Equivalent international standards
| Body | Standard | Title / scope |
|---|---|---|
| ASTM International | ASTM E10 | Standard Test Method for Brinell Hardness of Metallic Materials |
| ISO | ISO 6506-1 | Metallic materials — Brinell hardness test — Part 1: Test method |
| ISO | ISO 6506-2 / -3 / -4 | Verification of machines / calibration of reference blocks / tables of hardness values |
| Bureau of Indian Standards | IS 1500 (Part 1) | Metallic materials — Brinell hardness test (aligned with ISO 6506-1) |
| European Norm | EN ISO 6506-1 | European adoption of ISO 6506-1 |
| Japanese Industrial Standard | JIS Z 2243 | Brinell hardness test — Test method |
| Deutsches Institut für Normung | DIN EN ISO 6506-1 | German adoption of the ISO method |
ASTM E10 and the ISO 6506 series are technically aligned on indenter geometry, load-diameter ratios and reporting conventions, so a machine built to one is generally acceptable under the other, provided the calibration certificates trace to the correct reference blocks.
Testing procedure summary
- Prepare the specimen. The test surface must be flat, clean and free of scale, oxide or lubricant. Surface roughness should be fine enough that the edges of the indentation can be measured optically without ambiguity.
- Select ball diameter and test force. Choose the ball (typically 10, 5, 2.5 or 1 mm) and the corresponding force so that the load-diameter ratio 0.102 F/D² suits the material group (for example, 30 for steels and cast irons, 10 for copper alloys, 5 or 2.5 for softer non-ferrous metals).
- Apply the load. Bring the indenter into contact and apply the full test force smoothly, without shock or vibration, within the time window specified in the standard.
- Hold the dwell time. Maintain the full force for 10 s to 15 s for ferrous materials, or the longer dwell (typically 10 s to 30 s) required for softer materials that continue to creep under load.
- Measure the indentation. Remove the load, then measure the mean diameter of the indentation in two perpendicular directions using a calibrated measuring microscope or an integrated optical system. Average the two readings.
- Calculate and report. Compute HBW from the equation above (or read from the standardized tables) and report the value in the ASTM E10 format, for example 187 HBW 2.5/187.5, along with the dwell time if it differs from the default.
Scientico compliance
Scientico India supplies Brinell hardness testing machines and combined Rockwell / Brinell / Vickers universal testers built to operate within the load ranges, indenter geometries and measurement conventions defined by ASTM E10 and the equivalent ISO 6506-1 method. Machines are offered with tungsten carbide ball indenters, standardized reference test blocks, and calibration documentation so buyers can verify performance on installation and at scheduled intervals in service.
Related Scientico equipment
- Brinell hardness testing machine (bench model, 10 mm ball, 3000 kgf capability)
- Universal hardness tester (Brinell / Rockwell / Vickers on a single frame)
- Digital Brinell microscope for indentation measurement
- Standardized Brinell test blocks (traceable reference blocks)
- Tungsten carbide ball indenters in 10, 5, 2.5 and 1 mm diameters
- Materials testing bench sets for engineering and polytechnic laboratories
Related pages
Frequently Asked Questions
What is ASTM E10?
ASTM E10 is the Standard Test Method for Brinell Hardness of Metallic Materials, published by ASTM International. It defines the indenter, loads, procedure, machine verification and reporting format for the Brinell hardness test.
What is the ISO equivalent of ASTM E10?
The direct equivalent is ISO 6506-1 (Metallic materials, Brinell hardness test, Part 1: Test method). ISO 6506-2, -3 and -4 cover machine verification, reference-block calibration and hardness value tables respectively.
What indenter does ASTM E10 require?
The current revision of ASTM E10 requires a tungsten carbide ball indenter in nominal diameters of 10, 5, 2.5 or 1 mm. Hardened steel balls, used under older revisions, are no longer permitted.
How is a Brinell hardness value reported?
As HBW followed by ball diameter and test force in kgf, for example 250 HBW 10/3000, meaning HBW = 250 measured with a 10 mm tungsten carbide ball at 3000 kgf. Dwell time is added if it differs from the default 10 to 15 s.
What test force should I use?
Select the force from the load-diameter ratio 0.102 F/D squared appropriate to the material group: typically 30 for steels and cast irons, 10 for copper alloys, and 5 or 2.5 for softer non-ferrous metals, per the tables in ASTM E10.
Does Scientico supply Brinell testers to ASTM E10?
Yes. Scientico manufactures Brinell and universal hardness testers built to operate within the load ranges, geometries and measurement conventions of ASTM E10 and ISO 6506-1, supplied with tungsten carbide indenters and traceable reference blocks. Request a CIF quote on WhatsApp.
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