Brinell Sertlik

What Is Brinell Hardness?

In the Brinell method, a hard metal ball is pressed into the specimen surface with a defined force; after the force is removed, the resulting indentation's diameter is measured in two directions and the hardness value is calculated. The indentation is relatively large, making the method suitable for heterogeneous and coarse-grained materials.

Purpose of Brinell Hardness

The purpose is to obtain a highly representative hardness value for castings, forgings and coarse-structured materials. The large indentation averages out local structural differences in the material, giving a more stable result.

Which Products Is Brinell Hardness Applied To?

Castings and forgings
Hot-rolled steel products
Non-ferrous metals and alloys
Coarse-grained and heterogeneous materials
Thick-section structural elements

In Which Sectors Is Brinell Hardness Used?

MetalAutomotiveAerospaceConstructionMachinery Manufacturing

Standards Related to Brinell Hardness

ISO 6506-1 (Brinell hardness test — test method)
ISO 6506-2 (verification and calibration of testing machines)
ISO 6506-3 (calibration of reference blocks)
ASTM E10 (Brinell hardness of metallic materials)

Brinell Hardness Conditions

Indenter: Hard metal ball; diameter selected per material and thickness
Test force: From the force-diameter ratio dependent on ball diameter, per the standard's table
Dwell time: Defined in the standard; may be extended per the material
Measurement: The indentation diameter is measured in two perpendicular directions and averaged

Equipment for Brinell Hardness

Brinell hardness testing machine
Hard metal ball indenters
Indentation measuring microscope or automatic image analysis system
Hardness reference blocks
Specimen surface preparation equipment

Sample Requirements for Brinell Hardness

The surface must be smooth and clean enough to allow indentation measurement.
Specimen thickness must be sufficient that the indentation causes no effect on the back face.
Measurement points must be spaced from the edge and from each other by the distances defined in the standard.
The specimen must be supported so it does not move during the test.
Surface preparation must not heat the material and alter its structure.

Duration of Brinell Hardness

A single measurement takes minutes. Total duration depends on the number of measurement points and surface preparation.

Brinell Hardness Procedure

1The specimen surface is prepared and cleaned.
2Ball diameter and test force are selected from the standard's table.
3The machine is verified with a reference block.
4Force is applied smoothly and held for the defined time.
5The force is removed and the indentation diameter is measured in two directions.
6The hardness value is calculated or read from the machine.
7The measurement is repeated the number of times defined in the standard.

Brinell Hardness Acceptance Criteria

The method standard defines how the test is performed, not what the result should be. The acceptance limit comes from the material standard, the product specification or the customer's technical drawing; this page therefore gives no numerical limit.

Evaluation of Results

The result is reported with the full designation stating the ball diameter and force used (e.g. HBW 10/3000). Brinell values taken under different conditions are not directly comparable. Hardness-to-tensile-strength conversions are made only with tables valid for the relevant material.

Brinell Hardness Report

Specimen identification, material type and cast/batch number, if any
Specimen geometry, dimensions and preparation method
Standard and test conditions applied
Test temperature and ambient conditions
Measured values and calculated quantities
Fracture surface or indentation photographs (where applicable)
Measurement uncertainty (if requested)
A statement that the result applies only to the specimen submitted for testing

Accreditation

EUROLAB holds internationally recognised accreditation obtained from accreditation bodies party to the IAF and ILAC multilateral recognition arrangements, under ISO/IEC 17025 for laboratory testing, ISO/IEC 17020 for inspection and surveillance, and ISO/IEC 17021-1 and ISO/IEC 17065 for system and product certification. This chain ensures the reports and certificates issued are accepted worldwide.

Whether this test can be offered within accredited scope depends on your product and the standard applied; since accreditation is method-based, the scope is confirmed in writing at the quotation stage.

Scope and authorisations

Related Regulations

EN 10204 (inspection documents for metallic products)
EU 305/2011 Construction Products Regulation (for products used in construction)
Harmonised standards applied according to the product family

Mekanik Testler — What Does This Testing Field Cover?

The section below describes the field that the Brinell Hardness test belongs to; the conditions and acceptance criteria of this particular test are given in the sections above. The scope specific to your product is confirmed in writing at the quotation stage.

Mechanical testing measures how a material or a part behaves under force. The family ranges from static loading (tension, compression, bending) to time-dependent behaviour (fatigue, creep), and from hardness and wear to fracture toughness.

What these tests have in common is that the result is reported as a MATERIAL PROPERTY. Yield strength or hardness is not a conformity decision; it is numerical data against which the design and the product standard will compare. Mechanical test reports are therefore usually an input to an engineering decision rather than to a product approval — material selection, safety factor, life prediction.

The distinction between static and dynamic behaviour is the key to understanding the field. A part may appear entirely unstressed under a static load yet break under repeated loading; fatigue fracture occurs at stresses well below the yield strength and gives no warning. For rotating, vibrating or cyclically loaded parts, a tensile test alone is therefore not sufficient evidence.

Test conditions determine the result, and this is critical for the readability of the report: specimen geometry, loading rate, temperature, conditioning and the gripping arrangement. The same material gives different values under different conditions. In plastics the rate effect is very pronounced, in metals the temperature effect; in composites the specimen orientation changes the result entirely.

Hardness is the most misused measurement in the field. Because it is fast, close to non-destructive and inexpensive, it is often used in place of strength. Conversion tables from hardness to strength exist, but they are APPROXIMATE and depend on the material group; using them as the sole evidence in material acceptance is wrong.

The fracture mechanics side requires a specific competence. Fracture toughness and fatigue crack growth rate measurements make it possible to calculate how long a cracked structure will last; they are the basis of damage-tolerant design in fields such as pressure equipment, aircraft structures and pipelines.

Method groups in this field

Static tests
Tension, compression, bending, shear and torsion. Yield and tensile strength, elongation and modulus of elasticity are obtained.
Impact tests
Charpy and Izod notch impact; the brittle-to-ductile transition behaviour of the material is determined as a function of temperature.
Hardness
Brinell, Vickers, Rockwell, Shore and micro hardness. Valuable for surface treatment depth and local differences in strength.
Fatigue
Force- and strain-controlled axial fatigue, fatigue in bending; S-N curves and the endurance limit.
Creep and stress relaxation
Behaviour under long-term load at high temperature; decisive for boiler, turbine and pressure equipment materials.
Fracture mechanics
Plane-strain fracture toughness, the J integral, CTOD and fatigue crack growth rate.
Wear and friction
Taber and rotating drum abrasion, coefficient of friction measurements.

Commonly confused in this field

Calculating strength from hardness is approximate; it cannot be used as the sole evidence in material acceptance.
Adequate static strength does not demonstrate fatigue strength; a cyclically loaded part requires a separate test.
If test rate and temperature are not reported, the result cannot be compared — especially for polymers and composites.
A test specimen and the actual part may not give the same value; moulding orientation, weld lines and differences in surface treatment all have an effect.
A strength value given for a composite without stating the specimen orientation is meaningless.
ASTM and ISO counterparts measure the same quantity but use different specimen geometries; the results are not treated as directly equivalent.

Which decisions these results support

Design verification and material selection
Incoming material control and supplier approval
Meeting the mechanical requirements of the product standard
Failure analysis, life prediction and damage tolerance calculation
Verifying heat treatment and surface treatment processes

Related Tests

Frequently Asked Questions About Brinell Hardness

When is Brinell unsuitable?

For thin sections, hardened surfaces or small parts, the indentation is too large. Vickers or Rockwell is preferred in these cases.

Can tensile strength be calculated from hardness?

Only approximately, and only for materials with an available conversion table. The conversion is not universal; a tensile test must be performed for a definitive value.